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authorSrinivasarao P <spathi@codeaurora.org>2018-01-09 16:05:02 +0530
committerSrinivasarao P <spathi@codeaurora.org>2018-01-18 12:49:58 +0530
commit2d309c994df3624f59114edea6c03dd7cf3f334d (patch)
treedc435837f02d89571f8139262e796e46fa91f228 /kernel/sched/deadline.c
parentdd4f1e35fa5f5a452d34e1fcc681472f2011f93d (diff)
parent79f138ac8c951ea1a06df9c869d16cc983613ac9 (diff)
Merge android-4.4.107 (79f138a) into msm-4.4
* refs/heads/tmp-79f138a Linux 4.4.107 ath9k: fix tx99 potential info leak IB/ipoib: Grab rtnl lock on heavy flush when calling ndo_open/stop RDMA/cma: Avoid triggering undefined behavior macvlan: Only deliver one copy of the frame to the macvlan interface udf: Avoid overflow when session starts at large offset scsi: bfa: integer overflow in debugfs scsi: sd: change allow_restart to bool in sysfs interface scsi: sd: change manage_start_stop to bool in sysfs interface vt6655: Fix a possible sleep-in-atomic bug in vt6655_suspend scsi: scsi_devinfo: Add REPORTLUN2 to EMC SYMMETRIX blacklist entry raid5: Set R5_Expanded on parity devices as well as data. pinctrl: adi2: Fix Kconfig build problem usb: musb: da8xx: fix babble condition handling tty fix oops when rmmod 8250 powerpc/perf/hv-24x7: Fix incorrect comparison in memord scsi: hpsa: destroy sas transport properties before scsi_host scsi: hpsa: cleanup sas_phy structures in sysfs when unloading PCI: Detach driver before procfs & sysfs teardown on device remove xfs: fix incorrect extent state in xfs_bmap_add_extent_unwritten_real xfs: fix log block underflow during recovery cycle verification l2tp: cleanup l2tp_tunnel_delete calls bcache: fix wrong cache_misses statistics bcache: explicitly destroy mutex while exiting GFS2: Take inode off order_write list when setting jdata flag thermal/drivers/step_wise: Fix temperature regulation misbehavior ppp: Destroy the mutex when cleanup clk: tegra: Fix cclk_lp divisor register clk: imx6: refine hdmi_isfr's parent to make HDMI work on i.MX6 SoCs w/o VPU clk: mediatek: add the option for determining PLL source clock mm: Handle 0 flags in _calc_vm_trans() macro crypto: tcrypt - fix buffer lengths in test_aead_speed() arm-ccn: perf: Prevent module unload while PMU is in use target/file: Do not return error for UNMAP if length is zero target:fix condition return in core_pr_dump_initiator_port() iscsi-target: fix memory leak in lio_target_tiqn_addtpg() target/iscsi: Fix a race condition in iscsit_add_reject_from_cmd() powerpc/ipic: Fix status get and status clear powerpc/opal: Fix EBUSY bug in acquiring tokens netfilter: ipvs: Fix inappropriate output of procfs powerpc/powernv/cpufreq: Fix the frequency read by /proc/cpuinfo PCI/PME: Handle invalid data when reading Root Status dmaengine: ti-dma-crossbar: Correct am335x/am43xx mux value type rtc: pcf8563: fix output clock rate video: fbdev: au1200fb: Return an error code if a memory allocation fails video: fbdev: au1200fb: Release some resources if a memory allocation fails video: udlfb: Fix read EDID timeout fbdev: controlfb: Add missing modes to fix out of bounds access sfc: don't warn on successful change of MAC target: fix race during implicit transition work flushes target: fix ALUA transition timeout handling target: Use system workqueue for ALUA transitions btrfs: add missing memset while reading compressed inline extents NFSv4.1 respect server's max size in CREATE_SESSION efi/esrt: Cleanup bad memory map log messages perf symbols: Fix symbols__fixup_end heuristic for corner cases net/mlx4_core: Avoid delays during VF driver device shutdown afs: Fix afs_kill_pages() afs: Fix page leak in afs_write_begin() afs: Populate and use client modification time afs: Fix the maths in afs_fs_store_data() afs: Prevent callback expiry timer overflow afs: Migrate vlocation fields to 64-bit afs: Flush outstanding writes when an fd is closed afs: Adjust mode bits processing afs: Populate group ID from vnode status afs: Fix missing put_page() drm/radeon: reinstate oland workaround for sclk mmc: mediatek: Fixed bug where clock frequency could be set wrong sched/deadline: Use deadline instead of period when