sched/cache: Keep nr_pref_llc_running in the runnable domain, to fix LLC mis-scheduling buggrafted

alb_break_llc() decides whether to break LLC preference during active
load balance. It does so by testing that every runnable fair task on the
source rq prefers its LLC:

	env->src_rq->nr_pref_llc_running == env->src_rq->cfs.h_nr_runnable

But the two counters cover different sets. nr_pref_llc_running is updated
in account_llc_enqueue()/account_llc_dequeue(), next to cfs_rq->nr_queued,
so it follows queued tasks. h_nr_runnable is updated in set_delayed()/
clear_delayed() and drops delay-dequeued tasks.

So under DELAY_DEQUEUE, a preferring task that goes to sleep stays counted
in nr_pref_llc_running while h_nr_runnable falls. The equality then breaks,
alb_break_llc() returns false, and active balance is free to pull a task
off its preferred LLC. Active balance only moves runnable tasks, and this
is the only LLC check it consults: once the stopper runs, LBF_ACTIVE_LB
skips the per-task test in can_migrate_task(). The runnable set is the one
we want.

Fix it on the counter side. A task should be counted in
nr_pref_llc_running exactly while it is both queued on its preferred LLC
(pref_llc_queued) and runnable (!sched_delayed). Define that membership
once in task_pref_llc_runnable(), and adjust the counter only through
pref_llc_running_inc()/pref_llc_running_dec() from the four sites that
change either input: account_llc_enqueue(), account_llc_dequeue(),
set_delayed() and clear_delayed(). Gating every update on the same
predicate keeps the delay, wake and dequeue paths from double-counting
or underflowing; see the comments at those sites for the ordering.

nr_llc_running and sd->llc_counts are not touched and stay on queued
semantics.

Fixes: 714059f79ff0 ("sched/cache: Handle moving single tasks to/from their preferred LLC")
Closes: https://lore.kernel.org/lkml/20260827135000.735138-1-zhanxusheng@xiaomi.com/
Reported-by: Zhan Xusheng <zhanxusheng@xiaomi.com>
Suggested-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Kayra Cizmeci <kayracizmeci@gmail.com>
Cc: <stable@kernel.org> # v7.2.x
Link: https://patch.msgid.link/06af61afedac32e6477f57feb4d658f6c411c3af.1790035273.git.tim.c.chen@linux.intel.com

1 files changed, 57 insertions, 0 deletions

diff --git a/drivers/crypto/aspeed/Kconfig b/drivers/crypto/aspeed/Kconfig
new file mode 100644
index 000000000..e93f2f82b
--- /dev/null
+++ b/drivers/crypto/aspeed/Kconfig
@@ -0,0 +1,57 @@
+config CRYPTO_DEV_ASPEED
+	tristate "Support for Aspeed cryptographic engine driver"
+	depends on ARCH_ASPEED || COMPILE_TEST
+	select CRYPTO_ENGINE
+	help
+	  Hash and Crypto Engine (HACE) is designed to accelerate the
+	  throughput of hash data digest, encryption and decryption.
+
+	  Select y here to have support for the cryptographic driver
+	  available on Aspeed SoC.
+
+config CRYPTO_DEV_ASPEED_DEBUG
+	bool "Enable Aspeed crypto debug messages"
+	depends on CRYPTO_DEV_ASPEED
+	help
+	  Print Aspeed crypto debugging messages if you use this
+	  option to ask for those messages.
+	  Avoid enabling this option for production build to
+	  minimize driver timing.
+
+config CRYPTO_DEV_ASPEED_HACE_HASH
+	bool "Enable Aspeed Hash & Crypto Engine (HACE) hash"
+	depends on CRYPTO_DEV_ASPEED
+	select CRYPTO_SHA1
+	select CRYPTO_SHA256
+	select CRYPTO_SHA512
+	select CRYPTO_HMAC
+	help
+	  Select here to enable Aspeed Hash & Crypto Engine (HACE)
+	  hash driver.
+	  Supports multiple message digest standards, including
+	  SHA-1, SHA-224, SHA-256, SHA-384, SHA-512, and so on.
+
+config CRYPTO_DEV_ASPEED_HACE_CRYPTO
+	bool "Enable Aspeed Hash & Crypto Engine (HACE) crypto"
+	depends on CRYPTO_DEV_ASPEED
+	select CRYPTO_AES
+	select CRYPTO_DES
+	select CRYPTO_ECB
+	select CRYPTO_CBC
+	select CRYPTO_CTR
+	help
+	  Select here to enable Aspeed Hash & Crypto Engine (HACE)
+	  crypto driver.
+	  Supports AES/DES symmetric-key encryption and decryption
+	  with ECB/CBC/CTR options.
+
+config CRYPTO_DEV_ASPEED_ACRY
+	bool "Enable Aspeed ACRY RSA Engine"
+	depends on CRYPTO_DEV_ASPEED
+	select CRYPTO_ENGINE
+	select CRYPTO_RSA
+	help
+	  Select here to enable Aspeed ECC/RSA Engine (ACRY)
+	  RSA driver.
+	  Supports 256 bits to 4096 bits RSA encryption/decryption
+	  and signature/verification.