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Michal Hocko authored
Gao Xiang has reported that the page allocator complains about high order __GFP_NOFAIL request coming from the vmalloc core: __alloc_pages+0x1cb/0x5b0 mm/page_alloc.c:5549 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2286 vm_area_alloc_pages mm/vmalloc.c:2989 [inline] __vmalloc_area_node mm/vmalloc.c:3057 [inline] __vmalloc_node_range+0x978/0x13c0 mm/vmalloc.c:3227 kvmalloc_node+0x156/0x1a0 mm/util.c:606 kvmalloc include/linux/slab.h:737 [inline] kvmalloc_array include/linux/slab.h:755 [inline] kvcalloc include/linux/slab.h:760 [inline] it seems that I have completely missed high order allocation backing vmalloc areas case when implementing __GFP_NOFAIL support. This means that [k]vmalloc at al. can allocate higher order allocations with __GFP_NOFAIL which can trigger OOM killer for non-costly orders easily or cause a lot of reclaim/compaction activity if those requests cannot be satisfied. Fix the issue by falling back to zero order allocations for __GFP_NOFAIL requests if the high order request fails. Link: https://lkml.kernel.org/r/ZAXynvdNqcI0f6Us@dhcp22.suse.cz Fixes: 9376130c ("mm/vmalloc: add support for __GFP_NOFAIL") Reported-by: Gao Xiang <hsiangkao@linux.alibaba.com> Link: https://lkml.kernel.org/r/20230305053035.1911-1-hsiangkao@linux.alibaba.comSigned-off-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Baoquan He <bhe@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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