On Tue, Apr 26, 2011 at 2:25 PM, Wu Fengguang <fengguang.wu@xxxxxxxxx> wrote: > On Tue, Apr 26, 2011 at 02:07:17PM +0800, Dave Young wrote: >> On Tue, Apr 26, 2011 at 2:05 PM, Dave Young <hidave.darkstar@xxxxxxxxx> wrote: >> > On Tue, Apr 26, 2011 at 1:55 PM, Wu Fengguang <fengguang.wu@xxxxxxxxx> wrote: >> >> On Tue, Apr 26, 2011 at 01:49:25PM +0800, Dave Young wrote: >> >>> Hi, >> >>> >> >>> When memory pressure is high, readahead could cause oom killing. >> >>> IMHO we should stop readaheading under such circumstancesãIf it's true >> >>> how to fix it? >> >> >> >> Good question. Before OOM there will be readahead thrashings, which >> >> can be addressed by this patch: >> >> >> >> http://lkml.org/lkml/2010/2/2/229 >> > >> > Hi, I'm not clear about the patch, could be regard as below cases? >> > 1) readahead alloc fail due to low memory such as other large allocation >> >> For example vm balloon allocate lots of memory, then readahead could >> fail immediately and then oom > > If true, that would be the problem of vm balloon. It's not good to > consume lots of memory all of a sudden, which will likely impact lots > of kernel subsystems. > > btw readahead page allocations are completely optional. They are OK to > fail and in theory shall not trigger OOM on themselves. We may > consider passing __GFP_NORETRY for readahead page allocations. Good idea, care to submit a patch? -- Regards dave -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href