Re: [PATCH 8/8] mm: memcontrol: hook up vmpressure to socket pressure
From: Vladimir Davydov <hidden>
Date: 2015-10-22 18:58:10
Also in:
cgroups, linux-mm, lkml
On Thu, Oct 22, 2015 at 12:21:36AM -0400, Johannes Weiner wrote: ...
quoted hunk ↗ jump to hunk
@@ -185,8 +183,29 @@ static void vmpressure_work_fn(struct work_struct *work) vmpr->reclaimed = 0; spin_unlock(&vmpr->sr_lock); + level = vmpressure_calc_level(scanned, reclaimed); + + if (level > VMPRESSURE_LOW) {
So we start socket_pressure at MEDIUM. Why not at LOW or CRITICAL?
+ struct mem_cgroup *memcg; + /* + * Let the socket buffer allocator know that we are + * having trouble reclaiming LRU pages. + * + * For hysteresis, keep the pressure state asserted + * for a second in which subsequent pressure events + * can occur. + * + * XXX: is vmpressure a global feature or part of + * memcg? There shouldn't be anything memcg-specific + * about exporting reclaim success ratios from the VM. + */ + memcg = container_of(vmpr, struct mem_cgroup, vmpressure); + if (memcg != root_mem_cgroup) + memcg->socket_pressure = jiffies + HZ;
Why 1 second? Thanks, Vladimir
+ }
+
do {
- if (vmpressure_event(vmpr, scanned, reclaimed))
+ if (vmpressure_event(vmpr, level))
break;
/*
* If not handled, propagate the event upward into the