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 <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alex Belits <alex.belits@cavium.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: NeilBrown <neilb@suse.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Michal Hocko 2017-07-12 14:36:52 -07:00 коммит произвёл Linus Torvalds
Родитель 91c63ecda7
Коммит cc965a29db
1 изменённых файлов: 4 добавлений и 10 удалений

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@ -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;
}