Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752849AbaG2MV5 (ORCPT ); Tue, 29 Jul 2014 08:21:57 -0400 Received: from mail.kernel.org ([198.145.19.201]:46703 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750828AbaG2MVz (ORCPT ); Tue, 29 Jul 2014 08:21:55 -0400 Date: Tue, 29 Jul 2014 05:22:15 -0700 From: Jaegeuk Kim To: Changman Lee Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Subject: Re: [f2fs-dev] [PATCH 07/11] f2fs: enable in-place-update for fdatasync Message-ID: <20140729122215.GB84378@jaegeuk-mac02> References: <1406328445-63707-1-git-send-email-jaegeuk@kernel.org> <1406328445-63707-7-git-send-email-jaegeuk@kernel.org> <20140729004111.GA442@lcm> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140729004111.GA442@lcm> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Changman, On Tue, Jul 29, 2014 at 09:41:11AM +0900, Changman Lee wrote: > Hi Jaegeuk, > > On Fri, Jul 25, 2014 at 03:47:21PM -0700, Jaegeuk Kim wrote: > > This patch enforces in-place-updates only when fdatasync is requested. > > If we adopt this in-place-updates for the fdatasync, we can skip to write the > > recovery information. > > But, as you know, random write occurs when changing into in-place-updates. > It will degrade write performance. Is there any case in-place-updates is > better, except recovery or high utilization? As I described, you can easily imagine, if users requested small amount of data writes with fdatasync, we should do data writes + node writes. But, if we can do in-place-update, we don't need to write node blocks. Surely it triggers random writes, however, the amount of data is preety small and the device handles them very fast by its inside cache, so that it can enhance the performance. Thanks, > > Thanks > > > > > Signed-off-by: Jaegeuk Kim > > --- > > fs/f2fs/f2fs.h | 1 + > > fs/f2fs/file.c | 7 +++++++ > > fs/f2fs/segment.h | 4 ++++ > > 3 files changed, 12 insertions(+) > > > > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > > index ab36025..8f8685e 100644 > > --- a/fs/f2fs/f2fs.h > > +++ b/fs/f2fs/f2fs.h > > @@ -998,6 +998,7 @@ enum { > > FI_INLINE_DATA, /* used for inline data*/ > > FI_APPEND_WRITE, /* inode has appended data */ > > FI_UPDATE_WRITE, /* inode has in-place-update data */ > > + FI_NEED_IPU, /* used fo ipu for fdatasync */ > > }; > > > > static inline void set_inode_flag(struct f2fs_inode_info *fi, int flag) > > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c > > index 121689a..e339856 100644 > > --- a/fs/f2fs/file.c > > +++ b/fs/f2fs/file.c > > @@ -127,11 +127,18 @@ int f2fs_sync_file(struct file *file, loff_t start, loff_t end, int datasync) > > return 0; > > > > trace_f2fs_sync_file_enter(inode); > > + > > + /* if fdatasync is triggered, let's do in-place-update */ > > + if (datasync) > > + set_inode_flag(fi, FI_NEED_IPU); > > + > > ret = filemap_write_and_wait_range(inode->i_mapping, start, end); > > if (ret) { > > trace_f2fs_sync_file_exit(inode, need_cp, datasync, ret); > > return ret; > > } > > + if (datasync) > > + clear_inode_flag(fi, FI_NEED_IPU); > > > > /* > > * if there is no written data, don't waste time to write recovery info. > > diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h > > index ee5c75e..55973f7 100644 > > --- a/fs/f2fs/segment.h > > +++ b/fs/f2fs/segment.h > > @@ -486,6 +486,10 @@ static inline bool need_inplace_update(struct inode *inode) > > if (S_ISDIR(inode->i_mode)) > > return false; > > > > + /* this is only set during fdatasync */ > > + if (is_inode_flag_set(F2FS_I(inode), FI_NEED_IPU)) > > + return true; > > + > > switch (SM_I(sbi)->ipu_policy) { > > case F2FS_IPU_FORCE: > > return true; > > -- > > 1.8.5.2 (Apple Git-48) > > > > > > ------------------------------------------------------------------------------ > > Want fast and easy access to all the code in your enterprise? Index and > > search up to 200,000 lines of code with a free copy of Black Duck > > Code Sight - the same software that powers the world's largest code > > search on Ohloh, the Black Duck Open Hub! Try it now. > > http://p.sf.net/sfu/bds > > _______________________________________________ > > 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/