Messages in this thread | | | Date | Thu, 9 Oct 2008 15:21:32 +0900 | From | Daisuke Nishimura <> | Subject | Re: [PATCH 6/6] memcg: lazy lru addition |
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On Wed, 1 Oct 2008 17:01:19 +0900, KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote: > Delaying add_to_lru() and do it in batched manner like page_vec. > For doing that 2 flags PCG_USED and PCG_LRU. > > Because __set_page_cgroup_lru() itself doesn't take lock_page_cgroup(), > we need a sanity check inside lru_lock(). > > And this delaying make css_put()/get() complicated. > To make it clear, > * css_get() is called from mem_cgroup_add_list(). > * css_put() is called from mem_cgroup_remove_list(). > * css_get()->css_put() is called while try_charge()->commit/cancel sequence. > is newly added. >
I like this new policy, but
> @@ -710,17 +774,18 @@ static void __mem_cgroup_commit_charge(s
=== if (PageCgroupLRU(pc)) { ClearPageCgroupLRU(pc); __mem_cgroup_remove_list(mz, pc); css_put(&pc->mem_cgroup->css); } spin_unlock_irqrestore(&mz->lru_lock, flags); } ===
Is this css_put needed yet?
> /* Here, PCG_LRU bit is cleared */ > pc->mem_cgroup = mem; > /* > + * We have to set pc->mem_cgroup before set USED bit for avoiding > + * race with (delayed) __set_page_cgroup_lru() in other cpu. > + */ > + smp_wmb(); > + /* > * below pcg_default_flags includes PCG_LOCK bit. > */ > pc->flags = pcg_default_flags[ctype]; > unlock_page_cgroup(pc); > > - mz = page_cgroup_zoneinfo(pc); > - > - spin_lock_irqsave(&mz->lru_lock, flags); > - __mem_cgroup_add_list(mz, pc, true); > - SetPageCgroupLRU(pc); > - spin_unlock_irqrestore(&mz->lru_lock, flags); > + set_page_cgroup_lru(pc); > + css_put(&mem->css); > } > > /**
Thanks, Daisuke Nishimura.
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