Merge android-4.4.114 (fe09418) into msm-4.4

* refs/heads/tmp-fe09418
  Linux 4.4.114
  nfsd: auth: Fix gid sorting when rootsquash enabled
  net: tcp: close sock if net namespace is exiting
  flow_dissector: properly cap thoff field
  ipv4: Make neigh lookup keys for loopback/point-to-point devices be INADDR_ANY
  net: Allow neigh contructor functions ability to modify the primary_key
  vmxnet3: repair memory leak
  sctp: return error if the asoc has been peeled off in sctp_wait_for_sndbuf
  sctp: do not allow the v4 socket to bind a v4mapped v6 address
  r8169: fix memory corruption on retrieval of hardware statistics.
  pppoe: take ->needed_headroom of lower device into account on xmit
  net: qdisc_pkt_len_init() should be more robust
  tcp: __tcp_hdrlen() helper
  net: igmp: fix source address check for IGMPv3 reports
  lan78xx: Fix failure in USB Full Speed
  ipv6: ip6_make_skb() needs to clear cork.base.dst
  ipv6: fix udpv6 sendmsg crash caused by too small MTU
  ipv6: Fix getsockopt() for sockets with default IPV6_AUTOFLOWLABEL
  dccp: don't restart ccid2_hc_tx_rto_expire() if sk in closed state
  hrtimer: Reset hrtimer cpu base proper on CPU hotplug
  x86/microcode/intel: Extend BDW late-loading further with LLC size check
  eventpoll.h: add missing epoll event masks
  vsyscall: Fix permissions for emulate mode with KAISER/PTI
  um: link vmlinux with -no-pie
  usbip: prevent leaking socket pointer address in messages
  usbip: fix stub_rx: harden CMD_SUBMIT path to handle malicious input
  usbip: fix stub_rx: get_pipe() to validate endpoint number
  usb: usbip: Fix possible deadlocks reported by lockdep
  Input: trackpoint - force 3 buttons if 0 button is reported
  Revert "module: Add retpoline tag to VERMAGIC"
  scsi: libiscsi: fix shifting of DID_REQUEUE host byte
  fs/fcntl: f_setown, avoid undefined behaviour
  reiserfs: Don't clear SGID when inheriting ACLs
  reiserfs: don't preallocate blocks for extended attributes
  reiserfs: fix race in prealloc discard
  ext2: Don't clear SGID when inheriting ACLs
  netfilter: xt_osf: Add missing permission checks
  netfilter: nfnetlink_cthelper: Add missing permission checks
  netfilter: fix IS_ERR_VALUE usage
  netfilter: use fwmark_reflect in nf_send_reset
  netfilter: nf_conntrack_sip: extend request line validation
  netfilter: restart search if moved to other chain
  netfilter: nfnetlink_queue: reject verdict request from different portid
  netfilter: nf_ct_expect: remove the redundant slash when policy name is empty
  netfilter: nf_dup_ipv6: set again FLOWI_FLAG_KNOWN_NH at flowi6_flags
  netfilter: arp_tables: fix invoking 32bit "iptable -P INPUT ACCEPT" failed in 64bit kernel
  netfilter: x_tables: speed up jump target validation
  ACPICA: Namespace: fix operand cache leak
  ACPI / scan: Prefer devices without _HID/_CID for _ADR matching
  ACPI / processor: Avoid reserving IO regions too early
  x86/ioapic: Fix incorrect pointers in ioapic_setup_resources()
  ipc: msg, make msgrcv work with LONG_MIN
  mm, page_alloc: fix potential false positive in __zone_watermark_ok
  cma: fix calculation of aligned offset
  hwpoison, memcg: forcibly uncharge LRU pages
  mm/mmap.c: do not blow on PROT_NONE MAP_FIXED holes in the stack
  fs/select: add vmalloc fallback for select(2)
  mmc: sdhci-of-esdhc: add/remove some quirks according to vendor version
  PCI: layerscape: Fix MSG TLP drop setting
  PCI: layerscape: Add "fsl,ls2085a-pcie" compatible ID
  drivers: base: cacheinfo: fix boot error message when acpi is enabled
  drivers: base: cacheinfo: fix x86 with CONFIG_OF enabled
  Prevent timer value 0 for MWAITX
  timers: Plug locking race vs. timer migration
  time: Avoid undefined behaviour in ktime_add_safe()
  PM / sleep: declare __tracedata symbols as char[] rather than char
  can: af_can: canfd_rcv(): replace WARN_ONCE by pr_warn_once
  can: af_can: can_rcv(): replace WARN_ONCE by pr_warn_once
  sched/deadline: Use the revised wakeup rule for suspending constrained dl tasks
  x86/retpoline: Fill RSB on context switch for affected CPUs
  x86/cpu/intel: Introduce macros for Intel family numbers
  x86/microcode/intel: Fix BDW late-loading revision check
  usbip: Fix potential format overflow in userspace tools
  usbip: Fix implicit fallthrough warning
  usbip: prevent vhci_hcd driver from leaking a socket pointer address
  x86/asm/32: Make sync_core() handle missing CPUID on all 32-bit kernels
  ANDROID: sched: EAS: check energy_aware() before calling select_energy_cpu_brute() in up-migrate path
  UPSTREAM: eventpoll.h: add missing epoll event masks
  ANDROID: xattr: Pass EOPNOTSUPP to permission2

