Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752944AbbHTRRk (ORCPT ); Thu, 20 Aug 2015 13:17:40 -0400 Received: from mail.kernel.org ([198.145.29.136]:51048 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752601AbbHTRRV (ORCPT ); Thu, 20 Aug 2015 13:17:21 -0400 Date: Thu, 20 Aug 2015 10:17:18 -0700 From: Jaegeuk Kim To: Chao Yu Cc: linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/9] f2fs: avoid unneeded initializing when converting inline dentry Message-ID: <20150820171718.GC42028@jaegeuk-mac02.mot-mobility.com> References: <017601d0da6f$bcb555d0$36200170$@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <017601d0da6f$bcb555d0$36200170$@samsung.com> 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 Content-Length: 2440 Lines: 64 Hi Chao, On Wed, Aug 19, 2015 at 07:10:19PM +0800, Chao Yu wrote: > When converting inline dentry, we will zero out target dentry page before > duplicating data of inline dentry into target page, it become overhead > since inline dentry size is not small. > > So this patch tries to remove unneeded initializing in the space of target > dentry page. > > Signed-off-by: Chao Yu > --- > fs/f2fs/inline.c | 15 ++++++++++++++- > 1 file changed, 14 insertions(+), 1 deletion(-) > > diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c > index 79d18d5..e4da0d7 100644 > --- a/fs/f2fs/inline.c > +++ b/fs/f2fs/inline.c > @@ -384,17 +384,30 @@ static int f2fs_convert_inline_dir(struct inode *dir, struct page *ipage, > goto out; > > f2fs_wait_on_page_writeback(page, DATA); > - zero_user_segment(page, 0, PAGE_CACHE_SIZE); > + zero_user_segment(page, MAX_INLINE_DATA, PAGE_CACHE_SIZE); > > dentry_blk = kmap_atomic(page); > > /* copy data from inline dentry block to new dentry block */ > memcpy(dentry_blk->dentry_bitmap, inline_dentry->dentry_bitmap, > INLINE_DENTRY_BITMAP_SIZE); > + memset(dentry_blk->dentry_bitmap + INLINE_DENTRY_BITMAP_SIZE, 0, > + SIZE_OF_DENTRY_BITMAP - INLINE_DENTRY_BITMAP_SIZE); Setting zeros for bitmap would be enough. It doesn't need to copy or set zeros for reserved, dentries, and filename slots. Thanks, > + /* > + * reserved space size of inline dentry is larger than the one of > + * regular dentry, here we just copy with the size of reserved space > + * in regular dentry. > + */ > + memcpy(dentry_blk->reserved, inline_dentry->reserved, SIZE_OF_RESERVED); > memcpy(dentry_blk->dentry, inline_dentry->dentry, > sizeof(struct f2fs_dir_entry) * NR_INLINE_DENTRY); > + memset(dentry_blk->dentry + NR_INLINE_DENTRY, 0, > + sizeof (struct f2fs_dir_entry) * > + (NR_DENTRY_IN_BLOCK - NR_INLINE_DENTRY)); > memcpy(dentry_blk->filename, inline_dentry->filename, > NR_INLINE_DENTRY * F2FS_SLOT_LEN); > + memset(&dentry_blk->filename[NR_INLINE_DENTRY][0], 0, > + F2FS_SLOT_LEN * (NR_DENTRY_IN_BLOCK - NR_INLINE_DENTRY)); > > kunmap_atomic(dentry_blk); > SetPageUptodate(page); > -- > 2.4.2 -- 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/