From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <443710F7.3040201@yahoo.com.au> Date: Sat, 08 Apr 2006 11:25:11 +1000 From: Nick Piggin MIME-Version: 1.0 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: owner-linux-mm@kvack.org Return-Path: To: Con Kolivas Cc: Andrew Morton , ck@vds.kolivas.org, linux list , linux-mm@kvack.org List-ID: 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 -- 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