On Fri, Sep 25, 2015 at 05:47:12PM +0800, Chao Yu wrote: > Hi Marc Jaegeuk, > > > -----Original Message----- > > From: Marc Lehmann [mailto:schm...@schmorp.de] > > Sent: Friday, September 25, 2015 2:51 PM > > To: Jaegeuk Kim > > Cc: linux-f2fs-devel@lists.sourceforge.net > > Subject: Re: [f2fs-dev] write performance difference 3.18.21/4.2.1 > > > > On Thu, Sep 24, 2015 at 11:28:36AM -0700, Jaegeuk Kim <jaeg...@kernel.org> > > wrote: > > > One thing that we can try is to run the latest f2fs source in v3.18. > > > This branch supports f2fs for v3.18. > > > > Ok, please bear with me, the last time I built my own kernel was during > > the 2.4 timeframe, and this is a ubuntu kernel. What I did is this: > > > > git clone -b linux-3.18 > > git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs.git > > cd f2fs/fs/f2fs > > rsync -avPR include/linux/f2fs_fs.h include/trace/events/f2fs.h > > /usr/src/linux-headers-3.18.21-031821/. > > make -C /lib/modules/3.18.21-031821-generic/build/ M=$PWD modules > > modules_install > > > > I then rmmod f2fs/insmod the resulting module, and tried to mount my > > existing f2fs fs for a quick test, but got a null ptr exception on "mount": > > > > http://ue.tst.eu/e4628dcee97324e580da1bafad938052.txt > > This is my fault, sorry about introducing this oops. :( > > Please revert the commit 7c5e466755ff ("f2fs: readahead cp payload > pages when mount") since in this commit we try to access invalid > SIT_I(sbi)->sit_base_addr which should be inited later.
Oops, I'll just remove this patch which was not going too far away. Thanks, > > Thanks, > > > > > Probably caused me not building a full kernel, but recreating how ubuntu > > build their kernels on a debian system isn't something I look forward to. > > > > > For example, if I can represent blocks like: > > [number of logs discussion] > > > > Thanks for this explanation - two logs doesn't look so bad, from a > > locality viewpoint (not a big issue for flash, but a big issue for > > rotational devices - I also realised I can't use dmcache as dmcache, even > > in writethrough mode, writes back all data after an unclean shutdown, > > which would positively kill the disk). > > > > Since whatever speed difference I saw with two logs wasn't big, you > > completely sold me on 6 logs, or 4 (especially if it seepds up the gc, > > which I haven't much tested yet). Two logs was merely a test anyway (the > > same with no_heap, I don't know what it does, but I thought it is worth > > a try, as metadata + data nearer together is better than having them at > > opposite ends of the log or so). > > > > -- > > The choice of a Deliantra, the free code+content MORPG > > -----==- _GNU_ http://www.deliantra.net > > ----==-- _ generation > > ---==---(_)__ __ ____ __ Marc Lehmann > > --==---/ / _ \/ // /\ \/ / schm...@schmorp.de > > -=====/_/_//_/\_,_/ /_/\_\ > > > > ------------------------------------------------------------------------------ > > _______________________________________________ > > Linux-f2fs-devel mailing list > > Linux-f2fs-devel@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel ------------------------------------------------------------------------------ _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
