On Fri, Apr 18, 2014 at 12:14:16PM -0700, Andrew Morton wrote: > On Thu, 10 Apr 2014 08:05:06 +0100 Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> wrote: > > > During testing of i915.ko with working texture sets larger than RAM, we > > encounter OOM with plenty of memory still trapped within writeback, e.g: > > > > [ 42.386039] active_anon:10134 inactive_anon:1900781 isolated_anon:32 > > active_file:33 inactive_file:39 isolated_file:0 > > unevictable:0 dirty:0 writeback:337627 unstable:0 > > free:11985 slab_reclaimable:9458 slab_unreclaimable:23614 > > mapped:41 shmem:1560769 pagetables:1276 bounce:0 > > > > If we throttle for writeback following shrink_slab, this gives us time > > to wait upon the writeback generated by the i915.ko shinker: > > > > [ 4756.750808] active_anon:24386 inactive_anon:900793 isolated_anon:0 > > active_file:23 inactive_file:20 isolated_file:0 > > unevictable:0 dirty:0 writeback:0 unstable:0 > > free:5550 slab_reclaimable:5184 slab_unreclaimable:4888 > > mapped:3 shmem:472393 pagetables:1249 bounce:0 > > > > (Sadly though the test is still failing.) > > > > Testcase: igt/gem_tiled_swapping > > References: https://bugs.freedesktop.org/show_bug.cgi?id=72742 > > i915_gem_object_get_pages_gtt() makes my head spin, but > https://bugs.freedesktop.org/attachment.cgi?id=90818 says > "gfp_mask=0x201da" which is > > ___GFP_HARDWALL|___GFP_COLD|___GFP_FS|___GFP_IO|___GFP_WAIT|___GFP_MOVABLE|___GFP_HIGHMEM > > so this allocation should work and it very bad if the page allocator is > declaring oom while there is so much writeback in flight, assuming the > writeback is to eligible zones. For more head spinning look at the lock stealing dance we do in our shrinker callbacks i915_gem_inactive_scan|count(). It's not pretty at all, but it helps to avoids the dreaded oom in a few more cases. Some review of our mess of ducttape from -mm developers with actual clue would be really appreciated ... -Daniel > Mel, Johannes: could you take a look please? > > -- > 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> -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch -- 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>