On Tue, Oct 09, 2012 at 05:12:21AM +0200, Marek Szyprowski wrote: > Hello, > > On 10/9/2012 5:10 AM, Minchan Kim wrote: > > >On Mon, Oct 08, 2012 at 05:41:14PM +0200, Rabin Vincent wrote: > >>It appears that when CMA is enabled, the zone watermarks are not properly > >>respected, leading to for example GFP_NOWAIT allocations getting access to the > >>high pools. > >> > >>I ran the following test code which simply allocates pages with GFP_NOWAIT > >>until it fails, and then tries GFP_ATOMIC. Without CMA, the GFP_ATOMIC > >>allocation succeeds, with CMA, it fails too. > > > >Good spot. By wrong zone_watermark_check, it can consume reserved memory pool. > > That was the main reason for the Bartek's research. Okay. It shoud have written down for more good description at that time. :) > > >>Logs attached (includes my patch which prints the migration type in the failure > >>message http://marc.info/?l=linux-mm&m=134971041701306&w=2), taken on 3.6 > >>kernel. > >> > > > >Fortunately, recently, Bart sent a patch about that. > >http://marc.info/?l=linux-mm&m=134763299016693&w=2 > > > >Could you test above patches in your kernel? > >You have to apply [2/4], [3/4], [4/4] and don't need [1/4]. > > AFAIR without patch [1/4], free cma page counter will go below zero > and weird thing will happen, so better apply the complete patchset. I can't understand your point. [1/4] is just fix for correcting trace No? http://marc.info/?l=linux-mm&m=134763301216713&w=2 > > Best regards > -- > Marek Szyprowski > Samsung Poland R&D Center > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@xxxxxxxxx. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a> -- Kind regards, Minchan Kim -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>