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* Merge android-4.4@59ff2e1 (v4.4.78) into msm-4.4Blagovest Kolenichev2017-08-04
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * refs/heads/tmp-59ff2e1 Linux 4.4.78 kvm: vmx: allow host to access guest MSR_IA32_BNDCFGS kvm: vmx: Check value written to IA32_BNDCFGS kvm: x86: Guest BNDCFGS requires guest MPX support kvm: vmx: Do not disable intercepts for BNDCFGS KVM: x86: disable MPX if host did not enable MPX XSAVE features tracing: Use SOFTIRQ_OFFSET for softirq dectection for more accurate results PM / QoS: return -EINVAL for bogus strings PM / wakeirq: Convert to SRCU sched/topology: Optimize build_group_mask() sched/topology: Fix overlapping sched_group_mask crypto: caam - fix signals handling crypto: sha1-ssse3 - Disable avx2 crypto: atmel - only treat EBUSY as transient if backlog crypto: talitos - Extend max key length for SHA384/512-HMAC and AEAD mm: fix overflow check in expand_upwards() tpm: Issue a TPM2_Shutdown for TPM2 devices. Add "shutdown" to "struct class". tpm: Provide strong locking for device removal tpm: Get rid of chip->pdev selftests/capabilities: Fix the test_execve test mnt: Make propagate_umount less slow for overlapping mount propagation trees mnt: In propgate_umount handle visiting mounts in any order mnt: In umount propagation reparent in a separate pass vt: fix unchecked __put_user() in tioclinux ioctls exec: Limit arg stack to at most 75% of _STK_LIM s390: reduce ELF_ET_DYN_BASE powerpc: move ELF_ET_DYN_BASE to 4GB / 4MB arm64: move ELF_ET_DYN_BASE to 4GB / 4MB arm: move ELF_ET_DYN_BASE to 4MB binfmt_elf: use ELF_ET_DYN_BASE only for PIE checkpatch: silence perl 5.26.0 unescaped left brace warnings fs/dcache.c: fix spin lockup issue on nlru->lock mm/list_lru.c: fix list_lru_count_node() to be race free kernel/extable.c: mark core_kernel_text notrace tools/lib/lockdep: Reduce MAX_LOCK_DEPTH to avoid overflowing lock_chain/: Depth parisc/mm: Ensure IRQs are off in switch_mm() parisc: DMA API: return error instead of BUG_ON for dma ops on non dma devs parisc: use compat_sys_keyctl() parisc: Report SIGSEGV instead of SIGBUS when running out of stack irqchip/gic-v3: Fix out-of-bound access in gic_set_affinity cfg80211: Check if PMKID attribute is of expected size cfg80211: Validate frequencies nested in NL80211_ATTR_SCAN_FREQUENCIES cfg80211: Define nla_policy for NL80211_ATTR_LOCAL_MESH_POWER_MODE brcmfmac: fix possible buffer overflow in brcmf_cfg80211_mgmt_tx() rds: tcp: use sock_create_lite() to create the accept socket vrf: fix bug_on triggered by rx when destroying a vrf net: ipv6: Compare lwstate in detecting duplicate nexthops ipv6: dad: don't remove dynamic addresses if link is down net: handle NAPI_GRO_FREE_STOLEN_HEAD case also in napi_frags_finish() bpf: prevent leaking pointer via xadd on unpriviledged net: prevent sign extension in dev_get_stats() tcp: reset sk_rx_dst in tcp_disconnect() net: dp83640: Avoid NULL pointer dereference. ipv6: avoid unregistering inet6_dev for loopback net/phy: micrel: configure intterupts after autoneg workaround net: sched: Fix one possible panic when no destroy callback net_sched: fix error recovery at qdisc creation ANDROID: android-verity: mark dev as rw for linear target ANDROID: sdcardfs: Remove unnecessary lock ANDROID: binder: don't check prio permissions on restore. Add BINDER_GET_NODE_DEBUG_INFO ioctl UPSTREAM: cpufreq: schedutil: Trace frequency only if it has changed UPSTREAM: cpufreq: schedutil: Avoid reducing frequency of busy CPUs prematurely UPSTREAM: cpufreq: schedutil: Refactor sugov_next_freq_shared() UPSTREAM: cpufreq: schedutil: Fix per-CPU structure initialization in sugov_start() UPSTREAM: cpufreq: schedutil: Pass sg_policy to get_next_freq() UPSTREAM: cpufreq: schedutil: move cached_raw_freq to struct sugov_policy UPSTREAM: cpufreq: schedutil: Rectify comment in sugov_irq_work() function UPSTREAM: cpufreq: schedutil: irq-work and mutex are only used in slow path UPSTREAM: cpufreq: schedutil: enable fast switch earlier UPSTREAM: cpufreq: schedutil: Avoid indented labels Linux 4.4.77 saa7134: fix warm Medion 7134 EEPROM read x86/mm/pat: Don't report PAT on CPUs that don't support it ext4: check return value of kstrtoull correctly in reserved_clusters_store staging: comedi: fix clean-up of comedi_class in comedi_init() staging: vt6556: vnt_start Fix missing call to vnt_key_init_table. tcp: fix tcp_mark_head_lost to check skb len before fragmenting md: fix super_offset endianness in super_1_rdev_size_change md: fix incorrect use of lexx_to_cpu in does_sb_need_changing perf tools: Use readdir() instead of deprecated readdir_r() again perf tests: Remove wrong semicolon in while loop in CQM test perf trace: Do not process PERF_RECORD_LOST twice perf dwarf: Guard !x86_64 definitions under #ifdef else clause perf pmu: Fix misleadingly indented assignment (whitespace) perf annotate browser: Fix behaviour of Shift-Tab with nothing focussed perf tools: Remove duplicate const qualifier perf script: Use readdir() instead of deprecated readdir_r() perf thread_map: Use readdir() instead of deprecated readdir_r() perf tools: Use readdir() instead of deprecated readdir_r() perf bench numa: Avoid possible truncation when using snprintf() perf tests: Avoid possible truncation with dirent->d_name + snprintf perf scripting perl: Fix compile error with some perl5 versions perf thread_map: Correctly size buffer used with dirent->dt_name perf intel-pt: Use __fallthrough perf top: Use __fallthrough tools strfilter: Use __fallthrough tools string: Use __fallthrough in perf_atoll() tools include: Add a __fallthrough statement mqueue: fix a use-after-free in sys_mq_notify() RDMA/uverbs: Check port number supplied by user verbs cmds KEYS: Fix an error code in request_master_key() ath10k: override CE5 config for QCA9377 x86/uaccess: Optimize copy_user_enhanced_fast_string() for short strings x86/tools: Fix gcc-7 warning in relocs.c gfs2: Fix glock rhashtable rcu bug USB: serial: qcserial: new Sierra Wireless EM7305 device ID USB: serial: option: add two Longcheer device ids pinctrl: sh-pfc: Update info pointer after SoC-specific init pinctrl: mxs: atomically switch mux and drive strength config pinctrl: sunxi: Fix SPDIF function name for A83T pinctrl: meson: meson8b: fix the NAND DQS pins pinctrl: sh-pfc: r8a7791: Fix SCIF2 pinmux data sysctl: report EINVAL if value is larger than UINT_MAX for proc_douintvec sysctl: don't print negative flag for proc_douintvec mac80211_hwsim: Replace bogus hrtimer clockid usb: Fix typo in the definition of Endpoint[out]Request usb: usbip: set buffer pointers to NULL after free Add USB quirk for HVR-950q to avoid intermittent device resets USB: serial: cp210x: add ID for CEL EM3588 USB ZigBee stick usb: dwc3: replace %p with %pK drm/virtio: don't leak bo on drm_gem_object_init failure tracing/kprobes: Allow to create probe with a module name starting with a digit mm: fix classzone_idx underflow in shrink_zones() bgmac: reset & enable Ethernet core before using it driver core: platform: fix race condition with driver_override fs: completely ignore unknown open flags fs: add a VALID_OPEN_FLAGS ANDROID: binder: add RT inheritance flag to node. ANDROID: binder: improve priority inheritance. ANDROID: binder: add min sched_policy to node. ANDROID: binder: add support for RT prio inheritance. ANDROID: binder: push new transactions to waiting threads. ANDROID: binder: remove proc waitqueue FROMLIST: binder: remove global binder lock FROMLIST: binder: fix death race conditions FROMLIST: binder: protect against stale pointers in print_binder_transaction FROMLIST: binder: protect binder_ref with outer lock FROMLIST: binder: use inner lock to protect thread accounting FROMLIST: binder: protect transaction_stack with inner lock. FROMLIST: binder: protect proc->threads with inner_lock FROMLIST: binder: protect proc->nodes with inner lock FROMLIST: binder: add spinlock to protect binder_node FROMLIST: binder: add spinlocks to protect todo lists FROMLIST: binder: use inner lock to sync work dq and node counts FROMLIST: binder: introduce locking helper functions FROMLIST: binder: use node->tmp_refs to ensure node safety FROMLIST: binder: refactor binder ref inc/dec for thread safety FROMLIST: binder: make sure accesses to proc/thread are safe FROMLIST: binder: make sure target_node has strong ref FROMLIST: binder: guarantee txn complete / errors delivered in-order FROMLIST: binder: refactor binder_pop_transaction FROMLIST: binder: use atomic for transaction_log index FROMLIST: binder: add more debug info when allocation fails. FROMLIST: binder: protect against two threads freeing buffer FROMLIST: binder: remove dead code in binder_get_ref_for_node FROMLIST: binder: don't modify thread->looper from other threads FROMLIST: binder: avoid race conditions when enqueuing txn FROMLIST: binder: refactor queue management in binder_thread_read FROMLIST: binder: add log information for binder transaction failures FROMLIST: binder: make binder_last_id an atomic FROMLIST: binder: change binder_stats to atomics FROMLIST: binder: add protection for non-perf cases FROMLIST: binder: remove binder_debug_no_lock mechanism FROMLIST: binder: move binder_alloc to separate file FROMLIST: binder: separate out binder_alloc functions FROMLIST: binder: remove unneeded cleanup code FROMLIST: binder: separate binder allocator structure from binder proc FROMLIST: binder: Use wake up hint for synchronous transactions. Revert "android: binder: move global binder state into context struct." sched: walt: fix window misalignment when HZ=300 ANDROID: android-base.cfg: remove CONFIG_CGROUP_DEBUG ANDROID: sdcardfs: use mount_nodev and fix a issue in sdcardfs_kill_sb Conflicts: drivers/android/binder.c drivers/net/wireless/ath/ath10k/pci.c Change-Id: Ic6f82c2ec9929733a16a03bb3b745187e002f4f6 Signed-off-by: Blagovest Kolenichev <bkolenichev@codeaurora.org>
