Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756174AbaGaFco (ORCPT ); Thu, 31 Jul 2014 01:32:44 -0400 Received: from mailout3.samsung.com ([203.254.224.33]:11743 "EHLO mailout3.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756144AbaGaFcm (ORCPT ); Thu, 31 Jul 2014 01:32:42 -0400 X-AuditID: cbfee61b-f79f86d00000144c-b7-53d9d4f82e67 From: Chao Yu To: "'Changman Lee'" , "'Jaegeuk Kim'" Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net References: <003901cf96ad$dbd17680$93746380$@samsung.com> <00f601cfabf7$691af580$3b50e080$@samsung.com> <20140731020708.GB24081@lcm> In-reply-to: <20140731020708.GB24081@lcm> Subject: RE: [f2fs-dev] [PATCH] f2fs: reduce competition among node page writes Date: Thu, 31 Jul 2014 13:31:46 +0800 Message-id: <016201cfac80$d6e336c0$84a9a440$@samsung.com> MIME-version: 1.0 Content-type: text/plain; charset=us-ascii Content-transfer-encoding: 7bit X-Mailer: Microsoft Outlook 14.0 Content-language: zh-cn Thread-index: AQIDqdX3kbhQL0bQPBsk1Qmt1GnMiAL7I+IyARKYY8ObMRsn0A== X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFvrALMWRmVeSWpSXmKPExsVy+t9jQd0fV24GG5xsMra4tq+RyeLJ+lnM FpcWuVvs2XuSxeLyrjlsDqwem1Z1snnsXvCZyaNvyypGj8+b5AJYorhsUlJzMstSi/TtErgy Pu9dx1zwSb9i3ZETLA2Mv1W7GDk5JARMJJ6uuMkOYYtJXLi3nq2LkYtDSGA6o8TMSzuZIZwf jBLTJu5gAaliE1CRWN7xn6mLkYNDRMBP4ma7PUiYWSBTYs7ryawQ9W2MEofPTWQGSXAKaEr0 zjwCZgsL+EvMnzabCcRmEVCVODtpFpjNK2Ap8enjXBYIW1Dix+R7LBBDtSTW7zzOBGHLS2xe 85YZ4lIFiR1nXzNCxMUlNh65BVYvIuAkcXrCGtYJjEKzkIyahWTULCSjZiFpX8DIsopRNLUg uaA4KT3XSK84Mbe4NC9dLzk/dxMjOB6eSe9gXNVgcYhRgINRiYf3h8nNYCHWxLLiytxDjBIc zEoivAcXAIV4UxIrq1KL8uOLSnNSiw8xSnOwKInzHmy1DhQSSE8sSc1OTS1ILYLJMnFwSjUw Tj+5124Ps27G3w1rkwymGcg4aOZe52Gv4DNjOORreFRa5IkPd49uNd9BWcFPKp0bm3WWTnix Rr7jW5fz80qfnenuQR61lxNlOb3rtG6bSYWHLfGNnz55q/FCdonlf/eyvjTTE9SYd0/3P8/+ uM1TmvLcare8uKLbunrJ+thLi8/IPr78seiXEktxRqKhFnNRcSIASwpSpYMCAAA= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Changman, > -----Original Message----- > From: Changman Lee [mailto:cm224.lee@samsung.com] > Sent: Thursday, July 31, 2014 10:07 AM > To: Chao Yu > Cc: 'Jaegeuk Kim'; linux-fsdevel@vger.kernel.org; linux-kernel@vger.kernel.org; > linux-f2fs-devel@lists.sourceforge.net > Subject: Re: [f2fs-dev] [PATCH] f2fs: reduce competition among node page writes > > Hi Chao, > > On Wed, Jul 30, 2014 at 09:07:49PM +0800, Chao Yu wrote: > > Hi Jaegeuk Changman, > > > > > -----Original Message----- > > > From: Chao Yu [mailto:chao2.yu@samsung.com] > > > Sent: Thursday, July 03, 2014 6:59 PM > > > To: Jaegeuk Kim; Changman Lee > > > Cc: linux-fsdevel@vger.kernel.org; linux-kernel@vger.kernel.org; > > > linux-f2fs-devel@lists.sourceforge.net > > > Subject: [f2fs-dev] [PATCH] f2fs: reduce competition among node page writes > > > > > > We do not need to block on ->node_write among different node page writers e.g. > > > fsync/flush, unless we have a node page writer from write_checkpoint. > > > So it's better use rw_semaphore instead of mutex type for ->node_write to > > > promote performance. > > > > If you could have time to help explaining the problem of this patch, I will be > > appreciated for that. > > I have no clue. Except checkpoint, I don't know why need to block to > write node page. > Do you have any problem when you test with this patch? I don't have. I send this patch about one month ago, but got no respond. So I want to ask if any problem in this patch or forget to look at this patch? To Jaegeuk: Any idea about this patch? > > > > > Another question is what is ->writepages in sbi used for? I'm not quite clear. > > > > I remember it is for writing data pages per thread as much as possible. > When multi-threads write some files simultaneously, multi-threads contended with > each other to allocate a block. So block allocation was interleaved > across threads. It makes fragmentation of file. Thank you for the explanation! :) I think what you say is