From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with ESMTP id F27D66B004A for ; Thu, 30 Jun 2011 19:57:21 -0400 (EDT) Received: from m3.gw.fujitsu.co.jp (unknown [10.0.50.73]) by fgwmail5.fujitsu.co.jp (Postfix) with ESMTP id 806AA3EE0BD for ; Fri, 1 Jul 2011 08:57:18 +0900 (JST) Received: from smail (m3 [127.0.0.1]) by outgoing.m3.gw.fujitsu.co.jp (Postfix) with ESMTP id 5FD4045DEB4 for ; Fri, 1 Jul 2011 08:57:18 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (s3.gw.fujitsu.co.jp [10.0.50.93]) by m3.gw.fujitsu.co.jp (Postfix) with ESMTP id 39E2945DEAD for ; Fri, 1 Jul 2011 08:57:18 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 2C0FC1DB803F for ; Fri, 1 Jul 2011 08:57:18 +0900 (JST) Received: from ml13.s.css.fujitsu.com (ml13.s.css.fujitsu.com [10.240.81.133]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id E629F1DB803E for ; Fri, 1 Jul 2011 08:57:17 +0900 (JST) Date: Fri, 1 Jul 2011 08:50:13 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [PATCH] [Cleanup] memcg: export memory cgroup's swappiness v2 Message-Id: <20110701085013.4e8cbb02.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20110630130134.63a1dd37.akpm@linux-foundation.org> References: <20110629190325.28aa2dc6.kamezawa.hiroyu@jp.fujitsu.com> <20110630130134.63a1dd37.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 List-ID: To: Andrew Morton Cc: "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "nishimura@mxp.nes.nec.co.jp" , "bsingharora@gmail.com" , Michal Hocko , Ying Han On Thu, 30 Jun 2011 13:01:34 -0700 Andrew Morton wrote: > On Wed, 29 Jun 2011 19:03:25 +0900 > KAMEZAWA Hiroyuki wrote: > > > Each memory cgroup has 'swappiness' value and it can be accessed by > > get_swappiness(memcg). The major user is try_to_free_mem_cgroup_pages() > > and swappiness is passed by argument. It's propagated by scan_control. > > > > get_swappiness is static function but some planned updates will need to > > get swappiness from files other than memcontrol.c > > This patch exports get_swappiness() as mem_cgroup_swappiness(). > > By this, we can remove the argument of swapiness from try_to_free... > > and drop swappiness from scan_control. only memcg uses it. > > x86_64 allnoconfig (aka Documentation/SubmitChecklist, section 2b): > > mm/vmscan.c: In function 'vmscan_swappiness': > mm/vmscan.c:1734: error: implicit declaration of function 'mem_cgroup_swappiness' > > This is pretty broken. I think we do want to implement this for > CONFIG_CGROUP_MEM_RES_CTLR=y, CONFIG_SWAP=n: > > --- a/include/linux/swap.h~memcg-export-memory-cgroups-swappiness-fix > +++ a/include/linux/swap.h > @@ -365,17 +365,12 @@ static inline void put_swap_token(struct > extern void > mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout); > extern int mem_cgroup_count_swap_user(swp_entry_t ent, struct page **pagep); > -extern unsigned int mem_cgroup_swappiness(struct mem_cgroup *mem); > #else > static inline void > mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout) > { > } > > -static inline unsigned int mem_cgroup_swappiness(struct mem_cgroup *mem) > -{ > - return vm_swappiness; > -} > #endif > #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP > extern void mem_cgroup_uncharge_swap(swp_entry_t ent); > @@ -510,5 +505,15 @@ mem_cgroup_count_swap_user(swp_entry_t e > #endif > > #endif /* CONFIG_SWAP */ > + > +#ifdef CONFIG_CGROUP_MEM_RES_CTLR > +extern unsigned int mem_cgroup_swappiness(struct mem_cgroup *mem); > +#else > +static inline unsigned int mem_cgroup_swappiness(struct mem_cgroup *mem) > +{ > + return vm_swappiness; > +} > +#endif > + > #endif /* __KERNEL__*/ > #endif /* _LINUX_SWAP_H */ > > But what is the role of CONFIG_CGROUP_MEM_RES_CTLR_SWAP? > > And in the above circumstances, vmscan_swappiness() devolves into > > static int vmscan_swappiness(struct scan_control *sc) > { > if (scanning_global_lru(sc)) > return vm_swappiness; > return vm_swappiness; > } > > which I guess makes sense but seems a bit odd. > > Anyway, my confidence level is low so I think I'll drop this patch. > Please have a think about the interplay between > CONFIG_CGROUP_MEM_RES_CTLR, CONFIG_CGROUP_MEM_RES_CTLR_SWAP and > CONFIG_SWAP. > > Ok, I'll check it. Maybe I miss !CONFIG_SWAP... Thanks, -Kame -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org