From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422925AbXCGRSc (ORCPT ); Wed, 7 Mar 2007 12:18:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1422919AbXCGRSb (ORCPT ); Wed, 7 Mar 2007 12:18:31 -0500 Received: from cantor2.suse.de ([195.135.220.15]:43850 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1422924AbXCGRS2 (ORCPT ); Wed, 7 Mar 2007 12:18:28 -0500 Message-Id: <20070307171650.864004527@mini.kroah.org> References: <20070307171035.150802805@mini.kroah.org> User-Agent: quilt/0.45-1 Date: Wed, 07 Mar 2007 09:12:10 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org, torvalds@linux-foundation.org Cc: Justin Forbes , Zwane Mwaikambo , "Theodore Ts'o" , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, nickpiggin@yahoo.com.au, galak@kernel.crashing.org, zaitcev@redhat.com, hirofumi@mail.parknet.co.jp Subject: [patch 095/101] throttle_vm_writeout(): dont loop on GFP_NOFS and GFP_NOIO allocations Content-Disposition: inline; filename=throttle_vm_writeout-don-t-loop-on-gfp_nofs-and-gfp_noio-allocations.patch Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org From: Andrew Morton throttle_vm_writeout() is designed to wait for the dirty levels to subside. But if the caller holds IO or FS locks, we might be holding up that writeout. So change it to take a single nap to give other devices a chance to clean some memory, then return. Cc: Nick Piggin Cc: OGAWA Hirofumi Cc: Kumar Gala Cc: Pete Zaitcev Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- include/linux/writeback.h | 2 +- mm/page-writeback.c | 13 +++++++++++-- mm/vmscan.c | 2 +- 3 files changed, 13 insertions(+), 4 deletions(-) --- linux-2.6.20.1.orig/include/linux/writeback.h +++ linux-2.6.20.1/include/linux/writeback.h @@ -84,7 +84,7 @@ static inline void wait_on_inode(struct int wakeup_pdflush(long nr_pages); void laptop_io_completion(void); void laptop_sync_completion(void); -void throttle_vm_writeout(void); +void throttle_vm_writeout(gfp_t gfp_mask); /* These are exported to sysctl. */ extern int dirty_background_ratio; --- linux-2.6.20.1.orig/mm/page-writeback.c +++ linux-2.6.20.1/mm/page-writeback.c @@ -296,11 +296,21 @@ void balance_dirty_pages_ratelimited_nr( } EXPORT_SYMBOL(balance_dirty_pages_ratelimited_nr); -void throttle_vm_writeout(void) +void throttle_vm_writeout(gfp_t gfp_mask) { long background_thresh; long dirty_thresh; + if ((gfp_mask & (__GFP_FS|__GFP_IO)) != (__GFP_FS|__GFP_IO)) { + /* + * The caller might hold locks which can prevent IO completion + * or progress in the filesystem. So we cannot just sit here + * waiting for IO to complete. + */ + congestion_wait(WRITE, HZ/10); + return; + } + for ( ; ; ) { get_dirty_limits(&background_thresh, &dirty_thresh, NULL); @@ -317,7 +327,6 @@ void throttle_vm_writeout(void) } } - /* * writeback at least _min_pages, and keep writing until the amount of dirty * memory is less than the background threshold, or until we're all clean. --- linux-2.6.20.1.orig/mm/vmscan.c +++ linux-2.6.20.1/mm/vmscan.c @@ -949,7 +949,7 @@ static unsigned long shrink_zone(int pri } } - throttle_vm_writeout(); + throttle_vm_writeout(sc->gfp_mask); atomic_dec(&zone->reclaim_in_progress); return nr_reclaimed; --