This is a note to let you know that I've just added the patch titled rbd: use GFP_NOIO consistently for request allocations to the 4.5-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: rbd-use-gfp_noio-consistently-for-request-allocations.patch and it can be found in the queue-4.5 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 2224d879c7c0f85c14183ef82eb48bd875ceb599 Mon Sep 17 00:00:00 2001 From: David Disseldorp <ddiss@xxxxxxx> Date: Tue, 5 Apr 2016 11:13:39 +0200 Subject: rbd: use GFP_NOIO consistently for request allocations From: David Disseldorp <ddiss@xxxxxxx> commit 2224d879c7c0f85c14183ef82eb48bd875ceb599 upstream. As of 5a60e87603c4c533492c515b7f62578189b03c9c, RBD object request allocations are made via rbd_obj_request_create() with GFP_NOIO. However, subsequent OSD request allocations in rbd_osd_req_create*() use GFP_ATOMIC. With heavy page cache usage (e.g. OSDs running on same host as krbd client), rbd_osd_req_create() order-1 GFP_ATOMIC allocations have been observed to fail, where direct reclaim would have allowed GFP_NOIO allocations to succeed. Suggested-by: Vlastimil Babka <vbabka@xxxxxxx> Suggested-by: Neil Brown <neilb@xxxxxxxx> Signed-off-by: David Disseldorp <ddiss@xxxxxxx> Signed-off-by: Ilya Dryomov <idryomov@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/block/rbd.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -1955,7 +1955,7 @@ static struct ceph_osd_request *rbd_osd_ osdc = &rbd_dev->rbd_client->client->osdc; osd_req = ceph_osdc_alloc_request(osdc, snapc, num_ops, false, - GFP_ATOMIC); + GFP_NOIO); if (!osd_req) return NULL; /* ENOMEM */ @@ -2004,7 +2004,7 @@ rbd_osd_req_create_copyup(struct rbd_obj rbd_dev = img_request->rbd_dev; osdc = &rbd_dev->rbd_client->client->osdc; osd_req = ceph_osdc_alloc_request(osdc, snapc, num_osd_ops, - false, GFP_ATOMIC); + false, GFP_NOIO); if (!osd_req) return NULL; /* ENOMEM */ @@ -2506,7 +2506,7 @@ static int rbd_img_request_fill(struct r bio_chain_clone_range(&bio_list, &bio_offset, clone_size, - GFP_ATOMIC); + GFP_NOIO); if (!obj_request->bio_list) goto out_unwind; } else if (type == OBJ_REQUEST_PAGES) { Patches currently in stable-queue which might be from ddiss@xxxxxxx are queue-4.5/rbd-use-gfp_noio-consistently-for-request-allocations.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html