From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760754AbZE0Gp7 (ORCPT ); Wed, 27 May 2009 02:45:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751040AbZE0Gpw (ORCPT ); Wed, 27 May 2009 02:45:52 -0400 Received: from TYO202.gate.nec.co.jp ([202.32.8.206]:64447 "EHLO tyo202.gate.nec.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757902AbZE0Gpw (ORCPT ); Wed, 27 May 2009 02:45:52 -0400 Date: Wed, 27 May 2009 15:30:24 +0900 From: Daisuke Nishimura To: KAMEZAWA Hiroyuki Cc: "linux-mm@kvack.org" , "balbir@linux.vnet.ibm.com" , "hugh.dickins@tiscali.co.uk" , "hannes@cmpxchg.org" , "linux-kernel@vger.kernel.org" , Daisuke Nishimura Subject: Re: [RFC][PATCH 5/5] (experimental) chase and free cache only swap Message-Id: <20090527153024.bb275962.nishimura@mxp.nes.nec.co.jp> In-Reply-To: <20090527141442.d191dc2d.kamezawa.hiroyu@jp.fujitsu.com> References: <20090526121259.b91b3e9d.kamezawa.hiroyu@jp.fujitsu.com> <20090526121834.dd9a4193.kamezawa.hiroyu@jp.fujitsu.com> <20090527141442.d191dc2d.kamezawa.hiroyu@jp.fujitsu.com> Organization: NEC Soft, Ltd. X-Mailer: Sylpheed 2.6.0 (GTK+ 2.10.14; i686-pc-mingw32) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 27 May 2009 14:14:42 +0900, KAMEZAWA Hiroyuki wrote: > On Tue, 26 May 2009 12:18:34 +0900 > KAMEZAWA Hiroyuki wrote: > > > > > From: KAMEZAWA Hiroyuki > > > This is a replacement for this. (just an idea, not testd.) > > I think this works well. Does anyone has concerns ? I think so too, except some trivial build errors ;) I'll test it, but it will take a long time to see the effect of this patch even if setting the swap space to reasonable size. Thanks, Daisuke Nishimura. > Do I have to modify swap-cluster code to do this in sane way ? > > --- > mm/swapfile.c | 40 ++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 40 insertions(+) > > Index: new-trial-swapcount/mm/swapfile.c > =================================================================== > --- new-trial-swapcount.orig/mm/swapfile.c > +++ new-trial-swapcount/mm/swapfile.c > @@ -74,6 +74,26 @@ static inline unsigned short make_swap_c > return ret; > } > > +static int try_to_reuse_swap(struct swap_info_struct *si, unsigned long offset) > +{ > + int type = si - swap_info; > + swp_entry_t entry = swp_entry(type, offset); > + struct page *page; > + > + page = find_get_page(page); > + if (!page) > + return 0; > + if (!trylock_page(page)) { > + page_cache_release(page); > + return 0; > + } > + try_to_free_swap(page); > + unlock_page(page); > + page_cache_release(page); > + return 1; > +} > + > + > /* > * We need this because the bdev->unplug_fn can sleep and we cannot > * hold swap_lock while calling the unplug_fn. And swap_lock > @@ -295,6 +315,18 @@ checks: > goto no_page; > if (offset > si->highest_bit) > scan_base = offset = si->lowest_bit; > + > + /* reuse swap entry of cache-only swap if not busy. */ > + if (vm_swap_full() && si->swap_map[offset] == SWAP_HAS_CACHE) { > + int ret; > + spin_unlock(&swap_lock); > + ret = try_to_reuse_swap(si, offset)); > + spin_lock(&swap_lock); > + if (ret) > + goto checks; /* we released swap_lock */ > + goto scan; > + } > + > if (si->swap_map[offset]) > goto scan; > > @@ -378,6 +410,10 @@ scan: > spin_lock(&swap_lock); > goto checks; > } > + if (vm_swap_full() && si->swap_map[offset] == SWAP_HAS_CACHE) { > + spin_lock(&swap_lock); > + goto checks; > + } > if (unlikely(--latency_ration < 0)) { > cond_resched(); > latency_ration = LATENCY_LIMIT; > @@ -389,6 +425,10 @@ scan: > spin_lock(&swap_lock); > goto checks; > } > + if (vm_swap_full() && si->swap_map[offset] == SWAP_HAS_CACHE) { > + spin_lock(&swap_lock); > + goto