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, 138 insertions, 0 deletions

diff --git a/drivers/media/dvb-frontends/Makefile b/drivers/media/dvb-frontends/Makefile
new file mode 100644
index 000000000..a93146cb4
--- /dev/null
+++ b/drivers/media/dvb-frontends/Makefile
@@ -0,0 +1,138 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the kernel DVB frontend device drivers.
+#
+
+ccflags-y += -I$(srctree)/drivers/media/tuners/
+
+# FIXME: RTL2832 SDR driver uses power management directly from USB IF driver
+ifdef CONFIG_DVB_RTL2832_SDR
+	ccflags-y += -I$(srctree)/drivers/media/usb/dvb-usb-v2
+endif
+
+cxd2820r-objs := cxd2820r_core.o cxd2820r_c.o cxd2820r_t.o cxd2820r_t2.o
+drxd-objs := drxd_firm.o drxd_hard.o
+drxk-objs := drxk_hard.o
+stb0899-objs := stb0899_drv.o stb0899_algo.o
+stv0900-objs := stv0900_core.o stv0900_sw.o
+
+# Please keep it alphabetically sorted by Kconfig name
+# (e. g. LC_ALL=C sort Makefile)
+
+obj-$(CONFIG_DVB_A8293) += a8293.o
+obj-$(CONFIG_DVB_AF9013) += af9013.o
+obj-$(CONFIG_DVB_AF9033) += af9033.o
+obj-$(CONFIG_DVB_AS102_FE) += as102_fe.o
+obj-$(CONFIG_DVB_ASCOT2E) += ascot2e.o
+obj-$(CONFIG_DVB_ATBM8830) += atbm8830.o
+obj-$(CONFIG_DVB_AU8522) += au8522_common.o
+obj-$(CONFIG_DVB_AU8522_DTV) += au8522_dig.o
+obj-$(CONFIG_DVB_AU8522_V4L) += au8522_decoder.o
+obj-$(CONFIG_DVB_BCM3510) += bcm3510.o
+obj-$(CONFIG_DVB_CX22700) += cx22700.o
+obj-$(CONFIG_DVB_CX22702) += cx22702.o
+obj-$(CONFIG_DVB_CX24110) += cx24110.o
+obj-$(CONFIG_DVB_CX24116) += cx24116.o
+obj-$(CONFIG_DVB_CX24117) += cx24117.o
+obj-$(CONFIG_DVB_CX24120) += cx24120.o
+obj-$(CONFIG_DVB_CX24123) += cx24123.o
+obj-$(CONFIG_DVB_CXD2099) += cxd2099.o
+obj-$(CONFIG_DVB_CXD2820R) += cxd2820r.o
+obj-$(CONFIG_DVB_CXD2841ER) += cxd2841er.o
+obj-$(CONFIG_DVB_CXD2880) += cxd2880/
+obj-$(CONFIG_DVB_DIB3000MB) += dib3000mb.o
+obj-$(CONFIG_DVB_DIB3000MC) += dib3000mc.o dibx000_common.o
+obj-$(CONFIG_DVB_DIB7000M) += dib7000m.o dibx000_common.o
+obj-$(CONFIG_DVB_DIB7000P) += dib7000p.o dibx000_common.o
+obj-$(CONFIG_DVB_DIB8000) += dib8000.o dibx000_common.o
+obj-$(CONFIG_DVB_DIB9000) += dib9000.o dibx000_common.o
+obj-$(CONFIG_DVB_DRX39XYJ) += drx39xyj/
+obj-$(CONFIG_DVB_DRXD) += drxd.o
+obj-$(CONFIG_DVB_DRXK) += drxk.o
+obj-$(CONFIG_DVB_DS3000) += ds3000.o
+obj-$(CONFIG_DVB_DUMMY_FE) += dvb_dummy_fe.o
+obj-$(CONFIG_DVB_EC100) += ec100.o
+obj-$(CONFIG_DVB_GP8PSK_FE) += gp8psk-fe.o
+obj-$(CONFIG_DVB_HELENE) += helene.o
+obj-$(CONFIG_DVB_HORUS3A) += horus3a.o
+obj-$(CONFIG_DVB_ISL6405) += isl6405.o
+obj-$(CONFIG_DVB_ISL6421) += isl6421.o
+obj-$(CONFIG_DVB_ISL6423) += isl6423.o
+obj-$(CONFIG_DVB_IX2505V) += ix2505v.o
+obj-$(CONFIG_DVB_L64781) += l64781.o
+obj-$(CONFIG_DVB_LG2160) += lg2160.o
+obj-$(CONFIG_DVB_LGDT3305) += lgdt3305.o
+obj-$(CONFIG_DVB_LGDT3306A) += lgdt3306a.o
+obj-$(CONFIG_DVB_LGDT330X) += lgdt330x.o
+obj-$(CONFIG_DVB_LGS8GL5) += lgs8gl5.o