| * UPSTREAM: cpufreq: schedutil: Avoid reducing frequency of busy CPUs prematurelyChris Redpath2017-07-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The way the schedutil governor uses the PELT metric causes it to underestimate the CPU utilization in some cases. That can be easily demonstrated by running kernel compilation on a Sandy Bridge Intel processor, running turbostat in parallel with it and looking at the values written to the MSR_IA32_PERF_CTL register. Namely, the expected result would be that when all CPUs were 100% busy, all of them would be requested to run in the maximum P-state, but observation shows that this clearly isn't the case. The CPUs run in the maximum P-state for a while and then are requested to run slower and go back to the maximum P-state after a while again. That causes the actual frequency of the processor to visibly oscillate below the sustainable maximum in a jittery fashion which clearly is not desirable. That has been attributed to CPU utilization metric updates on task migration that cause the total utilization value for the CPU to be reduced by the utilization of the migrated task. If that happens, the schedutil governor may see a CPU utilization reduction and will attempt to reduce the CPU frequency accordingly right away. That may be premature, though, for example if the system is generally busy and there are other runnable tasks waiting to be run on that CPU already. This is unlikely to be an issue on systems where cpufreq policies are shared between multiple CPUs, because in those cases the policy utilization is computed as the maximum of the CPU utilization values over the whole policy and if that turns out to be low, reducing the frequency for the policy most likely is a good idea anyway. On systems with one CPU per policy, however, it may affect performance adversely and even lead to increased energy consumption in some cases. On those systems it may be addressed by taking another utilization metric into consideration, like whether or not the CPU whose frequency is about to be reduced has been idle recently, because if that's not the case, the CPU is likely to be busy in the near future and its frequency should not be reduced. To that end, use the counter of idle calls in the timekeeping code. Namely, make the schedutil governor look at that counter for the current CPU every time before its frequency is about to be reduced. If the counter has not changed since the previous iteration of the governor computations for that CPU, the CPU has been busy for all that time and its frequency should not be decreased, so if the new frequency would be lower than the one set previously, the governor will skip the frequency update. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Joel Fernandes <joelaf@google.com> (cherry picked from commit b7eaf1aab9f8bd2e49fceed77ebc66c1b5800718) (simple CPUFREQ_RT_DL vs CPUFREQ_DL usage conflicts) Signed-off-by: Chris Redpath <chris.redpath@arm.com> Change-Id: I531ec02c052944ee07a904dc2a25c59948ee762b
* | sched/tick: Ensure timers does not get queued on isolated cpusOlav Haugan2016-09-24
| | | | | | | | | | | | | | | | Timers should not be queued on isolated cpus. Instead try to find other cpus to queue timer on. Change-Id: I5d849dfd29aa5bb594454473768d7db1da258028 Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
* | sched: use ktime instead of sched_clock for load trackingJoonwoo Park2016-03-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | At present, HMP scheduler uses sched_clock to setup window boundary to be aligned with timer interrupt to ensure timer interrupt fires after window rollover. However this alignment won't last long since the timer interrupt rearms next timer based on time measured by ktime which isn't coupled with sched_clock. Convert sched_clock to ktime to avoid wallclock discrepancy between scheduler and timer so that we can ensure scheduler's window boundary is always aligned with timer. CRs-fixed: 933330 Change-Id: I4108819a4382f725b3ce6075eb46aab0cf670b7e [joonwoop@codeaurora.org: fixed minor conflict in include/linux/tick.h and kernel/sched/core.c. omitted fixes for kernel/sched/qhmp_core.c] Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>
* | sched: tighten up jiffy to sched_clock mappingSteve Muckle2016-03-23
| | | | | | | | | | | | | | | | | | | | | | | | The tick code already tracks exact time a tick is expected to arrive. This can be used to eliminate slack in the jiffy to sched_clock mapping that aligns windows between a caller of sched_set_window and the scheduler itself. Change-Id: I9d47466658d01e6857d7457405459436d504a2ca Signed-off-by: Steve Muckle <smuckle@codeaurora.org> [joonwoop@codeaurora.org: fixed minor conflict in include/linux/tick.h] Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>
* | cpuidle: lpm-levels: Fixes for clockevents_notifyMahesh Sivasubramanian2016-03-22
|/ | | | | | | | The use of clockevents_notify is deprcated and targeted APIs are used instead of the clockevents_notify callbacks. Switch broadcast timer notifications to tick_broadcast_enter and tick_broadcast_exit. Change-Id: I3441873eb4009b105db04f4a18d28ae9ccd07e95
* nohz: Affine unpinned timers to housekeepersVatika Harlalka2015-09-02
| | | | | | | | | | | | | | | | | | | | | | The problem addressed in this patch is about affining unpinned timers. Adaptive or Full Dynticks CPUs are currently disturbed by unnecessary jitter due to firing of such timers on them. This patch will affine timers to online CPUs which are not full dynticks in NOHZ_FULL configured systems. It should not introduce overhead in nohz full off case due to static keys. Signed-off-by: Vatika Harlalka <vatikaharlalka@gmail.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Christoph Lameter <cl@linux.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1441119060-2230-2-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* nohz: Remove useless argument on tick_nohz_task_switch()Frederic Weisbecker2015-07-29
| | | | | | | | | | | | | Leftover from early code. Cc: Christoph Lameter <cl@linux.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
* nohz: Restart nohz full tick from irq exitFrederic Weisbecker2015-07-29
| | | | | | | | | | | | | | | | | | | | | | Restart the tick when necessary from the irq exit path. It makes nohz full more flexible, simplify the related IPIs and doesn't bring significant overhead on irq exit. In a longer term view, it will allow us to piggyback the nohz kick on the scheduler IPI in the future instead of sending a dedicated IPI that often doubles the scheduler IPI on task wakeup. This will require more changes though including careful review of resched_curr() callers to include nohz full needs. Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Christoph Lameter <cl@linux.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
* nohz: Prevent tilegx network driver interruptsChris Metcalf2015-07-29
| | | | | | | | | | | | | | | | | | | | | | | | | Normally the tilegx networking shim sends irqs to all the cores to distribute the load of processing incoming-packet interrupts, so that you can get to multiple Gb's of traffic inbound. However, in nohz_full mode we don't want to interrupt the nohz_full cores by default, so we limit the set of cores we use to only the online housekeeping cores. To make client code easier to read, we introduce a new nohz_full accessor, housekeeping_cpumask(), which returns a pointer to the housekeeping_mask if nohz_full is enabled, and otherwise returns the cpu_possible_mask. Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com> Cc: Christoph Lameter <cl@linux.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
