Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755746Ab0G0IHV (ORCPT ); Tue, 27 Jul 2010 04:07:21 -0400 Received: from fgwmail7.fujitsu.co.jp ([192.51.44.37]:36038 "EHLO fgwmail7.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755476Ab0G0IHP (ORCPT ); Tue, 27 Jul 2010 04:07:15 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 Date: Tue, 27 Jul 2010 17:02:25 +0900 From: KAMEZAWA Hiroyuki To: KAMEZAWA Hiroyuki Cc: "linux-mm@kvack.org" , "nishimura@mxp.nes.nec.co.jp" , "balbir@linux.vnet.ibm.com" , gthelen@google.com, m-ikeda@ds.jp.nec.com, "akpm@linux-foundation.org" , "linux-kernel@vger.kernel.org" Subject: [RFC][PATCH 7/7][memcg] use spin lock instead of bit_spin_lock in page_cgroup Message-Id: <20100727170225.64f78b15.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20100727165155.8b458b7f.kamezawa.hiroyu@jp.fujitsu.com> References: <20100727165155.8b458b7f.kamezawa.hiroyu@jp.fujitsu.com> Organization: FUJITSU Co. LTD. X-Mailer: Sylpheed 3.0.3 (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 Content-Length: 2259 Lines: 73 From: KAMEZAWA Hiroyuki This patch replaces page_cgroup's bit_spinlock with spinlock. In general, spinlock has good implementation than bit_spin_lock and we should use it if we have a room for it. In 64bit arch, we have extra 4bytes. Let's use it. Signed-off-by: KAMEZAWA Hiroyuki -- Index: mmotm-0719/include/linux/page_cgroup.h =================================================================== --- mmotm-0719.orig/include/linux/page_cgroup.h +++ mmotm-0719/include/linux/page_cgroup.h @@ -10,8 +10,14 @@ * All page cgroups are allocated at boot or memory hotplug event, * then the page cgroup for pfn always exists. */ +#ifdef CONFIG_64BIT +#define PCG_HAS_SPINLOCK +#endif struct page_cgroup { unsigned long flags; +#ifdef PCG_HAS_SPINLOCK + spinlock_t lock; +#endif unsigned short mem_cgroup; /* ID of assigned memory cgroup */ unsigned short blk_cgroup; /* Not Used..but will be. */ struct page *page; @@ -90,6 +96,16 @@ static inline enum zone_type page_cgroup return page_zonenum(pc->page); } +#ifdef PCG_HAS_SPINLOCK +static inline void lock_page_cgroup(struct page_cgroup *pc) +{ + spin_lock(&pc->lock); +} +static inline void unlock_page_cgroup(struct page_cgroup *pc) +{ + spin_unlock(&pc->lock); +} +#else static inline void lock_page_cgroup(struct page_cgroup *pc) { bit_spin_lock(PCG_LOCK, &pc->flags); @@ -99,6 +115,7 @@ static inline void unlock_page_cgroup(st { bit_spin_unlock(PCG_LOCK, &pc->flags); } +#endif static inline void SetPCGFileFlag(struct page_cgroup *pc, int idx) { Index: mmotm-0719/mm/page_cgroup.c =================================================================== --- mmotm-0719.orig/mm/page_cgroup.c +++ mmotm-0719/mm/page_cgroup.c @@ -17,6 +17,9 @@ __init_page_cgroup(struct page_cgroup *p pc->mem_cgroup = 0; pc->page = pfn_to_page(pfn); INIT_LIST_HEAD(&pc->lru); +#ifdef PCG_HAS_SPINLOCK + spin_lock_init(&pc->lock); +#endif } static unsigned long total_usage; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/