From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932207Ab3KMDqJ (ORCPT ); Tue, 12 Nov 2013 22:46:09 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:25553 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1755874Ab3KMDpv (ORCPT ); Tue, 12 Nov 2013 22:45:51 -0500 X-IronPort-AV: E=Sophos;i="4.93,690,1378828800"; d="scan'208";a="9020141" Message-ID: <5282F46C.5040403@cn.fujitsu.com> Date: Wed, 13 Nov 2013 11:39:24 +0800 From: Gu Zheng User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:7.0.1) Gecko/20110930 Thunderbird/7.0.1 MIME-Version: 1.0 To: Chao Yu CC: ??? , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, =?GB2312?B?zLfmrQ==?= Subject: Re: [f2fs-dev] [PATCH 1/2] f2fs: add a new function to support for merging contiguous read References: <000001cedf66$46a9bb70$d3fd3250$@samsung.com> In-Reply-To: <000001cedf66$46a9bb70$d3fd3250$@samsung.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2013/11/13 11:43:54, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2013/11/13 11:43:56, Serialize complete at 2013/11/13 11:43:56 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=GB2312 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/12/2013 01:15 PM, Chao Yu wrote: > For better read performance, we add a new function to support for merging contiguous read as the one for write. Nice shot! > > Signed-off-by: Chao Yu Acked-by: Gu Zheng > --- > fs/f2fs/data.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ > fs/f2fs/f2fs.h | 2 ++ > 2 files changed, 47 insertions(+) > > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > index aa3438c..f30060b 100644 > --- a/fs/f2fs/data.c > +++ b/fs/f2fs/data.c > @@ -404,6 +404,51 @@ int f2fs_readpage(struct f2fs_sb_info *sbi, struct page *page, > return 0; > } > > +void f2fs_submit_read_bio(struct f2fs_sb_info *sbi, int rw) > +{ > + down_read(&sbi->bio_sem); > + if (sbi->read_bio) { > + submit_bio(rw, sbi->read_bio); > + sbi->read_bio = NULL; > + } > + up_read(&sbi->bio_sem); > +} > + > +void submit_read_page(struct f2fs_sb_info *sbi, struct page *page, > + block_t blk_addr, int rw) > +{ > + struct block_device *bdev = sbi->sb->s_bdev; > + int bio_blocks; > + > + verify_block_addr(sbi, blk_addr); > + > + down_read(&sbi->bio_sem); > + > + if (sbi->read_bio && sbi->last_read_block != blk_addr - 1) { > + submit_bio(rw, sbi->read_bio); > + sbi->read_bio = NULL; > + } > + > +alloc_new: > + if (sbi->read_bio == NULL) { > + bio_blocks = MAX_BIO_BLOCKS(max_hw_blocks(sbi)); > + sbi->read_bio = f2fs_bio_alloc(bdev, bio_blocks); > + sbi->read_bio->bi_sector = SECTOR_FROM_BLOCK(sbi, blk_addr); > + sbi->read_bio->bi_end_io = read_end_io; > + } > + > + if (bio_add_page(sbi->read_bio, page, PAGE_CACHE_SIZE, 0) < > + PAGE_CACHE_SIZE) { > + submit_bio(rw, sbi->read_bio); > + sbi->read_bio = NULL; > + goto alloc_new; > + } > + > + sbi->last_read_block = blk_addr; > + > + up_read(&sbi->bio_sem); > +} > + > /* > * This function should be used by the data read flow only where it > * does not check the "create" flag that indicates block allocation. > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > index 89dc750..0afdcec 100644 > --- a/fs/f2fs/f2fs.h > +++ b/fs/f2fs/f2fs.h > @@ -359,6 +359,8 @@ struct f2fs_sb_info { > > /* for segment-related operations */ > struct f2fs_sm_info *sm_info; /* segment manager */ > + struct bio *read_bio; /* read bios to merge */ > + sector_t last_read_block; /* last read block number */ > struct bio *bio[NR_PAGE_TYPE]; /* bios to merge */ > sector_t last_block_in_bio[NR_PAGE_TYPE]; /* last block number */ > struct rw_semaphore bio_sem; /* IO semaphore */