* tick/broadcast: Unbreak CONFIG_GENERIC_CLOCKEVENTS=n buildThomas Gleixner2015-07-07
| | | | | | | | | | | | | Making tick_broadcast_oneshot_control() independent from CONFIG_GENERIC_CLOCKEVENTS_BROADCAST broke the build for CONFIG_GENERIC_CLOCKEVENTS=n because the function is not defined there. Provide a proper stub inline. Fixes: f32dd1170511 'tick/broadcast: Make idle check independent from mode and config' Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* tick/broadcast: Make idle check independent from mode and configThomas Gleixner2015-07-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the broadcast busy check, which prevents the idle code from going into deep idle, works only in one shot mode. If NOHZ and HIGHRES are off (config or command line) there is no sanity check at all, so under certain conditions cpus are allowed to go into deep idle, where the local timer stops, and are not woken up again because there is no broadcast timer installed or a hrtimer based broadcast device is not evaluated. Move tick_broadcast_oneshot_control() into the common code and provide proper subfunctions for the various config combinations. The common check in tick_broadcast_oneshot_control() is for the C3STOP misfeature flag of the local clock event device. If its not set, idle can proceed. If set, further checks are necessary. Provide checks for the trivial cases: - If broadcast is disabled in the config, then return busy - If oneshot mode (NOHZ/HIGHES) is disabled in the config, return busy if the broadcast device is hrtimer based. - If oneshot mode is enabled in the config call the original tick_broadcast_oneshot_control() function. That function needs extra checks which will be implemented in seperate patches. [ Split out from a larger combo patch ] Reported-and-tested-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Suzuki Poulose <Suzuki.Poulose@arm.com> Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com> Cc: Catalin Marinas <Catalin.Marinas@arm.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1507070929360.3916@nanos
* Merge tag 'pm+acpi-4.2-rc1' of ↵Linus Torvalds2015-06-23
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management and ACPI updates from Rafael Wysocki: "The rework of backlight interface selection API from Hans de Goede stands out from the number of commits and the number of affected places perspective. The cpufreq core fixes from Viresh Kumar are quite significant too as far as the number of commits goes and because they should reduce CPU online/offline overhead quite a bit in the majority of cases. From the new featues point of view, the ACPICA update (to upstream revision 20150515) adding support for new ACPI 6 material to ACPICA is the one that matters the most as some new significant features will be based on it going forward. Also included is an update of the ACPI device power management core to follow ACPI 6 (which in turn reflects the Windows' device PM implementation), a PM core extension to support wakeup interrupts in a more generic way and support for the ACPI _CCA device configuration object. The rest is mostly fixes and cleanups all over and some documentation updates, including new DT bindings for Operating Performance Points. There is one fix for a regression introduced in the 4.1 cycle, but it adds quite a number of lines of code, it wasn't really ready before Thursday and you were on vacation, so I refrained from pushing it on the last minute for 4.1. Specifics: - ACPICA update to upstream revision 20150515 including basic support for ACPI 6 features: new ACPI tables introduced by ACPI 6 (STAO, XENV, WPBT, NFIT, IORT), changes related to the other tables (DTRM, FADT, LPIT, MADT), new predefined names (_BTH, _CR3, _DSD, _LPI, _MTL, _PRR, _RDI, _RST, _TFP, _TSN), fixes and cleanups (Bob Moore, Lv Zheng). - ACPI device power management core code update to follow ACPI 6 which reflects the ACPI device power management implementation in Windows (Rafael J Wysocki). - rework of the backlight interface selection logic to reduce the number of kernel command line options and improve the handling of DMI quirks that may be involved in that and to make the code generally more straightforward (Hans de Goede). - fixes for the ACPI Embedded Controller (EC) driver related to the handling of EC transactions (Lv Zheng). - fix for a regression related to the ACPI resources management and resulting from a recent change of ACPI initialization code ordering (Rafael J Wysocki). - fix for a system initialization regression related to ACPI introduced during the 3.14 cycle and caused by running the code that switches the platform over to the ACPI mode too early in the initialization sequence (Rafael J Wysocki). - support for the ACPI _CCA device configuration object related to DMA cache coherence (Suravee Suthikulpanit). - ACPI/APEI fixes and cleanups (Jiri Kosina, Borislav Petkov). - ACPI battery driver cleanups (Luis Henriques, Mathias Krause). - ACPI processor driver cleanups (Hanjun Guo). - cleanups and documentation update related to the ACPI device properties interface based on _DSD (Rafael J Wysocki). - ACPI device power management fixes (Rafael J Wysocki). - assorted cleanups related to ACPI (Dominik Brodowski, Fabian Frederick, Lorenzo Pieralisi, Mathias Krause, Rafael J Wysocki). - fix for a long-standing issue causing General Protection Faults to be generated occasionally on return to user space after resume from ACPI-based suspend-to-RAM on 32-bit x86 (Ingo Molnar). - fix to make the suspend core code return -EBUSY consistently in all cases when system suspend is aborted due to wakeup detection (Ruchi Kandoi). - support for automated device wakeup IRQ handling allowing drivers to make their PM support more starightforward (Tony Lindgren). - new tracepoints for suspend-to-idle tracing and rework of the prepare/complete callbacks tracing in the PM core (Todd E Brandt, Rafael J Wysocki). - wakeup sources framework enhancements (Jin Qian). - new macro for noirq system PM callbacks (Grygorii Strashko). - assorted cleanups related to system suspend (Rafael J Wysocki). - cpuidle core cleanups to make the code more efficient (Rafael J Wysocki). - powernv/pseries cpuidle driver update (Shilpasri G Bhat). - cpufreq core fixes related to CPU online/offline that should reduce the overhead of these operations quite a bit, unless the CPU in question is physically going away (Viresh Kumar, Saravana Kannan). - serialization of cpufreq governor callbacks to avoid race conditions in some cases (Viresh Kumar). - intel_pstate driver fixes and cleanups (Doug Smythies, Prarit Bhargava, Joe Konno). - cpufreq driver (arm_big_little, cpufreq-dt, qoriq) updates (Sudeep Holla, Felipe Balbi, Tang Yuantian). - assorted cleanups in cpufreq drivers and core (Shailendra Verma, Fabian Frederick, Wang Long). - new Device Tree bindings for representing Operating Performance Points (Viresh Kumar). - updates for the common clock operations support code in the PM core (Rajendra Nayak, Geert Uytterhoeven). - PM domains core code update (Geert Uytterhoeven). - Intel Knights Landing support for the RAPL (Running Average Power Limit) power capping driver (Dasaratharaman Chandramouli). - fixes related to the floor frequency setting on Atom SoCs in the RAPL power capping driver (Ajay Thomas). - runtime PM framework documentation update (Ben Dooks). - cpupower tool fix (Herton R Krzesinski)" * tag 'pm+acpi-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (194 commits) cpuidle: powernv/pseries: Auto-promotion of snooze to deeper idle state x86: Load __USER_DS into DS/ES after resume PM / OPP: Add binding for 'opp-suspend' PM / OPP: Allow multiple OPP tables to be passed via DT PM / OPP: Add new bindings to address shortcomings of existing bindings ACPI: Constify ACPI device IDs in documentation ACPI / enumeration: Document the rules regarding the PRP0001 device ID ACPI / video: Make acpi_video_unregister_backlight() private acpi-video-detect: Remove old API toshiba-acpi: Port to new backlight interface selection API thinkpad-acpi: Port to new backlight interface selection API sony-laptop: Port to new backlight interface selection API samsung-laptop: Port to new backlight interface selection API msi-wmi: Port to new backlight interface selection API msi-laptop: Port to new backlight interface selection API intel-oaktrail: Port to new backlight interface selection API ideapad-laptop: Port to new backlight interface selection API fujitsu-laptop: Port to new backlight interface selection API eeepc-laptop: Port to new backlight interface selection API dell-wmi: Port to new backlight interface selection API ...
