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, 61 insertions, 0 deletions

diff --git a/sound/soc/sof/Makefile b/sound/soc/sof/Makefile
new file mode 100644
index 000000000..b0b22e6eb
--- /dev/null
+++ b/sound/soc/sof/Makefile
@@ -0,0 +1,61 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause)
+
+snd-sof-y := core.o ops.o loader.o ipc.o pcm.o pm.o debug.o topology.o\
+		control.o trace.o iomem-utils.o sof-audio.o stream-ipc.o\
+		fw-file-profile.o
+
+# IPC implementations
+ifneq ($(CONFIG_SND_SOC_SOF_IPC3),)
+snd-sof-y +=	ipc3.o ipc3-loader.o ipc3-topology.o ipc3-control.o ipc3-pcm.o\
+		ipc3-dtrace.o
+endif
+ifneq ($(CONFIG_SND_SOC_SOF_IPC4),)
+snd-sof-y += ipc4.o ipc4-loader.o ipc4-topology.o ipc4-control.o ipc4-pcm.o\
+		ipc4-mtrace.o ipc4-telemetry.o
+endif
+
+# SOF client support
+ifneq ($(CONFIG_SND_SOC_SOF_CLIENT),)
+snd-sof-y += sof-client.o
+endif
+
+snd-sof-$(CONFIG_SND_SOC_SOF_COMPRESS) += compress.o
+
+snd-sof-pci-y := sof-pci-dev.o
+snd-sof-acpi-y := sof-acpi-dev.o
+snd-sof-of-y := sof-of-dev.o
+
+snd-sof-ipc-flood-test-y := sof-client-ipc-flood-test.o
+snd-sof-ipc-msg-injector-y := sof-client-ipc-msg-injector.o
+snd-sof-ipc-kernel-injector-y := sof-client-ipc-kernel-injector.o
+snd-sof-probes-y := sof-client-probes.o
+ifneq ($(CONFIG_SND_SOC_SOF_IPC3),)
+snd-sof-probes-y += sof-client-probes-ipc3.o
+endif
+ifneq ($(CONFIG_SND_SOC_SOF_IPC4),)
+snd-sof-probes-y += sof-client-probes-ipc4.o
+endif
+
+snd-sof-nocodec-y := nocodec.o
+
+snd-sof-utils-y := sof-utils.o
+
+obj-$(CONFIG_SND_SOC_SOF) += snd-sof.o
+obj-$(CONFIG_SND_SOC_SOF_NOCODEC) += snd-sof-nocodec.o
+
+obj-$(CONFIG_SND_SOC_SOF) += snd-sof-utils.o
+
+obj-$(CONFIG_SND_SOC_SOF_ACPI_DEV) += snd-sof-acpi.o
+obj-$(CONFIG_SND_SOC_SOF_OF_DEV) += snd-sof-of.o
+obj-$(CONFIG_SND_SOC_SOF_PCI_DEV) += snd-sof-pci.o
+
+obj-$(CONFIG_SND_SOC_SOF_DEBUG_IPC_FLOOD_TEST) += snd-sof-ipc-flood-test.o
+obj-$(CONFIG_SND_SOC_SOF_DEBUG_IPC_MSG_INJECTOR) += snd-sof-ipc-msg-injector.o
+obj-$(CONFIG_SND_SOC_SOF_DEBUG_IPC_KERNEL_INJECTOR) += snd-sof-ipc-kernel-injector.o
+obj-$(CONFIG_SND_SOC_SOF_DEBUG_PROBES) += snd-sof-probes.o
+
+obj-$(CONFIG_SND_SOC_SOF_INTEL_TOPLEVEL) += intel/
+obj-$(CONFIG_SND_SOC_SOF_IMX_TOPLEVEL) += imx/
+obj-$(CONFIG_SND_SOC_SOF_AMD_TOPLEVEL) += amd/
+obj-$(CONFIG_SND_SOC_SOF_XTENSA) += xtensa/
+obj-$(CONFIG_SND_SOC_SOF_MTK_TOPLEVEL) += mediatek/