From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964993AbWDHBoc (ORCPT ); Fri, 7 Apr 2006 21:44:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964995AbWDHBoc (ORCPT ); Fri, 7 Apr 2006 21:44:32 -0400 Received: from smtp101.mail.mud.yahoo.com ([209.191.85.211]:12110 "HELO smtp101.mail.mud.yahoo.com") by vger.kernel.org with SMTP id S964993AbWDHBoc (ORCPT ); Fri, 7 Apr 2006 21:44:32 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com.au; h=Received:Message-ID:Date:From:User-Agent:X-Accept-Language:MIME-Version:To:CC:Subject:References:In-Reply-To:Content-Type:Content-Transfer-Encoding; b=VChrlzJI+dle83x4tYkh9sXGmsEeNx38WkICynPrm12tx/f7GhsAwJarnuxRLpyY1NUjRxojhwsf1aRyqa8zYKKyHWBxdoPk4fBfyd3DxWmD1lSekKkEFiz7FR8/KXX+TDrwuxW12VK2Sd5A2Ic1FezaUCmoFgsAU3lWLrOx+K4= ; Message-ID: <443710F7.3040201@yahoo.com.au> Date: Sat, 08 Apr 2006 11:25:11 +1000 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.12) Gecko/20051007 Debian/1.7.12-1 X-Accept-Language: en MIME-Version: 1.0 To: Con Kolivas CC: Andrew Morton , ck@vds.kolivas.org, linux list , linux-mm@kvack.org Subject: Re: [PATCH] mm: limit lowmem_reserve References: <200604021401.13331.kernel@kolivas.org> <200604081015.44771.kernel@kolivas.org> <443709F1.90906@yahoo.com.au> <200604081101.06066.kernel@kolivas.org> In-Reply-To: <200604081101.06066.kernel@kolivas.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Con Kolivas wrote: > On Saturday 08 April 2006 10:55, Nick Piggin wrote: > >>Con Kolivas wrote: >> >>>On Friday 07 April 2006 22:40, Nick Piggin wrote: >>> >>>>How would zone_watermark_ok always fail though? >>> >>>Withdrew this patch a while back; ignore >> >>Well, whether or not that particular patch isa good idea, it >>is definitely a bug if zone_watermark_ok could ever always >>fail due to lowmem reserve and we should fix it. > > > Ok. I think I presented enough information for why I thought zone_watermark_ok > would fail (for ZONE_DMA). With 16MB ZONE_DMA and a vmsplit of 3GB we have a > lowmem_reserve of 12MB. It's pretty hard to keep that much ZONE_DMA free, I > don't think I've ever seen that much free on my ZONE_DMA on an ordinary > desktop without any particular ZONE_DMA users. Changing the tunable can make > the lowmem_reserve larger than ZONE_DMA is on any vmsplit too as far as I > understand the ratio. > Umm, for ZONE_DMA allocations, ZONE_DMA isn't a lower zone. So that 12MB protection should never come into it (unless it is buggy?). -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com