From cc965a29db172c28e25b9742db86a85766a08bf5 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Wed, 12 Jul 2017 14:36:52 -0700 Subject: [PATCH] mm: kvmalloc support __GFP_RETRY_MAYFAIL for all sizes Now that __GFP_RETRY_MAYFAIL has a reasonable semantic regardless of the request size we can drop the hackish implementation for !costly orders. __GFP_RETRY_MAYFAIL retries as long as the reclaim makes a forward progress and backs of when we are out of memory for the requested size. Therefore we do not need to enforce__GFP_NORETRY for !costly orders just to silent the oom killer anymore. Link: http://lkml.kernel.org/r/20170623085345.11304-5-mhocko@kernel.org Signed-off-by: Michal Hocko Acked-by: Vlastimil Babka Cc: Alex Belits Cc: Chris Wilson Cc: Christoph Hellwig Cc: Darrick J. Wong Cc: David Daney Cc: Johannes Weiner Cc: Mel Gorman Cc: NeilBrown Cc: Ralf Baechle Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/util.c | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-) diff --git a/mm/util.c b/mm/util.c index 6520f2d4a226..ee250e2cde34 100644 --- a/mm/util.c +++ b/mm/util.c @@ -339,9 +339,9 @@ EXPORT_SYMBOL(vm_mmap); * Uses kmalloc to get the memory but if the allocation fails then falls back * to the vmalloc allocator. Use kvfree for freeing the memory. * - * Reclaim modifiers - __GFP_NORETRY and __GFP_NOFAIL are not supported. __GFP_RETRY_MAYFAIL - * is supported only for large (>32kB) allocations, and it should be used only if - * kmalloc is preferable to the vmalloc fallback, due to visible performance drawbacks. + * Reclaim modifiers - __GFP_NORETRY and __GFP_NOFAIL are not supported. + * __GFP_RETRY_MAYFAIL is supported, and it should be used only if kmalloc is + * preferable to the vmalloc fallback, due to visible performance drawbacks. * * Any use of gfp flags outside of GFP_KERNEL should be consulted with mm people. */ @@ -366,13 +366,7 @@ void *kvmalloc_node(size_t size, gfp_t flags, int node) if (size > PAGE_SIZE) { kmalloc_flags |= __GFP_NOWARN; - /* - * We have to override __GFP_RETRY_MAYFAIL by __GFP_NORETRY for !costly - * requests because there is no other way to tell the allocator - * that we want to fail rather than retry endlessly. - */ - if (!(kmalloc_flags & __GFP_RETRY_MAYFAIL) || - (size <= PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) + if (!(kmalloc_flags & __GFP_RETRY_MAYFAIL)) kmalloc_flags |= __GFP_NORETRY; }