| * PM / sleep: Make suspend-to-idle-specific code depend on CONFIG_SUSPENDRafael J. Wysocki2015-05-19
| | | | | | | | | | | | | | | | | | | | | | | | Since idle_should_freeze() is defined to always return 'false' for CONFIG_SUSPEND unset, all of the code depending on it in cpuidle_idle_call() is not necessary in that case. Make that code depend on CONFIG_SUSPEND too to avoid building it when it is not going to be used. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de>
* | nohz: Add tick_nohz_full_add_cpus_to() APIChris Metcalf2015-05-07
|/ | | | | | | | | | | | | | | | | | | | | | | This API is useful to modify a cpumask indicating some special nohz-type functionality so that the nohz cores are automatically added to that set. Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Jones <davej@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1429024675-18938-1-git-send-email-cmetcalf@ezchip.com Link: http://lkml.kernel.org/r/1430928266-24888-4-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* clockevents: Cleanup dead cpu explicitelyThomas Gleixner2015-04-03
| | | | | | | | | | | | | | | | | | | | clockevents_notify() is a leftover from the early design of the clockevents facility. It's really not a notification mechanism, it's a multiplex call. We are way better off to have explicit calls instead of this monstrosity. Split out the cleanup function for a dead cpu and invoke it directly from the cpu down code. Make it conditional on CPU_HOTPLUG as well. Temporary change, will be refined in the future. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [ Rebased, added clockevents_notify() removal ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1735025.raBZdQHM3m@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
* clockevents: Make tick handover explicitThomas Gleixner2015-04-03
| | | | | | | | | | | | | | | | | | | | | clockevents_notify() is a leftover from the early design of the clockevents facility. It's really not a notification mechanism, it's a multiplex call. We are way better off to have explicit calls instead of this monstrosity. Split out the tick_handover call and invoke it explicitely from the hotplug code. Temporary solution will be cleaned up in later patches. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [ Rebase ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1658173.RkEEILFiQZ@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
* clockevents: Provide explicit broadcast oneshot control functionsThomas Gleixner2015-04-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | clockevents_notify() is a leftover from the early design of the clockevents facility. It's really not a notification mechanism, it's a multiplex call. We are way better off to have explicit calls instead of this monstrosity. Split out the broadcast oneshot control into a separate function and provide inline helpers. Switch clockevents_notify() over. This will go away once all callers are converted. This also gets rid of the nested locking of clockevents_lock and broadcast_lock. The broadcast oneshot control functions do not require clockevents_lock. Only the managing functions (setup/shutdown/suspend/resume of the broadcast device require clockevents_lock. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Alexandre Courbot <gnurou@gmail.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Len Brown <lenb@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Warren <swarren@wwwdotorg.org> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Tony Lindgren <tony@atomide.com> Link: http://lkml.kernel.org/r/13000649.8qZuEDV0OA@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
* clockevents: Provide explicit broadcast control functionsThomas Gleixner2015-04-03
| | | | | | | | | | | | | | | | | | | | | | | | | | clockevents_notify() is a leftover from the early design of the clockevents facility. It's really not a notification mechanism, it's a multiplex call. We are way better off to have explicit calls instead of this monstrosity. Split out the broadcast control into a separate function and provide inline helpers. Switch clockevents_notify() over. This will go away once all callers are converted. This also gets rid of the nested locking of clockevents_lock and broadcast_lock. The broadcast control functions do not require clockevents_lock. Only the managing functions (setup/shutdown/suspend/resume of the broadcast device require clockevents_lock. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Len Brown <lenb@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tony Lindgren <tony@atomide.com> Link: http://lkml.kernel.org/r/8086559.ttsuS0n1Xr@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
* clockevents: Fix cpu_down() race for hrtimer based broadcastingPreeti U Murthy2015-04-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It was found when doing a hotplug stress test on POWER, that the machine either hit softlockups or rcu_sched stall warnings. The issue was traced to commit: 7cba160ad789 ("powernv/cpuidle: Redesign idle states management") which exposed the cpu_down() race with hrtimer based broadcast mode: 5d1638acb9f6 ("tick: Introduce hrtimer based broadcast") The race is the following: Assume CPU1 is the CPU which holds the hrtimer broadcasting duty before it is taken down. CPU0 CPU1 cpu_down() take_cpu_down() disable_interrupts() cpu_die() while (CPU1 != CPU_DEAD) { msleep(100); switch_to_idle(); stop_cpu_timer(); schedule_broadcast(); } tick_cleanup_cpu_dead() take_over_broadcast() So after CPU1 disabled interrupts it cannot handle the broadcast hrtimer anymore, so CPU0 will be stuck forever. Fix this by explicitly taking over broadcast duty before cpu_die(). This is a temporary workaround. What we really want is a callback in the clockevent device which allows us to do that from the dying CPU by pushing the hrtimer onto a different cpu. That might involve an IPI and is definitely more complex than this immediate fix. Changelog was picked up from: https://lkml.org/lkml/2015/2/16/213 Suggested-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Preeti U. Murthy <preeti@linux.vnet.ibm.com> Cc: linuxppc-dev@lists.ozlabs.org Cc: mpe@ellerman.id.au Cc: nicolas.pitre@linaro.org Cc: peterz@infradead.org Cc: rjw@rjwysocki.net Fixes: http://linuxppc.10917.n7.nabble.com/offlining-cpus-breakage-td88619.html Link: http://lkml.kernel.org/r/20150330092410.24979.59887.stgit@preeti.in.ibm.com [ Merged it to the latest timer tree, renamed the callback, tidied up the changelog. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
* arm/bL_switcher: Kill tick suspend hackeryThomas Gleixner2015-04-01
| | | | | | | | | | | | | | | | | | | | | Use the new tick_suspend/resume_local() and get rid of the homebrewn implementation of these in the ARM bL switcher. The check for the cpumask is completely pointless. There is no harm to suspend a per cpu tick device unconditionally. If that's a real issue then we fix it proper at the core level and not with some completely undocumented hacks in some random core code. Move the tick internals to the core code, now that this nuisance is gone. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [ rjw: Rebase, changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Link: http://lkml.kernel.org/r/1655112.Ws17YsMfN7@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
* tick/xen: Provide and use tick_suspend_local() and tick_resume_local()Thomas Gleixner2015-04-01
| | | | | | | | | | | | | | | | | | | | | | | | Xen calls on every cpu into tick_resume() which is just wrong. tick_resume() is for the syscore global suspend/resume invocation. What XEN really wants is a per cpu local resume function. Provide a tick_resume_local() function and use it in XEN. Also provide a complementary tick_suspend_local() and modify tick_unfreeze() and tick_freeze(), respectively, to use the new local tick resume/suspend functions. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [ Combined two patches, rebased, modified subject/changelog. ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1698741.eezk9tnXtG@vostro.rjw.lan [ Merged to latest timers/core. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
