From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from haymarket.ed.ac.uk (haymarket.ed.ac.uk [129.215.128.53]) by kvack.org (8.8.7/8.8.7) with ESMTP id SAA30112 for ; Wed, 1 Jul 1998 18:14:52 -0400 Date: Wed, 1 Jul 1998 21:07:32 +0100 Message-Id: <199807012007.VAA04529@dax.dcs.ed.ac.uk> From: "Stephen C. Tweedie" MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Subject: Re: (reiserfs) Re: More on Re: (reiserfs) Reiserfs and ext2fs (was Re: (reiserfs) Sum Benchmarks (these look typical?)) In-Reply-To: References: <199806221138.MAA00852@dax.dcs.ed.ac.uk> <358F4FBE.821B333C@ricochet.net> <199806241154.MAA03544@dax.dcs.ed.ac.uk> <199806251100.MAA00835@dax.dcs.ed.ac.uk> <199806291035.LAA00733@dax.dcs.ed.ac.uk> <199806301610.RAA00957@dax.dcs.ed.ac.uk> <199807010912.KAA00789@dax.dcs.ed.ac.uk> Sender: owner-linux-mm@kvack.org To: "Eric W. Biederman" Cc: "Stephen C. Tweedie" , Hans Reiser , Shawn Leas , Reiserfs , Ken Tetrick , linux-mm@kvack.org List-ID: Hi, On 01 Jul 1998 08:11:46 -0500, ebiederm+eric@npwt.net (Eric W. Biederman) said: ST> Read the source code! We already do this. If one process or thread ST> msync()s a mapped file, its dirty pages get written to disk, ST> independently of any other processes on the same or other CPUs which ST> may still have the pages mapped and may still be writing to them. We ST> don't unmap pages for write; we just mark them non-dirty around all ST> ptes. > I just took the time and looked. > And in buffer.c in get_hash_table if we are returning a locked buffer, > we always wait on that buffer until it is unlocked. So to date we I > don't see us tempting fate, with writing to locked buffers. Whoops, yes, we do currently do copies for msync(). It's been too long since I was digging in that code... --Stephen