diff options
Diffstat (limited to 'debian/patches-rt/0172-sched-Add-saved_state-for-tasks-blocked-on-sleeping-.patch')
| -rw-r--r-- | debian/patches-rt/0172-sched-Add-saved_state-for-tasks-blocked-on-sleeping-.patch | 116 |
1 files changed, 0 insertions, 116 deletions
diff --git a/debian/patches-rt/0172-sched-Add-saved_state-for-tasks-blocked-on-sleeping-.patch b/debian/patches-rt/0172-sched-Add-saved_state-for-tasks-blocked-on-sleeping-.patch deleted file mode 100644 index 6196609fd..000000000 --- a/debian/patches-rt/0172-sched-Add-saved_state-for-tasks-blocked-on-sleeping-.patch +++ /dev/null @@ -1,116 +0,0 @@ -From b5dad6705d942c5cecc690b89cb988847928f953 Mon Sep 17 00:00:00 2001 -From: Thomas Gleixner <tglx@linutronix.de> -Date: Sat, 25 Jun 2011 09:21:04 +0200 -Subject: [PATCH 172/296] sched: Add saved_state for tasks blocked on sleeping - locks -Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.10/older/patches-5.10.35-rt39.tar.xz - -Spinlocks are state preserving in !RT. RT changes the state when a -task gets blocked on a lock. So we need to remember the state before -the lock contention. If a regular wakeup (not a RTmutex related -wakeup) happens, the saved_state is updated to running. When the lock -sleep is done, the saved state is restored. - -Signed-off-by: Thomas Gleixner <tglx@linutronix.de> ---- - include/linux/sched.h | 3 +++ - kernel/sched/core.c | 34 ++++++++++++++++++++++++++++++++-- - kernel/sched/sched.h | 1 + - 3 files changed, 36 insertions(+), 2 deletions(-) - -diff --git a/include/linux/sched.h b/include/linux/sched.h -index 1a146988088d..796ea634da89 100644 ---- a/include/linux/sched.h -+++ b/include/linux/sched.h -@@ -655,6 +655,8 @@ struct task_struct { - #endif - /* -1 unrunnable, 0 runnable, >0 stopped: */ - volatile long state; -+ /* saved state for "spinlock sleepers" */ -+ volatile long saved_state; - - /* - * This begins the randomizable portion of task_struct. Only -@@ -1772,6 +1774,7 @@ extern struct task_struct *find_get_task_by_vpid(pid_t nr); - - extern int wake_up_state(struct task_struct *tsk, unsigned int state); - extern int wake_up_process(struct task_struct *tsk); -+extern int wake_up_lock_sleeper(struct task_struct *tsk); - extern void wake_up_new_task(struct task_struct *tsk); - - #ifdef CONFIG_SMP -diff --git a/kernel/sched/core.c b/kernel/sched/core.c -index 6763a6ec8715..200b37c704de 100644 ---- a/kernel/sched/core.c -+++ b/kernel/sched/core.c -@@ -3282,7 +3282,7 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) - int cpu, success = 0; - - preempt_disable(); -- if (p == current) { -+ if (!IS_ENABLED(CONFIG_PREEMPT_RT) && p == current) { - /* - * We're waking current, this means 'p->on_rq' and 'task_cpu(p) - * == smp_processor_id()'. Together this means we can special -@@ -3312,8 +3312,26 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) - */ - raw_spin_lock_irqsave(&p->pi_lock, flags); - smp_mb__after_spinlock(); -- if (!(p->state & state)) -+ if (!(p->state & state)) { -+ /* -+ * The task might be running due to a spinlock sleeper -+ * wakeup. Check the saved state and set it to running -+ * if the wakeup condition is true. -+ */ -+ if (!(wake_flags & WF_LOCK_SLEEPER)) { -+ if (p->saved_state & state) { -+ p->saved_state = TASK_RUNNING; -+ success = 1; -+ } -+ } - goto unlock; -+ } -+ /* -+ * If this is a regular wakeup, then we can unconditionally -+ * clear the saved state of a "lock sleeper". -+ */ -+ if (!(wake_flags & WF_LOCK_SLEEPER)) -+ p->saved_state = TASK_RUNNING; - - trace_sched_waking(p); - -@@ -3502,6 +3520,18 @@ int wake_up_process(struct task_struct *p) - } - EXPORT_SYMBOL(wake_up_process); - -+/** -+ * wake_up_lock_sleeper - Wake up a specific process blocked on a "sleeping lock" -+ * @p: The process to be woken up. -+ * -+ * Same as wake_up_process() above, but wake_flags=WF_LOCK_SLEEPER to indicate -+ * the nature of the wakeup. -+ */ -+int wake_up_lock_sleeper(struct task_struct *p) -+{ -+ return try_to_wake_up(p, TASK_UNINTERRUPTIBLE, WF_LOCK_SLEEPER); -+} -+ - int wake_up_state(struct task_struct *p, unsigned int state) - { - return try_to_wake_up(p, state, 0); -diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h -index 605f803937f0..32ac4fc0ce76 100644 ---- a/kernel/sched/sched.h -+++ b/kernel/sched/sched.h -@@ -1744,6 +1744,7 @@ static inline int task_on_rq_migrating(struct task_struct *p) - #define WF_FORK 0x02 /* Child wakeup after fork */ - #define WF_MIGRATED 0x04 /* Internal use, task got migrated */ - #define WF_ON_CPU 0x08 /* Wakee is on_cpu */ -+#define WF_LOCK_SLEEPER 0x10 /* Wakeup spinlock "sleeper" */ - - /* - * To aid in avoiding the subversion of "niceness" due to uneven distribution --- -2.30.2 - |