From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with SMTP id 383198D003B for ; Thu, 21 Apr 2011 00:10:16 -0400 (EDT) Date: Thu, 21 Apr 2011 12:10:11 +0800 From: Wu Fengguang Subject: Re: [PATCH 3/6] writeback: sync expired inodes first in background writeback Message-ID: <20110421041010.GA18710@localhost> References: <20110419030532.515923886@intel.com> <20110419073523.GF23985@dastard> <20110419095740.GC5257@quack.suse.cz> <20110419125616.GA20059@localhost> <20110420012120.GK23985@dastard> <20110420025321.GA14398@localhost> <20110421004547.GD1814@dastard> <20110421020617.GB12191@localhost> <20110421030152.GG1814@dastard> <20110421035954.GA15461@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110421035954.GA15461@localhost> Sender: owner-linux-mm@kvack.org List-ID: To: Dave Chinner Cc: Jan Kara , Andrew Morton , Mel Gorman , Mel Gorman , Trond Myklebust , Itaru Kitayama , Minchan Kim , LKML , "linux-fsdevel@vger.kernel.org" , Linux Memory Management List > > Still, given wb_writeback() is the only caller of both > > __writeback_inodes_sb and writeback_inodes_wb(), I'm wondering if > > moving the queue_io calls up into wb_writeback() would clean up this > > logic somewhat. I think Jan mentioned doing something like this as > > well elsewhere in the thread... > > Unfortunately they call queue_io() inside the lock.. OK, let's try moving up the lock too. Do you like this change? :) Thanks, Fengguang --- fs/fs-writeback.c | 22 ++++++---------------- mm/backing-dev.c | 4 ++++ 2 files changed, 10 insertions(+), 16 deletions(-) --- linux-next.orig/fs/fs-writeback.c 2011-04-21 12:04:02.000000000 +0800 +++ linux-next/fs/fs-writeback.c 2011-04-21 12:05:54.000000000 +0800 @@ -591,7 +591,6 @@ void writeback_inodes_wb(struct bdi_writ if (!wbc->wb_start) wbc->wb_start = jiffies; /* livelock avoidance */ - spin_lock(&inode_wb_list_lock); if (list_empty(&wb->b_io)) queue_io(wb, wbc); @@ -610,22 +609,9 @@ void writeback_inodes_wb(struct bdi_writ if (ret) break; } - spin_unlock(&inode_wb_list_lock); /* Leave any unwritten inodes on b_io */ } -static void __writeback_inodes_sb(struct super_block *sb, - struct bdi_writeback *wb, struct writeback_control *wbc) -{ - WARN_ON(!rwsem_is_locked(&sb->s_umount)); - - spin_lock(&inode_wb_list_lock); - if (list_empty(&wb->b_io)) - queue_io(wb, wbc); - writeback_sb_inodes(sb, wb, wbc, true); - spin_unlock(&inode_wb_list_lock); -} - static inline bool over_bground_thresh(void) { unsigned long background_thresh, dirty_thresh; @@ -652,7 +638,7 @@ static unsigned long writeback_chunk_siz * The intended call sequence for WB_SYNC_ALL writeback is: * * wb_writeback() - * __writeback_inodes_sb() <== called only once + * writeback_sb_inodes() <== called only once * write_cache_pages() <== called once for each inode * (quickly) tag currently dirty pages * (maybe slowly) sync all tagged pages @@ -742,10 +728,14 @@ static long wb_writeback(struct bdi_writ retry: trace_wbc_writeback_start(&wbc, wb->bdi); + spin_lock(&inode_wb_list_lock); + if (list_empty(&wb->b_io)) + queue_io(wb, wbc); if (work->sb) - __writeback_inodes_sb(work->sb, wb, &wbc); + writeback_sb_inodes(work->sb, wb, &wbc, true); else writeback_inodes_wb(wb, &wbc); + spin_unlock(&inode_wb_list_lock); trace_wbc_writeback_written(&wbc, wb->bdi); bdi_update_write_bandwidth(wb->bdi, wbc.wb_start); --- linux-next.orig/mm/backing-dev.c 2011-04-21 12:06:02.000000000 +0800 +++ linux-next/mm/backing-dev.c 2011-04-21 12:06:31.000000000 +0800 @@ -268,7 +268,11 @@ static void bdi_flush_io(struct backing_ .nr_to_write = 1024, }; + spin_lock(&inode_wb_list_lock); + if (list_empty(&wb->b_io)) + queue_io(wb, wbc); writeback_inodes_wb(&bdi->wb, &wbc); + spin_unlock(&inode_wb_list_lock); } /* -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org