From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754847Ab0KIXWr (ORCPT ); Tue, 9 Nov 2010 18:22:47 -0500 Received: from mail-iw0-f174.google.com ([209.85.214.174]:56739 "EHLO mail-iw0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753520Ab0KIXWp convert rfc822-to-8bit (ORCPT ); Tue, 9 Nov 2010 18:22:45 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=BhOQBLBwjunYZDFYpSMeQkCZWtzKt5SjNUQR1/K/23iZHLDn+FbUCI60gtCLgyL7JB gCFlAMyOOimiYIFWzek2Ge+/OZcwCxveuEF25pOTqeGcFWpsFE2wYUyvis4svHAIo5rd XhcRgBwxkA6qIodQCwpOnGCZgntNDqfqk6WD8= MIME-Version: 1.0 In-Reply-To: <1289294671-6865-4-git-send-email-gthelen@google.com> References: <1289294671-6865-1-git-send-email-gthelen@google.com> <1289294671-6865-4-git-send-email-gthelen@google.com> Date: Wed, 10 Nov 2010 08:22:44 +0900 Message-ID: Subject: Re: [PATCH 3/6] memcg: make throttle_vm_writeout() memcg aware From: Minchan Kim To: Greg Thelen Cc: Andrew Morton , Balbir Singh , KAMEZAWA Hiroyuki , Daisuke Nishimura , Johannes Weiner , Wu Fengguang , linux-mm@kvack.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 9, 2010 at 6:24 PM, Greg Thelen wrote: > If called with a mem_cgroup, then throttle_vm_writeout() should > query the given cgroup for its dirty memory usage limits. > > dirty_writeback_pages() is no longer used, so delete it. > > Signed-off-by: Greg Thelen Reviewed-by: Minchan Kim > --- >  include/linux/writeback.h |    2 +- >  mm/page-writeback.c       |   31 ++++++++++++++++--------------- >  mm/vmscan.c               |    2 +- >  3 files changed, 18 insertions(+), 17 deletions(-) > > diff --git a/include/linux/writeback.h b/include/linux/writeback.h > index 335dba1..1bacdda 100644 > --- a/include/linux/writeback.h > +++ b/include/linux/writeback.h > @@ -97,7 +97,7 @@ void laptop_mode_timer_fn(unsigned long data); >  #else >  static inline void laptop_sync_completion(void) { } >  #endif > -void throttle_vm_writeout(gfp_t gfp_mask); > +void throttle_vm_writeout(gfp_t gfp_mask, struct mem_cgroup *mem_cgroup); > >  /* These are exported to sysctl. */ >  extern int dirty_background_ratio; > diff --git a/mm/page-writeback.c b/mm/page-writeback.c > index d717fa9..bf85062 100644 > --- a/mm/page-writeback.c > +++ b/mm/page-writeback.c > @@ -131,18 +131,6 @@ EXPORT_SYMBOL(laptop_mode); >  static struct prop_descriptor vm_completions; >  static struct prop_descriptor vm_dirties; > > -static unsigned long dirty_writeback_pages(void) > -{ > -       unsigned long ret; > - > -       ret = mem_cgroup_page_stat(NULL, MEMCG_NR_DIRTY_WRITEBACK_PAGES); > -       if ((long)ret < 0) > -               ret = global_page_state(NR_UNSTABLE_NFS) + > -                       global_page_state(NR_WRITEBACK); > - > -       return ret; > -} > - Nice cleanup. >  /* >  * couple the period to the dirty_ratio: >  * > @@ -703,12 +691,25 @@ void balance_dirty_pages_ratelimited_nr(struct address_space *mapping, >  } >  EXPORT_SYMBOL(balance_dirty_pages_ratelimited_nr); > > -void throttle_vm_writeout(gfp_t gfp_mask) > +/* > + * Throttle the current task if it is near dirty memory usage limits. > + * If @mem_cgroup is NULL or the root_cgroup, then use global dirty memory > + * information; otherwise use the per-memcg dirty limits. > + */ > +void throttle_vm_writeout(gfp_t gfp_mask, struct mem_cgroup *mem_cgroup) >  { >        struct dirty_info dirty_info; > +       unsigned long nr_writeback; > >         for ( ; ; ) { > -               global_dirty_info(&dirty_info); > +               if (!mem_cgroup || !memcg_dirty_info(mem_cgroup, &dirty_info)) { > +                       global_dirty_info(&dirty_info); > +                       nr_writeback = global_page_state(NR_UNSTABLE_NFS) + > +                               global_page_state(NR_WRITEBACK); > +               } else { > +                       nr_writeback = mem_cgroup_page_stat( > +                               mem_cgroup, MEMCG_NR_DIRTY_WRITEBACK_PAGES); In point of view rcu_read_lock removal, memcg can't destroy due to mem_cgroup_select_victim's css_tryget? Then, we can remove unnecessary rcu_read_lock in mem_cgroup_page_stat. -- Kind regards, Minchan Kim