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Commit af788e35 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull scheduler fixes from Ingo Molnar:
 "Misc fixlets"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/cputime: Fix accounting on multi-threaded processes
  sched/debug: Fix sd->*_idx limit range avoiding overflow
  sched_clock: Prevent 64bit inatomicity on 32bit systems
  sched: Convert BUG_ON()s in try_to_wake_up_local() to WARN_ON_ONCE()s
parents ae9f4939 e614b333

kernel/sched/clock.c

+26 −0
Original line number Diff line number Diff line
@@ -176,10 +176,36 @@ static u64 sched_clock_remote(struct sched_clock_data *scd) 
	u64 this_clock, remote_clock;

	u64 *ptr, old_val, val;



#if BITS_PER_LONG != 64

again:

	/*

	 * Careful here: The local and the remote clock values need to

	 * be read out atomic as we need to compare the values and

	 * then update either the local or the remote side. So the

	 * cmpxchg64 below only protects one readout.

	 *

	 * We must reread via sched_clock_local() in the retry case on

	 * 32bit as an NMI could use sched_clock_local() via the

	 * tracer and hit between the readout of

	 * the low32bit and the high 32bit portion.

	 */

	this_clock = sched_clock_local(my_scd);

	/*

	 * We must enforce atomic readout on 32bit, otherwise the

	 * update on the remote cpu can hit inbetween the readout of

	 * the low32bit and the high 32bit portion.

	 */

	remote_clock = cmpxchg64(&scd->clock, 0, 0);

#else

	/*

	 * On 64bit the read of [my]scd->clock is atomic versus the

	 * update, so we can avoid the above 32bit dance.

	 */

	sched_clock_local(my_scd);

again:

	this_clock = my_scd->clock;

	remote_clock = scd->clock;

#endif



	/*

	 * Use the opportunity that we have both locks

kernel/sched/core.c

+5 −3
Original line number Diff line number Diff line
@@ -1498,8 +1498,10 @@ static void try_to_wake_up_local(struct task_struct *p) 
{

	struct rq *rq = task_rq(p);



	BUG_ON(rq != this_rq());

	BUG_ON(p == current);

	if (WARN_ON_ONCE(rq != this_rq()) ||

	    WARN_ON_ONCE(p == current))

		return;



	lockdep_assert_held(&rq->lock);



	if (!raw_spin_trylock(&p->pi_lock)) {
@@ -4999,7 +5001,7 @@ static void sd_free_ctl_entry(struct ctl_table **tablep) 
}



static int min_load_idx = 0;

static int max_load_idx = CPU_LOAD_IDX_MAX;

static int max_load_idx = CPU_LOAD_IDX_MAX-1;



static void

set_table_entry(struct ctl_table *entry,

kernel/sched/cputime.c

+1 −1
Original line number Diff line number Diff line
@@ -310,7 +310,7 @@ void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times) 


	t = tsk;

	do {

		task_cputime(tsk, &utime, &stime);

		task_cputime(t, &utime, &stime);

		times->utime += utime;

		times->stime += stime;

		times->sum_exec_runtime += task_sched_runtime(t);