From 0d6526f82c3cdefcca47f73f5fc08dc6f335eac6 Mon Sep 17 00:00:00 2001 From: Tim Chen Date: Mon, 21 Sep 2026 17:37:22 -0700 Subject: sched/cache: Keep nr_pref_llc_running in the runnable domain, to fix LLC mis-scheduling bug 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 Suggested-by: Chen Yu Signed-off-by: Tim Chen Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Reviewed-by: Kayra Cizmeci Cc: # v7.2.x Link: https://patch.msgid.link/06af61afedac32e6477f57feb4d658f6c411c3af.1790035273.git.tim.c.chen@linux.intel.com --- net/wireless/Makefile | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) create mode 100644 net/wireless/Makefile (limited to 'net/wireless/Makefile') diff --git a/net/wireless/Makefile b/net/wireless/Makefile new file mode 100644 index 000000000..a77fd5ba6 --- /dev/null +++ b/net/wireless/Makefile @@ -0,0 +1,56 @@ +# SPDX-License-Identifier: GPL-2.0 +obj-$(CONFIG_CFG80211) += cfg80211.o +obj-y += tests/ + +obj-$(CONFIG_WEXT_CORE) += wext-core.o +obj-$(CONFIG_WEXT_PROC) += wext-proc.o +obj-$(CONFIG_WEXT_PRIV) += wext-priv.o + +cfg80211-y += core.o sysfs.o radiotap.o util.o reg.o scan.o nl80211.o +cfg80211-y += mlme.o ibss.o sme.o chan.o ethtool.o mesh.o ap.o trace.o ocb.o +cfg80211-y += michael-mic.o pmsr.o +cfg80211-$(CONFIG_OF) += of.o +cfg80211-$(CONFIG_CFG80211_DEBUGFS) += debugfs.o +cfg80211-$(CONFIG_CFG80211_WEXT) += wext-compat.o wext-sme.o + +CFLAGS_trace.o := -I$(src) + +cfg80211-$(CONFIG_CFG80211_USE_KERNEL_REGDB_KEYS) += shipped-certs.o +ifneq ($(CONFIG_CFG80211_EXTRA_REGDB_KEYDIR),) +cfg80211-y += extra-certs.o +endif + +$(obj)/shipped-certs.c: $(sort $(wildcard $(src)/certs/*.hex)) + @$(kecho) " GEN $@" + $(Q)(echo '#include "reg.h"'; \ + echo 'const u8 shipped_regdb_certs[] = {'; \ + echo | cat - $^ ; \ + echo '};'; \ + echo 'unsigned int shipped_regdb_certs_len = sizeof(shipped_regdb_certs);'; \ + ) > $@ + +$(obj)/extra-certs.c: $(CONFIG_CFG80211_EXTRA_REGDB_KEYDIR) \ + $(sort $(wildcard $(CONFIG_CFG80211_EXTRA_REGDB_KEYDIR)/*.x509)) + @$(kecho) " GEN $@" + $(Q)(set -e; \ + allf=""; \ + for f in $^ ; do \ + test -f $$f || continue;\ + # similar to hexdump -v -e '1/1 "0x%.2x," "\n"' \ + thisf=$$(od -An -v -tx1 < $$f | \ + sed -e 's/ /\n/g' | \ + sed -e 's/^[0-9a-f]\+$$/\0/;t;d' | \ + sed -e 's/^/0x/;s/$$/,/'); \ + # file should not be empty - maybe command substitution failed? \ + test ! -z "$$thisf";\ + allf=$$allf$$thisf;\ + done; \ + ( \ + echo '#include "reg.h"'; \ + echo 'const u8 extra_regdb_certs[] = {'; \ + echo "$$allf"; \ + echo '};'; \ + echo 'unsigned int extra_regdb_certs_len = sizeof(extra_regdb_certs);'; \ + ) > $@) + +clean-files += shipped-certs.c extra-certs.c -- cgit v1.3.1