calculating overflow sched/deadline: Throttle a constrained deadline task activated after the deadline sched/deadline: Make sure the replenishment timer fires in the next period drm/radeon/si: add dpm quirk for Oland fjes: Fix wrong netdevice feature flags scsi: hpsa: limit outstanding rescans scsi: hpsa: update check for logical volume status openrisc: fix issue handling 8 byte get_user calls intel_th: pci: Add Gemini Lake support mlxsw: reg: Fix SPVMLR max record count mlxsw: reg: Fix SPVM max record count net: Resend IGMP memberships upon peer notification. dmaengine: Fix array index out of bounds warning in __get_unmap_pool() net: wimax/i2400m: fix NULL-deref at probe writeback: fix memory leak in wb_queue_work() netfilter: bridge: honor frag_max_size when refragmenting drm/omap: fix dmabuf mmap for dma_alloc'ed buffers Input: i8042 - add TUXEDO BU1406 (N24_25BU) to the nomux list NFSD: fix nfsd_reset_versions for NFSv4. NFSD: fix nfsd_minorversion(.., NFSD_AVAIL) net: bcmgenet: Power up the internal PHY before probing the MII net: bcmgenet: power down internal phy if open or resume fails net: bcmgenet: reserved phy revisions must be checked first net: bcmgenet: correct MIB access of UniMAC RUNT counters net: bcmgenet: correct the RBUF_OVFL_CNT and RBUF_ERR_CNT MIB values net: initialize msg.msg_flags in recvfrom userfaultfd: selftest: vm: allow to build in vm/ directory userfaultfd: shmem: __do_fault requires VM_FAULT_NOPAGE md-cluster: free md_cluster_info if node leave cluster usb: phy: isp1301: Add OF device ID table mac80211: Fix addition of mesh configuration element KEYS: add missing permission check for request_key() destination ext4: fix crash when a directory's i_size is too small ext4: fix fdatasync(2) after fallocate(2) operation dmaengine: dmatest: move callback wait queue to thread context sched/rt: Do not pull from current CPU if only one CPU to pull xhci: Don't add a virt_dev to the devs array before it's fully allocated Bluetooth: btusb: driver to enable the usb-wakeup feature ceph: drop negative child dentries before try pruning inode's alias usbip: fix stub_send_ret_submit() vulnerability to null transfer_buffer USB: core: prevent malicious bNumInterfaces overflow USB: uas and storage: Add US_FL_BROKEN_FUA for another JMicron JMS567 ID tracing: Allocate mask_str buffer dynamically autofs: fix careless error in recent commit crypto: salsa20 - fix blkcipher_walk API usage crypto: hmac - require that the underlying hash algorithm is unkeyed UPSTREAM: arm64: setup: introduce kaslr_offset() UPSTREAM: kcov: fix comparison callback signature UPSTREAM: kcov: support comparison operands collection UPSTREAM: kcov: remove pointless current != NULL check UPSTREAM: kcov: support compat processes UPSTREAM: kcov: simplify interrupt check UPSTREAM: kcov: make kcov work properly with KASLR enabled UPSTREAM: kcov: add more missing includes UPSTREAM: kcov: add missing #include <linux/sched.h> UPSTREAM: kcov: properly check if we are in an interrupt UPSTREAM: kcov: don't profile branches in kcov UPSTREAM: kcov: don't trace the code coverage code BACKPORT: kernel: add kcov code coverage Conflicts: Makefile mm/kasan/Makefile scripts/Makefile.lib Change-Id: Ic19953706ea2e700621b0ba94d1c90bbffa4f471 Signed-off-by: Srinivasarao P <spathi@codeaurora.org>
Diffstat (limited to 'kernel/sched/deadline.c')
-rw-r--r--kernel/sched/deadline.c62
1 files changed, 56 insertions, 6 deletions
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index bb22bcf499f8..e7b377d91043 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -463,13 +463,13 @@ static void replenish_dl_entity(struct sched_dl_entity *dl_se,
*
* This function returns true if:
*
- * runtime / (deadline - t) > dl_runtime / dl_period ,
+ * runtime / (deadline - t) > dl_runtime / dl_deadline ,
*
* IOW we can't recycle current parameters.
*
- * Notice that the bandwidth check is done against the period. For
+ * Notice that the bandwidth check is done against the deadline. For
* task with deadline equal to period this is the same of using
- * dl_deadline instead of dl_period in the equation above.
+ * dl_period instead of dl_deadline in the equation above.
