mm: io_uring: allow oom-killer from io_uring_setup

[ Upstream commit 0a3f1e0beacf6cc8ae5f846b0641c1df476e83d6 ]

On an overcommitted system which is running multiple workloads of
varying priorities, it is preferred to trigger an oom-killer to kill a
low priority workload than to let the high priority workload receiving
ENOMEMs. On our memory overcommitted systems, we are seeing a lot of
ENOMEMs instead of oom-kills because io_uring_setup callchain is using
__GFP_NORETRY gfp flag which avoids the oom-killer. Let's remove it and
allow the oom-killer to kill a lower priority job.

Signed-off-by: Shakeel Butt <shakeelb@google.com>
Link: https://lore.kernel.org/r/20220125051736.2981459-1-shakeelb@google.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 993913c..21fc8ce 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -8820,10 +8820,9 @@ static void io_mem_free(void *ptr)
 
 static void *io_mem_alloc(size_t size)
 {
-       gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN | __GFP_COMP |
-                               __GFP_NORETRY | __GFP_ACCOUNT;
+       gfp_t gfp = GFP_KERNEL_ACCOUNT | __GFP_ZERO | __GFP_NOWARN | __GFP_COMP;
 
-       return (void *) __get_free_pages(gfp_flags, get_order(size));
+       return (void *) __get_free_pages(gfp, get_order(size));
 }
 
 static unsigned long rings_size(unsigned sq_entries, unsigned cq_entries,