From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <40CFC67D.6020205@yahoo.com.au> Date: Wed, 16 Jun 2004 14:03:09 +1000 From: Nick Piggin MIME-Version: 1.0 Subject: Re: Keeping mmap'ed files in core regression in 2.6.7-rc References: <20040608142918.GA7311@traveler.cistron.net> <40CAA904.8080305@yahoo.com.au> <20040614140642.GE13422@traveler.cistron.net> <40CE66EE.8090903@yahoo.com.au> <20040615143159.GQ19271@traveler.cistron.net> <40CFBB75.1010702@yahoo.com.au> <20040615205017.15dd1f1d.akpm@osdl.org> In-Reply-To: <20040615205017.15dd1f1d.akpm@osdl.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: miquels@cistron.nl, linux-mm@kvack.org List-ID: Andrew Morton wrote: > Nick Piggin wrote: > >>Can you send the test app over? > > > logical next step. > > >>Andrew, do you have any ideas about how to fix this so far? > > > Not sure what, if anything, is wrong yet. It could be that reclaim is now > doing the "right" thing, but this particular workload preferred the "wrong" > thing. Needs more investigation. > > > >>>See how "cache" remains stable, but free/buffers memory is oscillating? >>>That shouldn't happen, right ? >>> >> >>If it is doing IO to large regions of mapped memory, the page reclaim >>can start getting a bit chunky. Not much you can do about it, but it >>shouldn't do any harm. > > > shrink_zone() will free arbitrarily large amounts of memory as the scanning > priority increases. Probably it shouldn't. > > Especially for kswapd, I think, because it can end up fighting with memory allocators and think it is getting into trouble. It should probably rather just keep putting along quietly. I have a few experimental patches that magnify this problem, so I'll be looking at fixing it soon. The tricky part will be trying to maintain a similar prev_priority / temp_priority balance. -- 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: aart@kvack.org