Conflicts:
	kernel/sched/fair.c

Change-Id: I15005cb3bc039f4361d25ed2e22f8175b3d7ca96
Signed-off-by: Srinivasarao P <spathi@codeaurora.org>

2 files changed, 88 insertions, 12 deletions

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 8db48e263f8e..59ba1d1266a7 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2289,6 +2289,7 @@ void __dl_clear_params(struct task_struct *p)
 	dl_se->dl_period = 0;
 	dl_se->flags = 0;
 	dl_se->dl_bw = 0;
+	dl_se->dl_density = 0;
 
 	dl_se->dl_throttled = 0;
 	dl_se->dl_new = 1;
@@ -3991,6 +3992,7 @@ __setparam_dl(struct task_struct *p, const struct sched_attr *attr)
 	dl_se->dl_period = attr->sched_period ?: dl_se->dl_deadline;
 	dl_se->flags = attr->sched_flags;
 	dl_se->dl_bw = to_ratio(dl_se->dl_period, dl_se->dl_runtime);
+	dl_se->dl_density = to_ratio(dl_se->dl_deadline, dl_se->dl_runtime);
 
 	/*
 	 * Changing the parameters of a task is 'tricky' and we're not doing
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 105f6cdac6fc..188c8388a63f 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -502,13 +502,84 @@ static bool dl_entity_overflow(struct sched_dl_entity *dl_se,
 }
 