+obj-$(CONFIG_DVB_LGS8GXX) += lgs8gxx.o
+obj-$(CONFIG_DVB_LNBH25) += lnbh25.o
+obj-$(CONFIG_DVB_LNBH29) += lnbh29.o
+obj-$(CONFIG_DVB_LNBP21) += lnbp21.o
+obj-$(CONFIG_DVB_LNBP22) += lnbp22.o
+obj-$(CONFIG_DVB_M88DS3103) += m88ds3103.o
+obj-$(CONFIG_DVB_M88RS2000) += m88rs2000.o
+obj-$(CONFIG_DVB_MB86A16) += mb86a16.o
+obj-$(CONFIG_DVB_MB86A20S) += mb86a20s.o
+obj-$(CONFIG_DVB_MN88443X) += mn88443x.o
+obj-$(CONFIG_DVB_MN88472) += mn88472.o
+obj-$(CONFIG_DVB_MN88473) += mn88473.o
+obj-$(CONFIG_DVB_MT312) += mt312.o
+obj-$(CONFIG_DVB_MT352) += mt352.o
+obj-$(CONFIG_DVB_MXL5XX) += mxl5xx.o
+obj-$(CONFIG_DVB_MXL692) += mxl692.o
+obj-$(CONFIG_DVB_NXT200X) += nxt200x.o
+obj-$(CONFIG_DVB_NXT6000) += nxt6000.o
+obj-$(CONFIG_DVB_OR51132) += or51132.o
+obj-$(CONFIG_DVB_OR51211) += or51211.o
+obj-$(CONFIG_DVB_PLL) += dvb-pll.o
+obj-$(CONFIG_DVB_RTL2830) += rtl2830.o
+obj-$(CONFIG_DVB_RTL2832) += rtl2832.o
+obj-$(CONFIG_DVB_RTL2832_SDR) += rtl2832_sdr.o
+obj-$(CONFIG_DVB_S5H1409) += s5h1409.o
+obj-$(CONFIG_DVB_S5H1411) += s5h1411.o
+obj-$(CONFIG_DVB_S5H1420) += s5h1420.o
+obj-$(CONFIG_DVB_S5H1432) += s5h1432.o
+obj-$(CONFIG_DVB_S921) += s921.o
+obj-$(CONFIG_DVB_SI2165) += si2165.o
+obj-$(CONFIG_DVB_SI2168) += si2168.o
+obj-$(CONFIG_DVB_SI21XX) += si21xx.o
+obj-$(CONFIG_DVB_SP2) += sp2.o
+obj-$(CONFIG_DVB_SP887X) += sp887x.o
+obj-$(CONFIG_DVB_STB0899) += stb0899.o
+obj-$(CONFIG_DVB_STB6000) += stb6000.o
+obj-$(CONFIG_DVB_STB6100) += stb6100.o
+obj-$(CONFIG_DVB_STV0288) += stv0288.o
+obj-$(CONFIG_DVB_STV0297) += stv0297.o
+obj-$(CONFIG_DVB_STV0299) += stv0299.o
+obj-$(CONFIG_DVB_STV0367) += stv0367.o
+obj-$(CONFIG_DVB_STV0900) += stv0900.o
+obj-$(CONFIG_DVB_STV090x) += stv090x.o
+obj-$(CONFIG_DVB_STV0910) += stv0910.o
+obj-$(CONFIG_DVB_STV6110) += stv6110.o
+obj-$(CONFIG_DVB_STV6110x) += stv6110x.o
+obj-$(CONFIG_DVB_STV6111) += stv6111.o
+obj-$(CONFIG_DVB_TC90522) += tc90522.o
+obj-$(CONFIG_DVB_TDA10021) += tda10021.o
+obj-$(CONFIG_DVB_TDA10023) += tda10023.o
+obj-$(CONFIG_DVB_TDA10048) += tda10048.o
+obj-$(CONFIG_DVB_TDA1004X) += tda1004x.o
+obj-$(CONFIG_DVB_TDA10071) += tda10071.o
+obj-$(CONFIG_DVB_TDA10086) += tda10086.o
+obj-$(CONFIG_DVB_TDA18271C2DD) += tda18271c2dd.o
+obj-$(CONFIG_DVB_TDA665x) += tda665x.o
+obj-$(CONFIG_DVB_TDA8083) += tda8083.o
+obj-$(CONFIG_DVB_TDA8261) += tda8261.o
+obj-$(CONFIG_DVB_TDA826X) += tda826x.o
+obj-$(CONFIG_DVB_TS2020) += ts2020.o
+obj-$(CONFIG_DVB_TUA6100) += tua6100.o
+obj-$(CONFIG_DVB_TUNER_CX24113) += cx24113.o
+obj-$(CONFIG_DVB_TUNER_DIB0070) += dib0070.o
+obj-$(CONFIG_DVB_TUNER_DIB0090) += dib0090.o
+obj-$(CONFIG_DVB_TUNER_ITD1000) += itd1000.o
+obj-$(CONFIG_DVB_VES1820) += ves1820.o
+obj-$(CONFIG_DVB_VES1X93) += ves1x93.o
+obj-$(CONFIG_DVB_ZD1301_DEMOD) += zd1301_demod.o
+obj-$(CONFIG_DVB_ZL10036) += zl10036.o
+obj-$(CONFIG_DVB_ZL10039) += zl10039.o
+obj-$(CONFIG_DVB_ZL10353) += zl10353.o