From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <457D6944.4010703@yahoo.com.au> Date: Tue, 12 Dec 2006 01:20:52 +1100 From: Nick Piggin MIME-Version: 1.0 Subject: Re: Status of buffered write path (deadlock fixes) References: <45751712.80301@yahoo.com.au> <20061207195518.GG4497@ca-server1.us.oracle.com> <4578DBCA.30604@yahoo.com.au> <20061208234852.GI4497@ca-server1.us.oracle.com> <457D20AE.6040107@yahoo.com.au> In-Reply-To: <457D20AE.6040107@yahoo.com.au> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Mark Fasheh Cc: Linux Memory Management , linux-fsdevel@vger.kernel.org, linux-kernel , OGAWA Hirofumi , Andrew Morton List-ID: Nick Piggin wrote: > Mark Fasheh wrote: >> If we make the change I described above (looking for BH_New buffers >> outside >> the range passed), then zero length or partial shouldn't matter, but zero >> length instead of partial would be nicer imho just for the sake of >> reducing >> the total number of cases down to the entire range or zero length. > > > We don't want to do zero length, because we might make the theoretical > livelock much easier to hit (eg. in the case of many small iovecs). But > yes we can restrict ourselves to zero-length or full-length. On second thoughts, I think I'm wrong about that. Consider the last page of a file, which is uptodate. A full length commit, which extends the file, will expose transient zeroes if the usercopy fails. -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org