archives/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-03-08 03:44:45 +01:00
Code Issues Projects Releases Packages Wiki Activity Actions

memcg: Prepare to protect against concurrent isolated cpuset change

Browse source 
The HK_TYPE_DOMAIN housekeeping cpumask will soon be made modifiable at
runtime. In order to synchronize against memcg workqueue to make sure
that no asynchronous draining is pending or executing on a newly made
isolated CPU, target and queue a drain work under the same RCU critical
section.

Whenever housekeeping will update the HK_TYPE_DOMAIN cpumask, a memcg
workqueue flush will also be issued in a further change to make sure
that no work remains pending after a CPU has been made isolated.

Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Marco Crivellari <marco.crivellari@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Waiman Long <longman@redhat.com>
This commit is contained in:
Frederic Weisbecker 2025-05-15 17:10:51 +02:00
parent de715325cc
commit 2d05068610
1 changed files with 17 additions and 4 deletions
Download patch file Download diff file Expand all files Collapse all files

21
mm/memcontrol.c
View file

@ -2003,6 +2003,19 @@ static bool is_memcg_drain_needed(struct memcg_stock_pcp *stock,
return flush;
}
static void schedule_drain_work(int cpu, struct work_struct *work)
{
/*
* Protect housekeeping cpumask read and work enqueue together
* in the same RCU critical section so that later cpuset isolated
* partition update only need to wait for an RCU GP and flush the
* pending work on newly isolated CPUs.
*/
guard(rcu)();
if (!cpu_is_isolated(cpu))
schedule_work_on(cpu, work);
}
/*
* Drains all per-CPU charge caches for given root_memcg resp. subtree
* of the hierarchy under it.
@ -2032,8 +2045,8 @@ void drain_all_stock(struct mem_cgroup *root_memcg)
&memcg_st->flags)) {
if (cpu == curcpu)
drain_local_memcg_stock(&memcg_st->work);
else if (!cpu_is_isolated(cpu))
schedule_work_on(cpu, &memcg_st->work);
else
schedule_drain_work(cpu, &memcg_st->work);
}
if (!test_bit(FLUSHING_CACHED_CHARGE, &obj_st->flags) &&
@ -2042,8 +2055,8 @@ void drain_all_stock(struct mem_cgroup *root_memcg)
&obj_st->flags)) {
if (cpu == curcpu)
drain_local_obj_stock(&obj_st->work);
else if (!cpu_is_isolated(cpu))
schedule_work_on(cpu, &obj_st->work);
else
schedule_drain_work(cpu, &obj_st->work);
}
}
migrate_enable();