* clockevents: Make suspend/resume calls explicitThomas Gleixner2015-04-01
| | | | | | | | | | | | | | | | | | | | | clockevents_notify() is a leftover from the early design of the clockevents facility. It's really not a notification mechanism, it's a multiplex call. We are way better off to have explicit calls instead of this monstrosity. Split out the suspend/resume() calls and invoke them directly from the call sites. No locking required at this point because these calls happen with interrupts disabled and a single cpu online. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [ Rebased on top of 4.0-rc5. ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/713674030.jVm1qaHuPf@vostro.rjw.lan [ Rebased on top of latest timers/core. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
* tick: Move core only declarations and functions to coreThomas Gleixner2015-04-01
| | | | | | | | | | | | | | No point to expose everything to the world. People just believe such functions can be abused for whatever purposes. Sigh. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [ Rebased on top of 4.0-rc5 ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Nicolas Pitre <nico@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/28017337.VbCUc39Gme@vostro.rjw.lan [ Merged to latest timers/core ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
* PM / sleep: Make it possible to quiesce timers during suspend-to-idleRafael J. Wysocki2015-02-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The efficiency of suspend-to-idle depends on being able to keep CPUs in the deepest available idle states for as much time as possible. Ideally, they should only be brought out of idle by system wakeup interrupts. However, timer interrupts occurring periodically prevent that from happening and it is not practical to chase all of the "misbehaving" timers in a whack-a-mole fashion. A much more effective approach is to suspend the local ticks for all CPUs and the entire timekeeping along the lines of what is done during full suspend, which also helps to keep suspend-to-idle and full suspend reasonably similar. The idea is to suspend the local tick on each CPU executing cpuidle_enter_freeze() and to make the last of them suspend the entire timekeeping. That should prevent timer interrupts from triggering until an IO interrupt wakes up one of the CPUs. It needs to be done with interrupts disabled on all of the CPUs, though, because otherwise the suspended clocksource might be accessed by an interrupt handler which might lead to fatal consequences. Unfortunately, the existing ->enter callbacks provided by cpuidle drivers generally cannot be used for implementing that, because some of them re-enable interrupts temporarily and some idle entry methods cause interrupts to be re-enabled automatically on exit. Also some of these callbacks manipulate local clock event devices of the CPUs which really shouldn't be done after suspending their ticks. To overcome that difficulty, introduce a new cpuidle state callback, ->enter_freeze, that will be guaranteed (1) to keep interrupts disabled all the time (and return with interrupts disabled) and (2) not to touch the CPU timer devices. Modify cpuidle_enter_freeze() to look for the deepest available idle state with ->enter_freeze present and to make the CPU execute that callback with suspended tick (and the last of the online CPUs to execute it with suspended timekeeping). Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
* Merge branch 'for-linus' of ↵Linus Torvalds2014-10-14
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Martin Schwidefsky: "This patch set contains the main portion of the changes for 3.18 in regard to the s390 architecture. It is a bit bigger than usual, mainly because of a new driver and the vector extension patches. The interesting bits are: - Quite a bit of work on the tracing front. Uprobes is enabled and the ftrace code is reworked to get some of the lost performance back if CONFIG_FTRACE is enabled. - To improve boot time with CONFIG_DEBIG_PAGEALLOC, support for the IPTE range facility is added. - The rwlock code is re-factored to improve writer fairness and to be able to use the interlocked-access instructions. - The kernel part for the support of the vector extension is added. - The device driver to access the CD/DVD on the HMC is added, this will hopefully come in handy to improve the installation process. - Add support for control-unit initiated reconfiguration. - The crypto device driver is enhanced to enable the additional AP domains and to allow the new crypto hardware to be used. - Bug fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (39 commits) s390/ftrace: simplify enabling/disabling of ftrace_graph_caller s390/ftrace: remove 31 bit ftrace support s390/kdump: add support for vector extension s390/disassembler: add vector instructions s390: add support for vector extension s390/zcrypt: Toleration of new crypto hardware s390/idle: consolidate idle functions and definitions s390/nohz: use a per-cpu flag for arch_needs_cpu s390/vtime: do not reset idle data on CPU hotplug s390/dasd: add support for control unit initiated reconfiguration s390/dasd: fix infinite loop during format s390/mm: make use of ipte range facility s390/setup: correct 4-level kernel page table detection s390/topology: call set_sched_topology early s390/uprobes: architecture backend for uprobes s390/uprobes: common library for kprobes and uprobes s390/rwlock: use the interlocked-access facility 1 instructions s390/rwlock: improve writer fairness s390/rwlock: remove interrupt-enabling rwlock variant. s390/mm: remove change bit override support ...
| * s390/nohz: use a per-cpu flag for arch_needs_cpuMartin Schwidefsky2014-10-09
| | | | | | | | | | | | | | | | Move the nohz_delay bit from the s390_idle data structure to the per-cpu flags. Clear the nohz delay flag in __cpu_disable and remove the cpu hotplug notifier that used to do this. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* | nohz: Move nohz full init call to tick initFrederic Weisbecker2014-09-13
|/ | | | | | | | | | | | | | | | | | This way we unbloat a bit main.c and more importantly we initialize nohz full after init_IRQ(). This dependency will be needed in further patches because nohz full needs irq work to raise its own IRQ. Information about the support for this ability on ARM64 is obtained on init_IRQ() which initialize the pointer to __smp_call_function. Since tick_init() is called right after init_IRQ(), this is a good place to call tick_nohz_init() and prepare for that dependency. Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
* nohz: Restore NMI safe local irq work for local nohz kickFrederic Weisbecker2014-09-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The local nohz kick is currently used by perf which needs it to be NMI-safe. Recent commit though (7d1311b93e58ed55f3a31cc8f94c4b8fe988a2b9) changed its implementation to fire the local kick using the remote kick API. It was convenient to make the code more generic but the remote kick isn't NMI-safe. As a result: WARNING: CPU: 3 PID: 18062 at kernel/irq_work.c:72 irq_work_queue_on+0x11e/0x140() CPU: 3 PID: 18062 Comm: trinity-subchil Not tainted 3.16.0+ #34 0000000000000009 00000000903774d1 ffff880244e06c00 ffffffff9a7f1e37 0000000000000000 ffff880244e06c38 ffffffff9a0791dd ffff880244fce180 0000000000000003 ffff880244e06d58 ffff880244e06ef8 0000000000000000 Call Trace: <NMI> [<ffffffff9a7f1e37>] dump_stack+0x4e/0x7a [<ffffffff9a0791dd>] warn_slowpath_common+0x7d/0xa0 [<ffffffff9a07930a>] warn_slowpath_null+0x1a/0x20 [<ffffffff9a17ca1e>] irq_work_queue_on+0x11e/0x140 [<ffffffff9a10a2c7>] tick_nohz_full_kick_cpu+0x57/0x90 [<ffffffff9a186cd5>] __perf_event_overflow+0x275/0x350 [<ffffffff9a184f80>] ? perf_event_task_disable+0xa0/0xa0 [<ffffffff9a01a4cf>] ? x86_perf_event_set_period+0xbf/0x150 [<ffffffff9a187934>] perf_event_overflow+0x14/0x20 [<ffffffff9a020386>] intel_pmu_handle_irq+0x206/0x410 [<ffffffff9a0b54d3>] ? arch_vtime_task_switch+0x63/0x130 [<ffffffff9a01937b>] perf_event_nmi_handler+0x2b/0x50 [<ffffffff9a007b72>] nmi_handle+0xd2/0x390 [<ffffffff9a007aa5>] ? nmi_handle+0x5/0x390 [<ffffffff9a0d131b>] ? lock_release+0xab/0x330 [<ffffffff9a008062>] default_do_nmi+0x72/0x1c0 [<ffffffff9a0c925f>] ? cpuacct_account_field+0xcf/0x200 [<ffffffff9a008268>] do_nmi+0xb8/0x100 Lets fix this by restoring the use of local irq work for the nohz local kick. Reported-by: Catalin Iacob <iacobcatalin@gmail.com> Reported-and-tested-by: Dave Jones <davej@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
