dm cache: optimize dirty bit checking with find_next_bit when resizing
commit f484697e619a83ecc370443a34746379ad99d204 upstream.
When shrinking the fast device, dm-cache iteratively searches for a
dirty bit among the cache blocks to be dropped, which is less efficient.
Use find_next_bit instead, as it is twice as fast as the iterative
approach with test_bit.
BUG=None
TEST=None
RELEASE_NOTE=None
cos-patch: bug
Signed-off-by: Ming-Hung Tsai <mtsai@redhat.com>
Fixes: f494a9c6b1b6 ("dm cache: cache shrinking support")
Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Joe Thornber <thornber@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Change-Id: I6ed7f56f71750c27ed9490f279d955a0964bc971
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/88043
Reviewed-by: Anil Altinay <aaltinay@google.com>
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
1 file changed
