user/sven/linux.git/include/linux/preempt.h, branch v4.10.16

x86/uaccess, sched/preempt: Verify access_ok() context

2016-12-06T09:32:40Z

I recently encountered wreckage because access_ok() was used where it should not be, add an explicit WARN when access_ok() is used wrongly. Signed-off-by: Peter Zijlstra (Intel) Cc: Andy Lutomirski Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

sched/core: Kill PREEMPT_ACTIVE

2015-10-06T15:08:19Z

Its unused, kill the definition. Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Thomas Gleixner Reviewed-by: Steven Rostedt Reviewed-by: Frederic Weisbecker Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

sched/core: Simplify preempt_count tests

2015-10-06T15:08:17Z

Since we stopped setting PREEMPT_ACTIVE, there is no need to mask it out of preempt_count() tests. Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Thomas Gleixner Reviewed-by: Steven Rostedt Reviewed-by: Frederic Weisbecker Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

sched/core: Stop setting PREEMPT_ACTIVE

2015-10-06T15:08:16Z

Now that nothing tests for PREEMPT_ACTIVE anymore, stop setting it. Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Thomas Gleixner Reviewed-by: Steven Rostedt Reviewed-by: Frederic Weisbecker Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

sched/preempt: Fix cond_resched_lock() and cond_resched_softirq()

2015-08-03T10:21:24Z

These functions check should_resched() before unlocking spinlock/bh-enable: preempt_count always non-zero => should_resched() always returns false. cond_resched_lock() worked iff spin_needbreak is set. This patch adds argument "preempt_offset" to should_resched(). preempt_count offset constants for that: PREEMPT_DISABLE_OFFSET - offset after preempt_disable() PREEMPT_LOCK_OFFSET - offset after spin_lock() SOFTIRQ_DISABLE_OFFSET - offset after local_bh_distable() SOFTIRQ_LOCK_OFFSET - offset after spin_lock_bh() Signed-off-by: Konstantin Khlebnikov Signed-off-by: Peter Zijlstra (Intel) Cc: Alexander Graf Cc: Boris Ostrovsky Cc: David Vrabel Cc: Linus Torvalds Cc: Mike Galbraith Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Thomas Gleixner Fixes: bdb438065890 ("sched: Extract the basic add/sub preempt_count modifiers") Link: http://lkml.kernel.org/r/20150715095204.12246.98268.stgit@buzz Signed-off-by: Ingo Molnar

sched, preempt_notifier: separate notifier registration from static_key inc/dec

2015-07-03T16:55:00Z

Commit 1cde2930e154 ("sched/preempt: Add static_key() to preempt_notifiers") had two problems. First, the preempt-notifier API needs to sleep with the addition of the static_key, we do however need to hold off preemption while modifying the preempt notifier list, otherwise a preemption could observe an inconsistent list state. KVM correctly registers and unregisters preempt notifiers with preemption disabled, so the sleep caused dmesg splats. Second, KVM registers and unregisters preemption notifiers very often (in vcpu_load/vcpu_put). With a single uniprocessor guest the static key would move between 0 and 1 continuously, hitting the slow path on every userspace exit. To fix this, wrap the static_key inc/dec in a new API, and call it from KVM. Fixes: 1cde2930e154 ("sched/preempt: Add static_key() to preempt_notifiers") Reported-by: Pontus Fuchs Reported-by: Takashi Iwai Tested-by: Takashi Iwai Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Paolo Bonzini

preempt: Reorganize the notrace definitions a bit

2015-06-07T13:57:43Z

preempt.h has two seperate "#ifdef CONFIG_PREEMPT" sections: one to define preempt_enable() and another to define preempt_enable_notrace(). Lets gather both. Signed-off-by: Frederic Weisbecker Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Fengguang Wu Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1433432349-1021-4-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar

preempt: Use preempt_schedule_context() as the official tracing preemption point

2015-06-07T13:57:42Z

preempt_schedule_context() is a tracing safe preemption point but it's only used when CONFIG_CONTEXT_TRACKING=y. Other configs have tracing recursion issues since commit: b30f0e3ffedf ("sched/preempt: Optimize preemption operations on __schedule() callers") introduced function based preemp_count_*() ops. Lets make it available on all configs and give it a more appropriate name for its new position. Reported-by: Fengguang Wu Signed-off-by: Frederic Weisbecker Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1433432349-1021-3-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar

sched/preempt: Remove PREEMPT_ACTIVE unmasking off in_atomic()

2015-05-19T06:39:13Z

Now that PREEMPT_ACTIVE implies PREEMPT_DISABLE_OFFSET, ignoring PREEMPT_ACTIVE from in_atomic() check isn't useful anymore. Signed-off-by: Frederic Weisbecker Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1431441711-29753-7-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar

sched/preempt: Fix out of date comment

2015-05-19T06:39:13Z

Signed-off-by: Frederic Weisbecker Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1431441711-29753-6-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar