From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by ug-out-1314.google.com with SMTP id s2so2107052uge for ; Fri, 01 Dec 2006 02:00:53 -0800 (PST) Message-ID: <6d6a94c50612010200t2c9dfc36m603ddc4948285bf@mail.gmail.com> Date: Fri, 1 Dec 2006 18:00:53 +0800 From: Aubrey Subject: Re: The VFS cache is not freed when there is not enough free memory to allocate In-Reply-To: <456F4A95.2090503@yahoo.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <6d6a94c50611212351if1701ecx7b89b3fe79371554@mail.gmail.com> <1164185036.5968.179.camel@twins> <6d6a94c50611220202t1d076b4cye70dcdcc19f56e55@mail.gmail.com> <456A964D.2050004@yahoo.com.au> <4e5ebad50611282317r55c22228qa5333306ccfff28e@mail.gmail.com> <6d6a94c50611290127u2b26976en1100217a69d651c0@mail.gmail.com> <456D5347.3000208@yahoo.com.au> <6d6a94c50611300454g22196d2frec54e701abaebf17@mail.gmail.com> <456F4A95.2090503@yahoo.com.au> Sender: owner-linux-mm@kvack.org Return-Path: To: Nick Piggin Cc: Sonic Zhang , Peter Zijlstra , linux-kernel@vger.kernel.org, linux-mm@kvack.org, vapier.adi@gmail.com List-ID: On 12/1/06, Nick Piggin wrote: > > The pattern you are seeing here is probably due to the page allocator > always retrying process context allocations which are <= order 3 (64K > with 4K pages). > > You might be able to increase this limit a bit for your system, but it > could easily cause problems. Especially fragmentation on nommu systems > where the anonymous memory cannot be paged out. Thanks for your clue. I found increasing this limit could really help my test cases. When MemFree < 8M, and the test case request 1M * 8 times, the allocation can be sucessful after 81 times rebalance, :). So far I haven't found any issue. If I make a patch to move this parameter to be tunable in the proc filesystem on nommu case, is it acceptable? Thanks, -Aubrey -- 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