checks; > + } > if (unlikely(--latency_ration < 0)) { > cond_resched(); > latency_ration = LATENCY_LIMIT; > 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 3B3236B004F for ; Wed, 27 May 2009 02:45:05 -0400 (EDT) Date: Wed, 27 May 2009 15:30:24 +0900 From: Daisuke Nishimura Subject: Re: [RFC][PATCH 5/5] (experimental) chase and free cache only swap Message-Id: <20090527153024.bb275962.nishimura@mxp.nes.nec.co.jp> In-Reply-To: <20090527141442.d191dc2d.kamezawa.hiroyu@jp.fujitsu.com> References: <20090526121259.b91b3e9d.kamezawa.hiroyu@jp.fujitsu.com> <20090526121834.dd9a4193.kamezawa.hiroyu@jp.fujitsu.com> <20090527141442.d191dc2d.kamezawa.hiroyu@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: "linux-mm@kvack.org" , "balbir@linux.vnet.ibm.com" , "hugh.dickins@tiscali.co.uk" , "hannes@cmpxchg.org" , "linux-kernel@vger.kernel.org" , Daisuke Nishimura List-ID: On Wed, 27 May 2009 14:14:42 +0900, KAMEZAWA Hiroyuki wrote: > On Tue, 26 May 2009 12:18:34 +0900 > KAMEZAWA Hiroyuki wrote: > > > > > From: KAMEZAWA Hiroyuki > > > This is a replacement for this. (just an idea, not testd.) > > I think this works well. Does anyone has concerns ? I think so too, except some trivial build errors ;) I'll test it, but it will take a long time to see the effect of this patch even if setting the swap space to reasonable size. Thanks, Daisuke Nishimura. > Do I have to modify swap-cluster code to do this in sane way ? > > --- > mm/swapfile.c | 40 ++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 40 insertions(+) > > Index: new-trial-swapcount/mm/swapfile.c > =================================================================== > --- new-trial-swapcount.orig/mm/swapfile.c > +++ new-trial-swapcount/mm/swapfile.c > @@ -74,6 +74,26 @@ static inline unsigned short make_swap_c > return ret; > } > > +static int try_to_reuse_swap(struct swap_info_struct *si, unsigned long offset) > +{ > + int type = si - swap_info; > + swp_entry_t entry = swp_entry(type, offset); > + struct page *page; > + > + page = find_get_page(page); > + if (!page) > + return 0; > + if (!trylock_page(page)) { > + page_cache_release(page); > + return 0; > + } > + try_to_free_swap(page); > + unlock_page(page); > + page_cache_release(page); > + return 1; > +} > + > + > /* > * We need this because the bdev->unplug_fn can sleep and we cannot > * hold swap_lock while calling the unplug_fn. And swap_lock > @@ -295,6 +315,18 @@ checks: > goto no_page; > if (offset > si->highest_bit) > scan_base = offset = si->lowest_bit; > + > + /* reuse swap entry of cache-only swap if not busy. */ > + if (vm_swap_full() && si->swap_map[offset] == SWAP_HAS_CACHE) { > + int ret; > + spin_unlock(&swap_lock); > + ret = try_to_reuse_swap(si, offset)); > + spin_lock(&swap_lock); > + if (ret) > + goto checks; /* we released swap_lock */ > + goto scan; > + } > + > if (si->swap_map[offset]) > goto scan; > > @@ -378,6 +410,10 @@ scan: > spin_lock(&swap_lock); > goto checks; > } > + if (vm_swap_full() && si->swap_map[offset] == SWAP_HAS_CACHE) { > + spin_lock(&swap_lock); > + goto checks; > + } > if (unlikely(--latency_ration < 0)) { > cond_resched(); > latency_ration = LATENCY_LIMIT; > @@ -389,6 +425,10 @@ scan: > spin_lock(&swap_lock); > goto checks; > } > + if (vm_swap_full() && si->swap_map[offset] == SWAP_HAS_CACHE) { > + spin_lock(&swap_lock); > + goto checks; > + } > if (unlikely(--latency_ration < 0)) { > cond_resched(); > latency_ration = LATENCY_LIMIT; > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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