* Merge branch 'sched-core-for-linus' of ↵Linus Torvalds2014-08-04
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: - Move the nohz kick code out of the scheduler tick to a dedicated IPI, from Frederic Weisbecker. This necessiated quite some background infrastructure rework, including: * Clean up some irq-work internals * Implement remote irq-work * Implement nohz kick on top of remote irq-work * Move full dynticks timer enqueue notification to new kick * Move multi-task notification to new kick * Remove unecessary barriers on multi-task notification - Remove proliferation of wait_on_bit() action functions and allow wait_on_bit_action() functions to support a timeout. (Neil Brown) - Another round of sched/numa improvements, cleanups and fixes. (Rik van Riel) - Implement fast idling of CPUs when the system is partially loaded, for better scalability. (Tim Chen) - Restructure and fix the CPU hotplug handling code that may leave cfs_rq and rt_rq's throttled when tasks are migrated away from a dead cpu. (Kirill Tkhai) - Robustify the sched topology setup code. (Peterz Zijlstra) - Improve sched_feat() handling wrt. static_keys (Jason Baron) - Misc fixes. * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits) sched/fair: Fix 'make xmldocs' warning caused by missing description sched: Use macro for magic number of -1 for setparam sched: Robustify topology setup sched: Fix sched_setparam() policy == -1 logic sched: Allow wait_on_bit_action() functions to support a timeout sched: Remove proliferation of wait_on_bit() action functions sched/numa: Revert "Use effective_load() to balance NUMA loads" sched: Fix static_key race with sched_feat() sched: Remove extra static_key*() function indirection sched/rt: Fix replenish_dl_entity() comments to match the current upstream code sched: Transform resched_task() into resched_curr() sched/deadline: Kill task_struct->pi_top_task sched: Rework check_for_tasks() sched/rt: Enqueue just unthrottled rt_rq back on the stack in __disable_runtime() sched/fair: Disable runtime_enabled on dying rq sched/numa: Change scan period code to match intent sched/numa: Rework best node setting in task_numa_migrate() sched/numa: Examine a task move when examining a task swap sched/numa: Simplify task_numa_compare() sched/numa: Use effective_load() to balance NUMA loads ...
| * nohz: Support nohz full remote kickFrederic Weisbecker2014-06-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remotely kicking a full nohz CPU in order to make it re-evaluate its next tick is currently implemented using the scheduler IPI. However this bloats a scheduler fast path with an off-topic feature. The scheduler tick was abused here for its cool "callable anywhere/anytime" properties. But now that the irq work subsystem can queue remote callbacks, it's a perfect fit to safely queue IPIs when interrupts are disabled without worrying about concurrent callers. So lets implement remote kick on top of irq work. This is going to be used when a new event requires the next tick to be recalculated: more than 1 task competing on the CPU, timer armed, ... Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
* | rcu: Bind grace-period kthreads to non-NO_HZ_FULL CPUsPaul E. McKenney2014-07-09
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | Binding the grace-period kthreads to the timekeeping CPU resulted in significant performance decreases for some workloads. For more detail, see: https://lkml.org/lkml/2014/6/3/395 for benchmark numbers https://lkml.org/lkml/2014/6/4/218 for CPU statistics It turns out that it is necessary to bind the grace-period kthreads to the timekeeping CPU only when all but CPU 0 is a nohz_full CPU on the one hand or if CONFIG_NO_HZ_FULL_SYSIDLE=y on the other. In other cases, it suffices to bind the grace-period kthreads to the set of non-nohz_full CPUs. This commit therefore creates a tick_nohz_not_full_mask that is the complement of tick_nohz_full_mask, and then binds the grace-period kthread to the set of CPUs indicated by this new mask, which covers the CONFIG_NO_HZ_FULL_SYSIDLE=n case. The CONFIG_NO_HZ_FULL_SYSIDLE=y case still binds the grace-period kthreads to the timekeeping CPU. This commit also includes the tick_nohz_full_enabled() check suggested by Frederic Weisbecker. Reported-by: Jet Chen <jet.chen@intel.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> [ paulmck: Created housekeeping_affine() and housekeeping_mask per fweisbec feedback. ]
* tick: Rename tick_check_idle() to tick_irq_enter()Frederic Weisbecker2014-01-15
| | | | | | | | | | | | | | | | | | | | | | | | This makes the code more symetric against the existing tick functions called on irq exit: tick_irq_exit() and tick_nohz_irq_exit(). These function are also symetric as they mirror each other's action: we start to account idle time on irq exit and we stop this accounting on irq entry. Also the tick is stopped on irq exit and timekeeping catches up with the tickless time elapsed until we reach irq entry. This rename was suggested by Peter Zijlstra a long while ago but it got forgotten in the mass. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Alex Shi <alex.shi@linaro.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Kevin Hilman <khilman@linaro.org> Link: http://lkml.kernel.org/r/1387320692-28460-2-git-send-email-fweisbec@gmail.com Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
* context_tracking: Wrap static key check into more intuitive function nameFrederic Weisbecker2013-12-02
| | | | | | | | | | | | Use a function with a meaningful name to check the global context tracking state. static_key_false() is a bit confusing for reviewers. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org>
* nohz: Convert a few places to use local per cpu accessesFrederic Weisbecker2013-12-02
| | | | | | | | | | | | | | | | | | A few functions use remote per CPU access APIs when they deal with local values. Just do the right conversion to improve performance, code readability and debug checks. While at it, lets extend some of these function names with *_this_cpu() suffix in order to display their purpose more clearly. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org>
* Merge branch 'timers/nohz-v3' of ↵Ingo Molnar2013-08-14
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into timers/nohz Pull nohz improvements from Frederic Weisbecker: " It mostly contains fixes and full dynticks off-case optimizations. I believe that distros want to enable this feature so it seems important to optimize the case where the "nohz_full=" parameter is empty. ie: I'm trying to remove any performance regression that comes with NO_HZ_FULL=y when the feature is not used. This patchset improves the current situation a lot (off-case appears to be around 11% faster with hackbench, although I guess it may vary depending on the configuration but it should be significantly faster in any case) now there is still some work to do: I can still observe a remaining loss of 1.6% throughput seen with hackbench compared to CONFIG_NO_HZ_FULL=n. " Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * nohz: Optimize full dynticks's sched hooks with static keysFrederic Weisbecker2013-08-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Scheduler IPIs and task context switches are serious fast path. Let's try to hide as much as we can the impact of full dynticks APIs' off case that are called on these sites through the use of static keys. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Kevin Hilman <khilman@linaro.org>
| * nohz: Optimize full dynticks state checks with static keysFrederic Weisbecker2013-08-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These APIs are frequenctly accessed and priority is given to optimize the full dynticks off-case in order to let distros enable this feature without suffering from significant performance regressions. Let's inline these APIs and optimize them with static keys. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Kevin Hilman <khilman@linaro.org>
