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linux/drivers/md/dm-cache-background-tracker.c

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dm cache: significant rework to leverage dm-bio-prison-v2 The cache policy interfaces have been updated to work well with the new bio-prison v2 interface's ability to queue work immediately (promotion, demotion, etc) -- overriding benefit being reduced latency on processing IO through the cache. Previously such work would be left for the DM cache core to queue on various lists and then process in batches later -- this caused a serious delay in latency for IO driven by the cache. The background tracker code was factored out so that all cache policies can make use of it. Also, the "cleaner" policy has been removed and is now a variant of the smq policy that simply disallows migrations. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-12-15 04:57:31 -05:00
dm cache: handle kmalloc failure allocating background_tracker struct Currently there is no kmalloc failure check on the allocation of the background_tracker struct in btracker_create(), and so a NULL return will lead to a NULL pointer dereference. Add a NULL check. Detected by CoverityScan, CID#1416587 ("Dereference null return value") Fixes: b29d4986d ("dm cache: significant rework to leverage dm-bio-prison-v2") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-03-11 19:09:45 +00:00
dm cache: significant rework to leverage dm-bio-prison-v2 The cache policy interfaces have been updated to work well with the new bio-prison v2 interface's ability to queue work immediately (promotion, demotion, etc) -- overriding benefit being reduced latency on processing IO through the cache. Previously such work would be left for the DM cache core to queue on various lists and then process in batches later -- this caused a serious delay in latency for IO driven by the cache. The background tracker code was factored out so that all cache policies can make use of it. Also, the "cleaner" policy has been removed and is now a variant of the smq policy that simply disallows migrations. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-12-15 04:57:31 -05:00