From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with ESMTP id E0DA56B0047 for ; Thu, 4 Feb 2010 00:18:37 -0500 (EST) Date: Thu, 4 Feb 2010 14:09:42 +0900 From: Daisuke Nishimura Subject: Re: [PATCH -mmotm 7/8] memcg: move charges of anonymous swap Message-Id: <20100204140942.0ef6d7b1.nishimura@mxp.nes.nec.co.jp> In-Reply-To: <20100203193127.fe5efa17.akpm@linux-foundation.org> References: <20091221143106.6ff3ca15.nishimura@mxp.nes.nec.co.jp> <20091221143816.9794cd17.nishimura@mxp.nes.nec.co.jp> <20100203193127.fe5efa17.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Andrew Morton Cc: Balbir Singh , KAMEZAWA Hiroyuki , Li Zefan , Paul Menage , linux-mm , Daisuke Nishimura List-ID: On Wed, 3 Feb 2010 19:31:27 -0800, Andrew Morton wrote: > On Mon, 21 Dec 2009 14:38:16 +0900 Daisuke Nishimura wrote: > > > This patch is another core part of this move-charge-at-task-migration feature. > > It enables moving charges of anonymous swaps. > > > > To move the charge of swap, we need to exchange swap_cgroup's record. > > > > In current implementation, swap_cgroup's record is protected by: > > > > - page lock: if the entry is on swap cache. > > - swap_lock: if the entry is not on swap cache. > > > > This works well in usual swap-in/out activity. > > > > But this behavior make the feature of moving swap charge check many conditions > > to exchange swap_cgroup's record safely. > > > > So I changed modification of swap_cgroup's recored(swap_cgroup_record()) > > to use xchg, and define a new function to cmpxchg swap_cgroup's record. > > > > This patch also enables moving charge of non pte_present but not uncharged swap > > caches, which can be exist on swap-out path, by getting the target pages via > > find_get_page() as do_mincore() does. > > > > > > ... > > > > + else if (is_swap_pte(ptent)) { > > is_swap_pte() isn't implemented for CONFIG_MMU=n, so the build breaks. Ah, you're right. I'm sorry I don't have any evironment to test !CONFIG_MMU. Using #ifdef like below would be the simplest fix(SWAP is depend on MMU), but hmm, #ifdef is ugly. I'll prepare another fix. === From: Daisuke Nishimura build fix in !CONFIG_MMU case. Signed-off-by: Daisuke Nishimura --- mm/memcontrol.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 953b18b..85b48cb 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3635,6 +3635,7 @@ static int is_target_pte_for_mc(struct vm_area_struct *vma, &mc.to->move_charge_at_immigrate); if (!pte_present(ptent)) { +#ifdef CONFIG_SWAP /* TODO: handle swap of shmes/tmpfs */ if (pte_none(ptent) || pte_file(ptent)) return 0; @@ -3644,6 +3645,7 @@ static int is_target_pte_for_mc(struct vm_area_struct *vma, return 0; usage_count = mem_cgroup_count_swap_user(ent, &page); } +#endif } else { page = vm_normal_page(vma, addr, ptent); if (!page || !page_mapped(page)) -- 1.6.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org