Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756191Ab0G2JyW (ORCPT ); Thu, 29 Jul 2010 05:54:22 -0400 Received: from fgwmail7.fujitsu.co.jp ([192.51.44.37]:43015 "EHLO fgwmail7.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752151Ab0G2JyT (ORCPT ); Thu, 29 Jul 2010 05:54:19 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 Date: Thu, 29 Jul 2010 18:49:27 +0900 From: KAMEZAWA Hiroyuki To: KAMEZAWA Hiroyuki Cc: "linux-mm@kvack.org" , "balbir@linux.vnet.ibm.com" , "nishimura@mxp.nes.nec.co.jp" , vgoyal@redhat.com, m-ikeda@ds.jp.nec.com, gthelen@google.com, "akpm@linux-foundation.org" , "linux-kernel@vger.kernel.org" Subject: [PATCH 5/5] memcg : use spinlock in pcg instad of bit_spinlock Message-Id: <20100729184927.9a3e214d.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20100729184250.acdff587.kamezawa.hiroyu@jp.fujitsu.com> References: <20100729184250.acdff587.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: 3491 Lines: 118 From: KAMEZAWA Hiroyuki This patch replaces bit_spinlock with spinlock. In general, spinlock has good functinality 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. expected effects: - use better codes. - ticket lock on x86-64 - para-vitualization aware lock etc.. Chagelog: 20090729 - fixed page_cgroup_locked(). Signed-off-by: KAMEZAWA Hiroyuki -- --- include/linux/page_cgroup.h | 35 +++++++++++++++++++++++++++++++++-- mm/page_cgroup.c | 3 +++ 2 files changed, 36 insertions(+), 2 deletions(-) Index: mmotm-0727/include/linux/page_cgroup.h =================================================================== --- mmotm-0727.orig/include/linux/page_cgroup.h +++ mmotm-0727/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; @@ -36,7 +42,9 @@ struct page_cgroup *lookup_page_cgroup(s enum { /* flags for mem_cgroup */ - PCG_LOCK, /* page cgroup is locked */ +#ifndef PCG_HAS_SPINLOCK + PCG_LOCK, /* page cgroup is locked (see below also.)*/ +#endif PCG_CACHE, /* charged as cache */ PCG_USED, /* this object is in use. */ PCG_ACCT_LRU, /* page has been accounted for */ @@ -60,7 +68,7 @@ static inline void ClearPageCgroup##unam static inline int TestClearPageCgroup##uname(struct page_cgroup *pc) \ { return test_and_clear_bit(PCG_##lname, &pc->flags); } -TESTPCGFLAG(Locked, LOCK) + /* Cache flag is set only once (at allocation) */ TESTPCGFLAG(Cache, CACHE) @@ -90,6 +98,22 @@ 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); +} + +static inline bool page_cgroup_locked(struct page_cgroup *pc) +{ + return spin_is_locked(&pc->lock); +} + +#else static inline void lock_page_cgroup(struct page_cgroup *pc) { bit_spin_lock(PCG_LOCK, &pc->flags); @@ -100,6 +124,13 @@ static inline void unlock_page_cgroup(st bit_spin_unlock(PCG_LOCK, &pc->flags); } +static inline bool page_cgroup_locked(struct page_cgroup *pc) +{ + return test_bit(PCG_LOCK, &pc->flags); +} + +#endif + static inline void SetPCGFileFlag(struct page_cgroup *pc, int idx) { set_bit(PCG_FILE_FLAGS + idx, &pc->flags); Index: mmotm-0727/mm/page_cgroup.c =================================================================== --- mmotm-0727.orig/mm/page_cgroup.c +++ mmotm-0727/mm/page_cgroup.c @@ -18,6 +18,9 @@ __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/