 /*
- * When a -deadline entity is queued back on the runqueue, its runtime and
- * deadline might need updating.
+ * Revised wakeup rule [1]: For self-suspending tasks, rather then
+ * re-initializing task's runtime and deadline, the revised wakeup
+ * rule adjusts the task's runtime to avoid the task to overrun its
+ * density.
  *
- * The policy here is that we update the deadline of the entity only if:
- *  - the current deadline is in the past,
- *  - using the remaining runtime with the current deadline would make
- *    the entity exceed its bandwidth.
+ * Reasoning: a task may overrun the density if:
+ *    runtime / (deadline - t) > dl_runtime / dl_deadline
+ *
+ * Therefore, runtime can be adjusted to:
+ *     runtime = (dl_runtime / dl_deadline) * (deadline - t)
+ *
+ * In such way that runtime will be equal to the maximum density
+ * the task can use without breaking any rule.
+ *
+ * [1] Luca Abeni, Giuseppe Lipari, and Juri Lelli. 2015. Constant
+ * bandwidth server revisited. SIGBED Rev. 11, 4 (January 2015), 19-24.
+ */
+static void
+update_dl_revised_wakeup(struct sched_dl_entity *dl_se, struct rq *rq)
+{
+	u64 laxity = dl_se->deadline - rq_clock(rq);
+
+	/*
+	 * If the task has deadline < period, and the deadline is in the past,
+	 * it should already be throttled before this check.
+	 *
+	 * See update_dl_entity() comments for further details.
+	 */
+	WARN_ON(dl_time_before(dl_se->deadline, rq_clock(rq)));
+
+	dl_se->runtime = (dl_se->dl_density * laxity) >> 20;
+}
+
+/*
+ * Regarding the deadline, a task with implicit deadline has a relative
+ * deadline == relative period. A task with constrained deadline has a
+ * relative deadline <= relative period.
+ *
+ * We support constrained deadline tasks. However, there are some restrictions
+ * applied only for tasks which do not have an implicit deadline. See
+ * update_dl_entity() to know more about such restrictions.
+ *
+ * The dl_is_implicit() returns true if the task has an implicit deadline.
+ */
+static inline bool dl_is_implicit(struct sched_dl_entity *dl_se)
+{
+	return dl_se->dl_deadline == dl_se->dl_period;
+}
+
+/*
+ * When a deadline entity is placed in the runqueue, its runtime and deadline
+ * might need to be updated. This is done by a CBS wake up rule. There are two
+ * different rules: 1) the original CBS; and 2) the Revisited CBS.
+ *
+ * When the task is starting a new period, the Original CBS is used. In this
+ * case, the runtime is replenished and a new absolute deadline is set.
+ *
+ * When a task is queued before the begin of the next period, using the
+ * remaining runtime and deadline could make the entity to overflow, see
+ * dl_entity_overflow() to find more about runtime overflow. When such case
+ * is detected, the runtime and deadline need to be updated.
+ *
+ * If the task has an implicit deadline, i.e., deadline == period, the Original
+ * CBS is applied. the runtime is replenished and a new absolute deadline is
+ * set, as in the previous cases.
+ *
+ * However, the Original CBS does not work properly for tasks with
+ * deadline < period, which are said to have a constrained deadline. By
+ * applying the Original CBS, a constrained deadline task would be able to run
+ * runtime/deadline in a period. With deadline < period, the task would
+ * overrun the runtime/period allowed bandwidth, breaking the admission test.
+ *
+ * In order to prevent this misbehave, the Revisited CBS is used for
+ * constrained deadline tasks when a runtime overflow is detected. In the
+ * Revisited CBS, rather than replenishing & setting a new absolute deadline,
+ * the remaining runtime of the task is reduced to avoid runtime overflow.
+ * Please refer to the comments update_dl_revised_wakeup() function to find
+ * more about the Revised CBS rule.
  */
 static void update_dl_entity(struct sched_dl_entity *dl_se,
 			     struct sched_dl_entity *pi_se)
@@ -530,6 +601,14 @@ static void update_dl_entity(struct sched_dl_entity *dl_se,
 
 	if (dl_time_before(dl_se->deadline, rq_clock(rq)) ||
 	    dl_entity_overflow(dl_se, pi_se, rq_clock(rq))) {
+
+		if (unlikely(!dl_is_implicit(dl_se) &&
+			     !dl_time_before(dl_se->deadline, rq_clock(rq)) &&
+			     !dl_se->dl_boosted)){
+			update_dl_revised_wakeup(dl_se, rq);
+			return;
+		}
+
 		dl_se->deadline = rq_clock(rq) + pi_se->dl_deadline;
 		dl_se->runtime = pi_se->dl_runtime;
 	}
@@ -1054,11 +1133,6 @@ 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);
@@ -1090,7 +1164,7 @@ static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags)
 	 * 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))
+	if (!p->dl.dl_throttled && !dl_is_implicit(&p->dl))
 		dl_check_constrained_dl(&p->dl);
 
 	/*