Re: [PATCH RT 4/5] allow preemption in mem_cgroup_move_account_page_stat
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: 2014-02-14 13:17:09
Also in:
lkml
* Nicholas Mc Guire | 2014-02-10 16:39:33 [+0100]:
quoted hunk ↗ jump to hunk
index a67e630f..e7cc35a 100644--- a/mm/memcontrol.c +++ b/mm/memcontrol.c@@ -3784,10 +3784,10 @@ void mem_cgroup_move_account_page_stat(struct mem_cgroup *from,enum mem_cgroup_stat_index idx) { /* Update stat data for mem_cgroup */ - preempt_disable(); + migrate_disable(); __this_cpu_sub(from->stat->count[idx], nr_pages); __this_cpu_add(to->stat->count[idx], nr_pages); - preempt_enable(); + migrate_enable(); }
Now, that I look at it again. Isn't it more efficient to keep preemption disabled for this very short time instead instead of invoking migrate_disable() which includes preempt_disable()/enable() and a few more opcodes… Therefore, I drop it again. Sebastian