On Fri, 28 Sep 2007 20:25:50 +0200 Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> wrote: > > On Fri, 2007-09-28 at 11:20 -0700, Christoph Lameter wrote: > > > > start 2 processes that each mmap a separate 64M file, and which does > > > sequential writes on them. start a 3th process that does the same with > > > 64M anonymous. > > > > > > wait for a while, and you'll see order=1 failures. > > > > Really? That means we can no longer even allocate stacks for forking. > > > > Its surprising that neither lumpy reclaim nor the mobility patches can > > deal with it? Lumpy reclaim should be able to free neighboring pages to > > avoid the order 1 failure unless there are lots of pinned pages. > > > > I guess then that lots of pages are pinned through I/O? > > memory got massively fragemented, as anti-frag gets easily defeated. > setting min_free_kbytes to 12M does seem to solve it - it forces 2 max > order blocks to stay available, so we don't mix types. however 12M on > 128M is rather a lot. > > its still on my todo list to look at it further.. > That would be really really bad (as in: patch-dropping time) if those order-1 allocations are not atomic. What's the callsite? - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