reasonable. Previously I tested without this lock, although I found that the blocks written _almost_ were continuous in each '->writepages()'. Still I think we can gain more from readahead continuous block when using this lock, rather than remove it for promoting concurrent of writers. Thanks, Yu > > Thanks, > > > Thanks, > > > > > > > > Signed-off-by: Chao Yu > > > --- > > > fs/f2fs/checkpoint.c | 6 +++--- > > > fs/f2fs/f2fs.h | 2 +- > > > fs/f2fs/node.c | 4 ++-- > > > fs/f2fs/super.c | 2 +- > > > 4 files changed, 7 insertions(+), 7 deletions(-) > > > > > > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c > > > index 0b4710c..eec406b 100644 > > > --- a/fs/f2fs/checkpoint.c > > > +++ b/fs/f2fs/checkpoint.c > > > @@ -714,10 +714,10 @@ retry_flush_dents: > > > * until finishing nat/sit flush. > > > */ > > > retry_flush_nodes: > > > - mutex_lock(&sbi->node_write); > > > + down_write(&sbi->node_write); > > > > > > if (get_pages(sbi, F2FS_DIRTY_NODES)) { > > > - mutex_unlock(&sbi->node_write); > > > + up_write(&sbi->node_write); > > > sync_node_pages(sbi, 0, &wbc); > > > goto retry_flush_nodes; > > > } > > > @@ -726,7 +726,7 @@ retry_flush_nodes: > > > > > > static void unblock_operations(struct f2fs_sb_info *sbi) > > > { > > > - mutex_unlock(&sbi->node_write); > > > + up_write(&sbi->node_write); > > > f2fs_unlock_all(sbi); > > > } > > > > > > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > > > index ae3b4ac..ca30b5a 100644 > > > --- a/fs/f2fs/f2fs.h > > > +++ b/fs/f2fs/f2fs.h > > > @@ -444,7 +444,7 @@ struct f2fs_sb_info { > > > struct inode *meta_inode; /* cache meta blocks */ > > > struct mutex cp_mutex; /* checkpoint procedure lock */ > > > struct rw_semaphore cp_rwsem; /* blocking FS operations */ > > > - struct mutex node_write; /* locking node writes */ > > > + struct rw_semaphore node_write; /* locking node writes */ > > > struct mutex writepages; /* mutex for writepages() */ > > > bool por_doing; /* recovery is doing or not */ > > > wait_queue_head_t cp_wait; > > > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c > > > index a90f51d..7b5b5de 100644 > > > --- a/fs/f2fs/node.c > > > +++ b/fs/f2fs/node.c > > > @@ -1231,12 +1231,12 @@ static int f2fs_write_node_page(struct page *page, > > > if (wbc->for_reclaim) > > > goto redirty_out; > > > > > > - mutex_lock(&sbi->node_write); > > > + down_read(&sbi->node_write); > > > set_page_writeback(page); > > > write_node_page(sbi, page, &fio, nid, ni.blk_addr, &new_addr); > > > set_node_addr(sbi, &ni, new_addr, is_fsync_dnode(page)); > > > dec_page_count(sbi, F2FS_DIRTY_NODES); > > > - mutex_unlock(&sbi->node_write); > > > + up_read(&sbi->node_write); > > > unlock_page(page); > > > return 0; > > > > > > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c > > > index 8f96d93..bed9413 100644 > > > --- a/fs/f2fs/super.c > > > +++ b/fs/f2fs/super.c > > > @@ -947,7 +947,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent) > > > mutex_init(&sbi->gc_mutex); > > > mutex_init(&sbi->writepages); > > > mutex_init(&sbi->cp_mutex); > > > - mutex_init(&sbi->node_write); > > > + init_rwsem(&sbi->node_write); > > > sbi->por_doing = false; > > > spin_lock_init(&sbi->stat_lock); > > > > > > -- > > > 1.7.9.5 > > > > > > > > > > > > ------------------------------------------------------------------------------ > > > Open source business process management suite built on Java and Eclipse > > > Turn processes into business applications with Bonita BPM Community Edition > > > Quickly connect people, data, and systems into organized workflows > > > Winner of BOSSIE, CODIE, OW2 and Gartner awards > > > http://p.sf.net/sfu/Bonitasoft > > > _______________________________________________ > > > Linux-f2fs-devel mailing list > > > Linux-f2fs-devel@lists.sourceforge.net > > > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel -- 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/