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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-12-21 10:52:10 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-12-21 10:52:10 -0800 |
| commit | fd7a6d2b8f1d67df76d0e863f003162b931074a1 (patch) | |
| tree | 060c71ca1d2b76d0036787eb4444432bd2bdc536 /kernel/sched | |
| parent | c4ff10efe8e487cd35f4475ed2dd1e5e0c6f784a (diff) | |
| parent | 6cf82d559e1a1d89f06ff4d428aca479c1dd0be6 (diff) | |
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 fixes: a (rare) PSI crash fix, a CPU affinity related balancing
fix, and a toning down of active migration attempts"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/cfs: fix spurious active migration
sched/fair: Fix find_idlest_group() to handle CPU affinity
psi: Fix a division error in psi poll()
sched/psi: Fix sampling error and rare div0 crashes with cgroups and high uptime
Diffstat (limited to 'kernel/sched')
| -rw-r--r-- | kernel/sched/fair.c | 13 | ||||
| -rw-r--r-- | kernel/sched/psi.c | 5 |
2 files changed, 15 insertions, 3 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 08a233e97a01..ba749f579714 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7328,7 +7328,14 @@ static int detach_tasks(struct lb_env *env) load < 16 && !env->sd->nr_balance_failed) goto next; - if (load/2 > env->imbalance) + /* + * Make sure that we don't migrate too much load. + * Nevertheless, let relax the constraint if + * scheduler fails to find a good waiting task to + * migrate. + */ + if (load/2 > env->imbalance && + env->sd->nr_balance_failed <= env->sd->cache_nice_tries) goto next; env->imbalance -= load; @@ -8417,6 +8424,10 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p, if (!idlest) return NULL; + /* The local group has been skipped because of CPU affinity */ + if (!local) + return idlest; + /* * If the local group is idler than the selected idlest group * don't try and push the task. diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c index 517e3719027e..ce8f6748678a 100644 --- a/kernel/sched/psi.c +++ b/kernel/sched/psi.c @@ -185,7 +185,8 @@ static void group_init(struct psi_group *group) for_each_possible_cpu(cpu) seqcount_init(&per_cpu_ptr(group->pcpu, cpu)->seq); - group->avg_next_update = sched_clock() + psi_period; + group->avg_last_update = sched_clock(); + group->avg_next_update = group->avg_last_update + psi_period; INIT_DELAYED_WORK(&group->avgs_work, psi_avgs_work); mutex_init(&group->avgs_lock); /* Init trigger-related members */ @@ -481,7 +482,7 @@ static u64 window_update(struct psi_window *win, u64 now, u64 value) u32 remaining; remaining = win->size - elapsed; - growth += div_u64(win->prev_growth * remaining, win->size); + growth += div64_u64(win->prev_growth * remaining, win->size); } return growth; |