From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with SMTP id 968AB6B004F for ; Wed, 27 May 2009 02:51:44 -0400 (EDT) Received: from m6.gw.fujitsu.co.jp ([10.0.50.76]) by fgwmail6.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id n4R6qUFw004636 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Wed, 27 May 2009 15:52:31 +0900 Received: from smail (m6 [127.0.0.1]) by outgoing.m6.gw.fujitsu.co.jp (Postfix) with ESMTP id 5DC3A45DD72 for ; Wed, 27 May 2009 15:52:30 +0900 (JST) Received: from s6.gw.fujitsu.co.jp (s6.gw.fujitsu.co.jp [10.0.50.96]) by m6.gw.fujitsu.co.jp (Postfix) with ESMTP id 320F0266CC2 for ; Wed, 27 May 2009 15:52:30 +0900 (JST) Received: from s6.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s6.gw.fujitsu.co.jp (Postfix) with ESMTP id 3B9BDE18009 for ; Wed, 27 May 2009 15:52:29 +0900 (JST) Received: from m106.s.css.fujitsu.com (m106.s.css.fujitsu.com [10.249.87.106]) by s6.gw.fujitsu.co.jp (Postfix) with ESMTP id A0A6C1DB803E for ; Wed, 27 May 2009 15:52:28 +0900 (JST) Date: Wed, 27 May 2009 15:50:55 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [RFC][PATCH 5/5] (experimental) chase and free cache only swap Message-Id: <20090527155055.2dcee5ce.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20090527153024.bb275962.nishimura@mxp.nes.nec.co.jp> References: <20090526121259.b91b3e9d.kamezawa.hiroyu@jp.fujitsu.com> <20090526121834.dd9a4193.kamezawa.hiroyu@jp.fujitsu.com> <20090527141442.d191dc2d.kamezawa.hiroyu@jp.fujitsu.com> <20090527153024.bb275962.nishimura@mxp.nes.nec.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Daisuke Nishimura Cc: "linux-mm@kvack.org" , "balbir@linux.vnet.ibm.com" , "hugh.dickins@tiscali.co.uk" , "hannes@cmpxchg.org" , "linux-kernel@vger.kernel.org" List-ID: On Wed, 27 May 2009 15:30:24 +0900 Daisuke Nishimura wrote: > 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 ;) > Oh, will be fixed in the next post :( > 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. > Yes, Hot-to-test is my concern, too.. Thanks, -Kame > > 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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