* | Revert "cpuidle: Quickly notice prediction failure for repeat mode"Rafael J. Wysocki2013-07-29
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Revert commit 69a37bea (cpuidle: Quickly notice prediction failure for repeat mode), because it has been identified as the source of a significant performance regression in v3.8 and later as explained by Jeremy Eder: We believe we've identified a particular commit to the cpuidle code that seems to be impacting performance of variety of workloads. The simplest way to reproduce is using netperf TCP_RR test, so we're using that, on a pair of Sandy Bridge based servers. We also have data from a large database setup where performance is also measurably/positively impacted, though that test data isn't easily share-able. Included below are test results from 3 test kernels: kernel reverts ----------------------------------------------------------- 1) vanilla upstream (no reverts) 2) perfteam2 reverts e11538d1f03914eb92af5a1a378375c05ae8520c 3) test reverts 69a37beabf1f0a6705c08e879bdd5d82ff6486c4 e11538d1f03914eb92af5a1a378375c05ae8520c In summary, netperf TCP_RR numbers improve by approximately 4% after reverting 69a37beabf1f0a6705c08e879bdd5d82ff6486c4. When 69a37beabf1f0a6705c08e879bdd5d82ff6486c4 is included, C0 residency never seems to get above 40%. Taking that patch out gets C0 near 100% quite often, and performance increases. The below data are histograms representing the %c0 residency @ 1-second sample rates (using turbostat), while under netperf test. - If you look at the first 4 histograms, you can see %c0 residency almost entirely in the 30,40% bin. - The last pair, which reverts 69a37beabf1f0a6705c08e879bdd5d82ff6486c4, shows %c0 in the 80,90,100% bins. Below each kernel name are netperf TCP_RR trans/s numbers for the particular kernel that can be disclosed publicly, comparing the 3 test kernels. We ran a 4th test with the vanilla kernel where we've also set /dev/cpu_dma_latency=0 to show overall impact boosting single-threaded TCP_RR performance over 11% above baseline. 3.10-rc2 vanilla RX + c0 lock (/dev/cpu_dma_latency=0): TCP_RR trans/s 54323.78 ----------------------------------------------------------- 3.10-rc2 vanilla RX (no reverts) TCP_RR trans/s 48192.47 Receiver %c0 0.0000 - 10.0000 [ 1]: * 10.0000 - 20.0000 [ 0]: 20.0000 - 30.0000 [ 0]: 30.0000 - 40.0000 [ 59]: *********************************************************** 40.0000 - 50.0000 [ 1]: * 50.0000 - 60.0000 [ 0]: 60.0000 - 70.0000 [ 0]: 70.0000 - 80.0000 [ 0]: 80.0000 - 90.0000 [ 0]: 90.0000 - 100.0000 [ 0]: Sender %c0 0.0000 - 10.0000 [ 1]: * 10.0000 - 20.0000 [ 0]: 20.0000 - 30.0000 [ 0]: 30.0000 - 40.0000 [ 11]: *********** 40.0000 - 50.0000 [ 49]: ************************************************* 50.0000 - 60.0000 [ 0]: 60.0000 - 70.0000 [ 0]: 70.0000 - 80.0000 [ 0]: 80.0000 - 90.0000 [ 0]: 90.0000 - 100.0000 [ 0]: ----------------------------------------------------------- 3.10-rc2 perfteam2 RX (reverts commit e11538d1f03914eb92af5a1a378375c05ae8520c) TCP_RR trans/s 49698.69 Receiver %c0 0.0000 - 10.0000 [ 1]: * 10.0000 - 20.0000 [ 1]: * 20.0000 - 30.0000 [ 0]: 30.0000 - 40.0000 [ 59]: *********************************************************** 40.0000 - 50.0000 [ 0]: 50.0000 - 60.0000 [ 0]: 60.0000 - 70.0000 [ 0]: 70.0000 - 80.0000 [ 0]: 80.0000 - 90.0000 [ 0]: 90.0000 - 100.0000 [ 0]: Sender %c0 0.0000 - 10.0000 [ 1]: * 10.0000 - 20.0000 [ 0]: 20.0000 - 30.0000 [ 0]: 30.0000 - 40.0000 [ 2]: ** 40.0000 - 50.0000 [ 58]: ********************************************************** 50.0000 - 60.0000 [ 0]: 60.0000 - 70.0000 [ 0]: 70.0000 - 80.0000 [ 0]: 80.0000 - 90.0000 [ 0]: 90.0000 - 100.0000 [ 0]: ----------------------------------------------------------- 3.10-rc2 test RX (reverts 69a37beabf1f0a6705c08e879bdd5d82ff6486c4 and e11538d1f03914eb92af5a1a378375c05ae8520c) TCP_RR trans/s 47766.95 Receiver %c0 0.0000 - 10.0000 [ 1]: * 10.0000 - 20.0000 [ 1]: * 20.0000 - 30.0000 [ 0]: 30.0000 - 40.0000 [ 27]: *************************** 40.0000 - 50.0000 [ 2]: ** 50.0000 - 60.0000 [ 0]: 60.0000 - 70.0000 [ 2]: ** 70.0000 - 80.0000 [ 0]: 80.0000 - 90.0000 [ 0]: 90.0000 - 100.0000 [ 28]: **************************** Sender: 0.0000 - 10.0000 [ 1]: * 10.0000 - 20.0000 [ 0]: 20.0000 - 30.0000 [ 0]: 30.0000 - 40.0000 [ 11]: *********** 40.0000 - 50.0000 [ 0]: 50.0000 - 60.0000 [ 1]: * 60.0000 - 70.0000 [ 0]: 70.0000 - 80.0000 [ 3]: *** 80.0000 - 90.0000 [ 7]: ******* 90.0000 - 100.0000 [ 38]: ************************************** These results demonstrate gaining back the tendency of the CPU to stay in more responsive, performant C-states (and thus yield measurably better performance), by reverting commit 69a37beabf1f0a6705c08e879bdd5d82ff6486c4. Requested-by: Jeremy Eder <jeder@redhat.com> Tested-by: Len Brown <len.brown@intel.com> Cc: 3.8+ <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* nohz: Re-evaluate the tick for the new task after a context switchFrederic Weisbecker2013-04-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | When a task is scheduled in, it may have some properties of its own that could make the CPU reconsider the need for the tick: posix cpu timers, perf events, ... So notify the full dynticks subsystem when a task gets scheduled in and re-check the tick dependency at this stage. This is done through a self IPI to avoid messing up with any current lock scenario. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
* nohz: Re-evaluate the tick from the scheduler IPIFrederic Weisbecker2013-04-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The scheduler IPI is used by the scheduler to kick full dynticks CPUs asynchronously when more than one task are running or when a new timer list timer is enqueued. This way the destination CPU can decide to restart the tick to handle this new situation. Now let's call that kick in the scheduler IPI. (Reusing the scheduler IPI rather than implementing a new IPI was suggested by Peter Zijlstra a while ago) Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
* Merge branch 'timers/nohz-posix-timers-v2' of ↵Ingo Molnar2013-04-21
|\ | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into timers/nohz Pull posix cpu timers handling on full dynticks from Frederic Weisbecker. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * nohz: New APIs to re-evaluate the tick on full dynticks CPUsFrederic Weisbecker2013-04-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provide two new helpers in order to notify the full dynticks CPUs about some internal system changes against which they may reconsider the state of their tick. Some practical examples include: posix cpu timers, perf tick and sched clock tick. For now the notifying handler, implemented through IPIs, is a stub that will be implemented when we get the tick stop/restart infrastructure in. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
* | nohz: Ensure full dynticks CPUs are RCU nocbsFrederic Weisbecker2013-04-19
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We need full dynticks CPU to also be RCU nocb so that we don't have to keep the tick to handle RCU callbacks. Make sure the range passed to nohz_full= boot parameter is a subset of rcu_nocbs= The CPUs that fail to meet this requirement will be excluded from the nohz_full range. This is checked early in boot time, before any CPU has the opportunity to stop its tick. Suggested-by: Steven Rostedt <rostedt@goodmis.org> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
* nohz: Switch from "extended nohz" to "full nohz" based namingFrederic Weisbecker2013-04-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | "Extended nohz" was used as a naming base for the full dynticks API and Kconfig symbols. It reflects the fact the system tries to stop the tick in more places than just idle. But that "extended" name is a bit opaque and vague. Rename it to "full" makes it clearer what the system tries to do under this config: try to shutdown the tick anytime it can. The various constraints that prevent that to happen shouldn't be considered as fundamental properties of this feature but rather technical issues that may be solved in the future. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
