From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konstantin Khlebnikov Subject: Re: [PATCH] memcg: rework inactive_ratio logic Date: Thu, 16 Feb 2012 10:57:14 +0400 Message-ID: <4F3CA8CA.8020004@openvz.org> References: <20120215162442.13588.21790.stgit@zurg> <20120216103842.0c3e9258.kamezawa.hiroyu@jp.fujitsu.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=sender:message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; bh=bZlg1J6P5vwdNkp0slFV6Go+gXVxY3VmCdw41YN6xb4=; b=cMVDpaghctIYZ7xNhty5nhUMd7Oo1J4o5D00zCtSJkfw8xBVHF728LDw0X0UzDaNUj Chut7C0bCS2Bpj1DZ+Mu52qwXqg29U0UWNjvYM+iI625xbSvSJzHZuoozdHCtJwGG/I8 0aDEj8zcPuAKVV07oYJZdus1MMo5SDmF9qUgQ= In-Reply-To: <20120216103842.0c3e9258.kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: KAMEZAWA Hiroyuki Cc: "linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org" , Andrew Morton , Johannes Weiner , "cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" KAMEZAWA Hiroyuki wrote: > On Wed, 15 Feb 2012 20:24:42 +0400 > Konstantin Khlebnikov wrote: > >> This patch adds mem_cgroup->inactive_ratio calculated from hierarchical memory limit. >> It updated at each limit change before shrinking cgroup to this new limit. >> Ratios for all child cgroups are updated too, because parent limit can affect them. >> Update precedure can be greatly optimized if its performance becomes the problem. >> Inactive ratio for unlimited or huge limit does not matter, because we'll never hit it. >> >> At global reclaim always use global ratio from zone->inactive_ratio. >> At mem-cgroup reclaim use inactive_ratio from target memory cgroup, >> this is cgroup which hit its limit and cause this reclaimer invocation. >> >> Thus, global memory reclaimer will try to keep ratio for all lru lists in zone >> above one mark, this guarantee that total ratio in this zone will be above too. >> Meanwhile mem-cgroup will do the same thing for its lru lists in all zones, and >> for all lru lists in all sub-cgroups in hierarchy. >> >> Also this patch removes some redundant code. >> >> Signed-off-by: Konstantin Khlebnikov > > Hmm, the main purpose of this patch is to remove calculation per get_scan_ratio() ? Technically, it was preparation for "mm: unify inactive_list_is_low()" from "memory book keeping" patchset. So, actually its main purpose is moving all active/inactive size calculation to mm/vmscan.c Also I trying to figure out most sane logic for inactive_ratio calculation, currently global memory reclaimer sometimes uses memcg-calculated ratio, it looks strange. >> --- >> include/linux/memcontrol.h | 16 ++------ >> mm/memcontrol.c | 85 ++++++++++++++++++++++++-------------------- >> mm/vmscan.c | 82 +++++++++++++++++++++++------------------- >> 3 files changed, 93 insertions(+), 90 deletions(-) >> static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, >> unsigned long long val) >> { >> @@ -3422,6 +3416,7 @@ static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, >> else >> memcg->memsw_is_minimum = false; >> } >> + mem_cgroup_update_inactive_ratio(memcg, val); >> mutex_unlock(&set_limit_mutex); >> >> if (!ret) >> @@ -3439,6 +3434,12 @@ static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, >> if (!ret&& enlarge) >> memcg_oom_recover(memcg); >> >> + if (ret) { >> + mutex_lock(&set_limit_mutex); >> + mem_cgroup_update_inactive_ratio(memcg, RESOURCE_MAX); >> + mutex_unlock(&set_limit_mutex); >> + } > > Why RESOUECE_MAX ? resize was failed, so we return back normal value calculated from the current limit. target == RESOURCE_MAX isn't clip limit: min(RESOURCE_MAX, limit) == limit > > Thanks, > -Kame >