After reverting the transition to the generic min heap library, bcache no longer depends on MIN_HEAP. The select entry can be removed to reduce code size and shrink the kernel's attack surface.
This change effectively reverts the bcache-related part of commit 92a8b224b833 ("lib/min_heap: introduce non-inline versions of min heap API functions").
This is part of a series of changes to address a performance regression caused by the use of the generic min_heap implementation.
As reported by Robert, bcache now suffers from latency spikes, with P100 (max) latency increasing from 600 ms to 2.4 seconds every 5 minutes. These regressions degrade bcache's effectiveness as a low-latency cache layer and lead to frequent timeouts and application stalls in production environments.
Link: https://lore.kernel.org/lkml/CAJhEC05+0S69z+3+FB2Cd0hD+pCRyWTKLEOsc8BOmH73p1... Fixes: 866898efbb25 ("bcache: remove heap-related macros and switch to generic min_heap") Fixes: 92a8b224b833 ("lib/min_heap: introduce non-inline versions of min heap API functions") Reported-by: Robert Pang robertpang@google.com Closes: https://lore.kernel.org/linux-bcache/CAJhEC06F_AtrPgw2-7CvCqZgeStgCtitbD-ryu... Cc: stable@vger.kernel.org Signed-off-by: Kuan-Wei Chiu visitorckw@gmail.com --- drivers/md/bcache/Kconfig | 1 - 1 file changed, 1 deletion(-)
diff --git a/drivers/md/bcache/Kconfig b/drivers/md/bcache/Kconfig index d4697e79d5a3..b2d10063d35f 100644 --- a/drivers/md/bcache/Kconfig +++ b/drivers/md/bcache/Kconfig @@ -5,7 +5,6 @@ config BCACHE select BLOCK_HOLDER_DEPRECATED if SYSFS select CRC64 select CLOSURES - select MIN_HEAP help Allows a block device to be used as cache for other devices; uses a btree for indexing and the layout is optimized for SSDs.
On Sun, Jun 15, 2025 at 04:23:53AM +0800, Kuan-Wei Chiu wrote:
After reverting the transition to the generic min heap library, bcache no longer depends on MIN_HEAP. The select entry can be removed to reduce code size and shrink the kernel's attack surface.
This change effectively reverts the bcache-related part of commit 92a8b224b833 ("lib/min_heap: introduce non-inline versions of min heap API functions").
This is part of a series of changes to address a performance regression caused by the use of the generic min_heap implementation.
As reported by Robert, bcache now suffers from latency spikes, with P100 (max) latency increasing from 600 ms to 2.4 seconds every 5 minutes. These regressions degrade bcache's effectiveness as a low-latency cache layer and lead to frequent timeouts and application stalls in production environments.
Link: https://lore.kernel.org/lkml/CAJhEC05+0S69z+3+FB2Cd0hD+pCRyWTKLEOsc8BOmH73p1... Fixes: 866898efbb25 ("bcache: remove heap-related macros and switch to generic min_heap") Fixes: 92a8b224b833 ("lib/min_heap: introduce non-inline versions of min heap API functions") Reported-by: Robert Pang robertpang@google.com Closes: https://lore.kernel.org/linux-bcache/CAJhEC06F_AtrPgw2-7CvCqZgeStgCtitbD-ryu... Cc: stable@vger.kernel.org Signed-off-by: Kuan-Wei Chiu visitorckw@gmail.com
Acked-by: Coly Li colyli@kernel.org
Thanks.
drivers/md/bcache/Kconfig | 1 - 1 file changed, 1 deletion(-)
diff --git a/drivers/md/bcache/Kconfig b/drivers/md/bcache/Kconfig index d4697e79d5a3..b2d10063d35f 100644 --- a/drivers/md/bcache/Kconfig +++ b/drivers/md/bcache/Kconfig @@ -5,7 +5,6 @@ config BCACHE select BLOCK_HOLDER_DEPRECATED if SYSFS select CRC64 select CLOSURES
- select MIN_HEAP help Allows a block device to be used as cache for other devices; uses a btree for indexing and the layout is optimized for SSDs.
-- 2.34.1
linux-stable-mirror@lists.linaro.org
-
Coly Li -
Kuan-Wei Chiu