* nohz: Rename CONFIG_NO_HZ to CONFIG_NO_HZ_COMMONFrederic Weisbecker2013-04-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We are planning to convert the dynticks Kconfig options layout into a choice menu. The user must be able to easily pick any of the following implementations: constant periodic tick, idle dynticks, full dynticks. As this implies a mutual exclusion, the two dynticks implementions need to converge on the selection of a common Kconfig option in order to ease the sharing of a common infrastructure. It would thus seem pretty natural to reuse CONFIG_NO_HZ to that end. It already implements all the idle dynticks code and the full dynticks depends on all that code for now. So ideally the choice menu would propose CONFIG_NO_HZ_IDLE and CONFIG_NO_HZ_EXTENDED then both would select CONFIG_NO_HZ. On the other hand we want to stay backward compatible: if CONFIG_NO_HZ is set in an older config file, we want to enable CONFIG_NO_HZ_IDLE by default. But we can't afford both at the same time or we run into a circular dependency: 1) CONFIG_NO_HZ_IDLE and CONFIG_NO_HZ_EXTENDED both select CONFIG_NO_HZ 2) If CONFIG_NO_HZ is set, we default to CONFIG_NO_HZ_IDLE We might be able to support that from Kconfig/Kbuild but it may not be wise to introduce such a confusing behaviour. So to solve this, create a new CONFIG_NO_HZ_COMMON option which gathers the common code between idle and full dynticks (that common code for now is simply the idle dynticks code) and select it from their referring Kconfig. Then we'll later create CONFIG_NO_HZ_IDLE and map CONFIG_NO_HZ to it for backward compatibility. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
* nohz: Basic full dynticks interfaceFrederic Weisbecker2013-03-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For extreme usecases such as Real Time or HPC, having the ability to shutdown the tick when a single task runs on a CPU is a desired feature: * Reducing the amount of interrupts improves throughput for CPU-bound tasks. The CPU is less distracted from its real job, from an execution time and from the cache point of views. * This also improve latency response as we have less critical sections. Start with introducing a very simple interface to define full dynticks CPU: use a boot time option defined cpumask through the "nohz_extended=" kernel parameter. CPUs that are part of this range will have their tick shutdown whenever possible: provided they run a single task and they don't do kernel activity that require the periodic tick. These details will be later documented in Documentation/* An online CPU must be kept outside this range to handle the timekeeping. Suggested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
* Merge branch 'nohz/printk-v8' into irq/coreFrederic Weisbecker2013-02-05
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: kernel/irq_work.c Add support for printk in full dynticks CPU. * Don't stop tick with irq works pending. This fix is generally useful and concerns archs that can't raise self IPIs. * Flush irq works before CPU offlining. * Introduce "lazy" irq works that can wait for the next tick to be executed, unless it's stopped. * Implement klogd wake up using irq work. This removes the ad-hoc printk_tick()/printk_needs_cpu() hooks and make it working even in dynticks mode. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
| * nohz: Add API to check tick stateFrederic Weisbecker2012-11-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | We need some quick way to check if the CPU has stopped its tick. This will be useful to implement the printk tick using the irq work subsystem. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
* | cpuidle: Quickly notice prediction failure for repeat modeYouquan Song2012-11-15
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The prediction for future is difficult and when the cpuidle governor prediction fails and govenor possibly choose the shallower C-state than it should. How to quickly notice and find the failure becomes important for power saving. cpuidle menu governor has a method to predict the repeat pattern if there are 8 C-states residency which are continuous and the same or very close, so it will predict the next C-states residency will keep same residency time. There is a real case that turbostat utility (tools/power/x86/turbostat) at kernel 3.3 or early. turbostat utility will read 10 registers one by one at Sandybridge, so it will generate 10 IPIs to wake up idle CPUs. So cpuidle menu governor will predict it is repeat mode and there is another IPI wake up idle CPU soon, so it keeps idle CPU stay at C1 state even though CPU is totally idle. However, in the turbostat, following 10 registers reading is sleep 5 seconds by default, so the idle CPU will keep at C1 for a long time though it is idle until break event occurs. In a idle Sandybridge system, run "./turbostat -v", we will notice that deep C-state dangles between "70% ~ 99%". After patched the kernel, we will notice deep C-state stays at >99.98%. In the patch, a timer is added when menu governor detects a repeat mode and choose a shallow C-state. The timer is set to a time out value that greater than predicted time, and we conclude repeat mode prediction failure if timer is triggered. When repeat mode happens as expected, the timer is not triggered and CPU waken up from C-states and it will cancel the timer initiatively. When repeat mode does not happen, the timer will be time out and menu governor will quickly notice that the repeat mode prediction fails and then re-evaluates deeper C-states possibility. Below is another case which will clearly show the patch much benefit: #include <stdlib.h> #include <stdio.h> #include <unistd.h> #include <signal.h> #include <sys/time.h> #include <time.h> #include <pthread.h> volatile int * shutdown; volatile long * count; int delay = 20; int loop = 8; void usage(void) { fprintf(stderr, "Usage: idle_predict [options]\n" " --help -h Print this help\n" " --thread -n Thread number\n" " --loop -l Loop times in shallow Cstate\n" " --delay -t Sleep time (uS)in shallow Cstate\n"); } void *simple_loop() { int idle_num = 1; while (!(*shutdown)) { *count = *count + 1; if (idle_num % loop) usleep(delay); else { /* sleep 1 second */ usleep(1000000); idle_num = 0; } idle_num++; } } static void sighand(int sig) { *shutdown = 1; } int main(int argc, char *argv[]) { sigset_t sigset; int signum = SIGALRM; int i, c, er = 0, thread_num = 8; pthread_t pt[1024]; static char optstr[] = "n:l:t:h:"; while ((c = getopt(argc, argv, optstr)) != EOF) switch (c) { case 'n': thread_num = atoi(optarg); break; case 'l': loop = atoi(optarg); break; case 't': delay = atoi(optarg); break; case 'h': default: usage(); exit(1); } printf("thread=%d,loop=%d,delay=%d\n",thread_num,loop,delay); count = malloc(sizeof(long)); shutdown = malloc(sizeof(int)); *count = 0; *shutdown = 0; sigemptyset(&sigset); sigaddset(&sigset, signum); sigprocmask (SIG_BLOCK, &sigset, NULL); signal(SIGINT, sighand); signal(SIGTERM, sighand); for(i = 0; i < thread_num ; i++) pthread_create(&pt[i], NULL, simple_loop, NULL); for (i = 0; i < thread_num; i++) pthread_join(pt[i], NULL); exit(0); } Get powertop V2 from git://github.com/fenrus75/powertop, build powertop. After build the above test application, then run it. Test plaform can be Intel Sandybridge or other recent platforms. #./idle_predict -l 10 & #./powertop We will find that deep C-state will dangle between 40%~100% and much time spent on C1 state. It is because menu governor wrongly predict that repeat mode is kept, so it will choose the C1 shallow C-state even though it has chance to sleep 1 second in deep C-state. While after patched the kernel, we find that deep C-state will keep >99.6%. Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Youquan Song <youquan.song@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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