bcache: remove unnecessary select MIN_HEAP

commit 95b2e31e1752494d477c5da89d6789f769b0d67b upstream.

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+pCRyWTKLEOsc8BOmH73p1m+KQ@mail.gmail.com
Link: https://lkml.kernel.org/r/20250614202353.1632957-4-visitorckw@gmail.com
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")
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Reported-by: Robert Pang <robertpang@google.com>
Closes: https://lore.kernel.org/linux-bcache/CAJhEC06F_AtrPgw2-7CvCqZgeStgCtitbD-ryuPpXQA-JG5XXw@mail.gmail.com
Acked-by: Coly Li <colyli@kernel.org>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/md/bcache/Kconfig b/drivers/md/bcache/Kconfig
index d4697e79d5a391a8f3effc7e72e1c0c9998e4ce0..b2d10063d35fb48ddb542f6934aa7ad172d276f1 100644 (file)
--- 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.