diff options
Diffstat (limited to '')
| -rw-r--r-- | debian/patches-rt/0292-sched-Optimize-migration_cpu_stop.patch | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/debian/patches-rt/0292-sched-Optimize-migration_cpu_stop.patch b/debian/patches-rt/0292-sched-Optimize-migration_cpu_stop.patch new file mode 100644 index 000000000..87ca79ca8 --- /dev/null +++ b/debian/patches-rt/0292-sched-Optimize-migration_cpu_stop.patch @@ -0,0 +1,58 @@ +From b1353ab8df1e6dd3bf9afaef3096749db2a193f1 Mon Sep 17 00:00:00 2001 +From: Peter Zijlstra <peterz@infradead.org> +Date: Tue, 8 Jun 2021 00:37:33 -0400 +Subject: [PATCH 292/323] sched: Optimize migration_cpu_stop() +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.10/older/patches-5.10.204-rt100.tar.xz + +commit 3f1bc119cd7fc987c8ed25ffb717f99403bb308c upstream. + +When the purpose of migration_cpu_stop() is to migrate the task to +'any' valid CPU, don't migrate the task when it's already running on a +valid CPU. + +Fixes: 6d337eab041d ("sched: Fix migrate_disable() vs set_cpus_allowed_ptr()") +Cc: stable@kernel.org +Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> +Signed-off-by: Ingo Molnar <mingo@kernel.org> +Reviewed-by: Valentin Schneider <valentin.schneider@arm.com> +Link: https://lkml.kernel.org/r/20210224131355.569238629@infradead.org +Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> +Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> +--- + kernel/sched/core.c | 13 ++++++++++++- + 1 file changed, 12 insertions(+), 1 deletion(-) + +diff --git a/kernel/sched/core.c b/kernel/sched/core.c +index 3130289baf79..e28fb33afa95 100644 +--- a/kernel/sched/core.c ++++ b/kernel/sched/core.c +@@ -1988,14 +1988,25 @@ static int migration_cpu_stop(void *data) + complete = true; + } + +- if (dest_cpu < 0) ++ if (dest_cpu < 0) { ++ if (cpumask_test_cpu(task_cpu(p), &p->cpus_mask)) ++ goto out; ++ + dest_cpu = cpumask_any_distribute(&p->cpus_mask); ++ } + + if (task_on_rq_queued(p)) + rq = __migrate_task(rq, &rf, p, dest_cpu); + else + p->wake_cpu = dest_cpu; + ++ /* ++ * XXX __migrate_task() can fail, at which point we might end ++ * up running on a dodgy CPU, AFAICT this can only happen ++ * during CPU hotplug, at which point we'll get pushed out ++ * anyway, so it's probably not a big deal. ++ */ ++ + } else if (pending) { + /* + * This happens when we get migrated between migrate_enable()'s +-- +2.43.0 + |