Messages in this thread Patch in this message | | | Date | Fri, 28 Jan 2011 13:40:19 +0900 | From | Daisuke Nishimura <> | Subject | Re: [BUGFIX][PATCH 1/4] memcg: fix limit estimation at reclaim for hugepage |
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On Fri, 28 Jan 2011 12:24:49 +0900 KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote:
> From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> > > Current memory cgroup's code tends to assume page_size == PAGE_SIZE > and arrangement for THP is not enough yet. > > This is one of fixes for supporing THP. This adds > mem_cgroup_check_margin() and checks whether there are required amount of > free resource after memory reclaim. By this, THP page allocation > can know whether it really succeeded or not and avoid infinite-loop > and hangup. > > Total fixes for do_charge()/reclaim memory will follow this patch. > > Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
This patch looks good to me, but some nitpicks.
> --- > include/linux/res_counter.h | 11 +++++++++++ > mm/memcontrol.c | 25 ++++++++++++++++++++++++- > 2 files changed, 35 insertions(+), 1 deletion(-) > > Index: mmotm-0125/include/linux/res_counter.h > =================================================================== > --- mmotm-0125.orig/include/linux/res_counter.h > +++ mmotm-0125/include/linux/res_counter.h > @@ -182,6 +182,17 @@ static inline bool res_counter_check_und > return ret; > } > > +static inline s64 res_counter_check_margin(struct res_counter *cnt) > +{ > + s64 ret; > + unsigned long flags; > + > + spin_lock_irqsave(&cnt->lock, flags); > + ret = cnt->limit - cnt->usage; > + spin_unlock_irqrestore(&cnt->lock, flags); > + return ret; > +} > + > static inline bool res_counter_check_under_soft_limit(struct res_counter *cnt) > { > bool ret; > Index: mmotm-0125/mm/memcontrol.c > =================================================================== > --- mmotm-0125.orig/mm/memcontrol.c > +++ mmotm-0125/mm/memcontrol.c > @@ -1111,6 +1111,22 @@ static bool mem_cgroup_check_under_limit > return false; > } > > +static s64 mem_cgroup_check_margin(struct mem_cgroup *mem) > +{ > + s64 mem_margin; > + > + if (do_swap_account) { > + s64 memsw_margin; > + > + mem_margin = res_counter_check_margin(&mem->res); > + memsw_margin = res_counter_check_margin(&mem->memsw); > + if (mem_margin > memsw_margin) > + mem_margin = memsw_margin; > + } else > + mem_margin = res_counter_check_margin(&mem->res); > + return mem_margin; > +} > + How about
mem_margin = res_counter_check_margin(&mem->res); if (do_swap_account) memsw_margin = res_counter_check_margin(&mem->memsw); else memsw_margin = RESOURCE_MAX;
return min(mem_margin, memsw_margin);
? I think using min() makes it more clear what this function does.
> static unsigned int get_swappiness(struct mem_cgroup *memcg) > { > struct cgroup *cgrp = memcg->css.cgroup; > @@ -1853,7 +1869,14 @@ static int __mem_cgroup_do_charge(struct > * Check the limit again to see if the reclaim reduced the > * current usage of the cgroup before giving up > */ > - if (ret || mem_cgroup_check_under_limit(mem_over_limit)) > + if (mem_cgroup_check_margin(mem_over_limit) >= csize) > + return CHARGE_RETRY; > + > + /* > + * If the charge size is a PAGE_SIZE, it's not hopeless while > + * we can reclaim a page. > + */ > + if (csize == PAGE_SIZE && ret) > return CHARGE_RETRY; > > /* > checkpatch complains some whitespace warnings.
Thanks, Daisuke Nishimura.
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