*/
static bool dl_entity_overflow(struct sched_dl_entity *dl_se,
struct sched_dl_entity *pi_se, u64 t)
@@ -494,7 +494,7 @@ static bool dl_entity_overflow(struct sched_dl_entity *dl_se,
* of anything below microseconds resolution is actually fiction
* (but still we want to give the user that illusion >;).
*/
- left = (pi_se->dl_period >> DL_SCALE) * (dl_se->runtime >> DL_SCALE);
+ left = (pi_se->dl_deadline >> DL_SCALE) * (dl_se->runtime >> DL_SCALE);
right = ((dl_se->deadline - t) >> DL_SCALE) *
(pi_se->dl_runtime >> DL_SCALE);
@@ -535,10 +535,15 @@ static void update_dl_entity(struct sched_dl_entity *dl_se,
}
}
+static inline u64 dl_next_period(struct sched_dl_entity *dl_se)
+{
+ return dl_se->deadline - dl_se->dl_deadline + dl_se->dl_period;
+}
+
/*
* If the entity depleted all its runtime, and if we want it to sleep
* while waiting for some new execution time to become available, we
- * set the bandwidth enforcement timer to the replenishment instant
+ * set the bandwidth replenishment timer to the replenishment instant
* and try to activate it.
*
* Notice that it is important for the caller to know if the timer
@@ -560,7 +565,7 @@ static int start_dl_timer(struct task_struct *p)
* that it is actually coming from rq->clock and not from
* hrtimer's time base reading.
*/
- act = ns_to_ktime(dl_se->deadline);
+ act = ns_to_ktime(dl_next_period(dl_se));
now = hrtimer_cb_get_time(timer);
delta = ktime_to_ns(now) - rq_clock(rq);
act = ktime_add_ns(act, delta);
@@ -724,6 +729,37 @@ void init_dl_task_timer(struct sched_dl_entity *dl_se)
timer->function = dl_task_timer;
}
+/*
+ * During the activation, CBS checks if it can reuse the current task's
+ * runtime and period. If the deadline of the task is in the past, CBS
+ * cannot use the runtime, and so it replenishes the task. This rule
+ * works fine for implicit deadline tasks (deadline == period), and the
+ * CBS was designed for implicit deadline tasks. However, a task with
+ * constrained deadline (deadine < period) might be awakened after the
+ * deadline, but before the next period. In this case, replenishing the
+ * task would allow it to run for runtime / deadline. As in this case
+ * deadline < period, CBS enables a task to run for more than the
+ * runtime / period. In a very loaded system, this can cause a domino
+ * effect, making other tasks miss their deadlines.
+ *
+ * To avoid this problem, in the activation of a constrained deadline
+ * task after the deadline but before the next period, throttle the
+ * task and set the replenishing timer to the begin of the next period,
+ * unless it is boosted.
+ */
+static inline void dl_check_constrained_dl(struct sched_dl_entity *dl_se)
+{
+ struct task_struct *p = dl_task_of(dl_se);
+ struct rq *rq = rq_of_dl_rq(dl_rq_of_se(dl_se));
+
+ if (dl_time_before(dl_se->deadline, rq_clock(rq)) &&
+ dl_time_before(rq_clock(rq), dl_next_period(dl_se))) {
+ if (unlikely(dl_se->dl_boosted || !start_dl_timer(p)))
+ return;
+ dl_se->dl_throttled = 1;
+ }
+}
+
static
int dl_runtime_exceeded(struct sched_dl_entity *dl_se)
{
@@ -1016,6 +1052,11 @@ static void dequeue_dl_entity(struct sched_dl_entity *dl_se)
__dequeue_dl_entity(dl_se);
}
+static inline bool dl_is_constrained(struct sched_dl_entity *dl_se)
+{
+ return dl_se->dl_deadline < dl_se->dl_period;
+}
+
static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags)
{
struct task_struct *pi_task = rt_mutex_get_top_task(p);
@@ -1042,6 +1083,15 @@ static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags)
}
/*
+ * Check if a constrained deadline task was activated
+ * after the deadline but before the next period.
+ * If that is the case, the task will be throttled and
+ * the replenishment timer will be set to the next period.
+ */
+ if (!p->dl.dl_throttled && dl_is_constrained(&p->dl))
+ dl_check_constrained_dl(&p->dl);
+
+ /*
* If p is throttled, we do nothing. In fact, if it exhausted
* its budget it needs a replenishment and, since it now is on
* its rq, the bandwidth timer callback (which clearly has not