From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH 02/16 v2] f2fs: add on-disk layout Date: Fri, 26 Oct 2012 08:18:17 +0000 Message-ID: <201210260818.18155.arnd@arndb.de> References: <001001cdb0c5$2ac96520$805c2f60$%kim@samsung.com> <1351077945.2097.9.camel@slavad-ubuntu> <00e601cdb32a$59fbe090$0df3a1b0$%kim@samsung.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: "'Vyacheslav Dubeyko'" , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org, viro@zeniv.linux.org.uk, tytso@mit.edu, chur.lee@samsung.com, cm224.lee@samsung.com, jooyoung.hwang@samsung.com To: Jaegeuk Kim Return-path: In-Reply-To: <00e601cdb32a$59fbe090$0df3a1b0$%kim@samsung.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Friday 26 October 2012, Jaegeuk Kim wrote: > > > + > > > +#define F2FS_ROOT_INO(sbi) (sbi->root_ino_num) > > > +#define F2FS_NODE_INO(sbi) (sbi->node_ino_num) > > > +#define F2FS_META_INO(sbi) (sbi->meta_ino_num) > > > + > > > +#define GFP_F2FS_MOVABLE (__GFP_WAIT | __GFP_IO | __GFP_ZERO) > > > + > > > +#define MAX_ACTIVE_LOGS 16 > > > +#define MAX_ACTIVE_NODE_LOGS 8 > > > +#define MAX_ACTIVE_DATA_LOGS 8 > > > > I think that it makes sense to comment the reasons of such limitations > > in MAX_ACTIVE_LOGS, MAX_ACTIVE_NODE_LOGS, MAX_ACTIVE_DATA_LOGS. > > The maximum number of logs is suggested by arnd before. > As I understood, why he suggested such a quite large number is for further > optimization of multiple logs without any on-disk layout changes. > And, I think it is quite enough. I agree. I think Vyacheslav was just asking you to add a comment explaining how we got to these numbers, like /* * The file format supports up to 16 active logs, which should be * more than enough for future optimizations. The implementation * currently uses no more than 6 logs. * Half the logs are used for nodes, the other half are used for data. */ Arnd