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 --- drivers/soc/qcom/Makefile | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) create mode 100644 drivers/soc/qcom/Makefile (limited to 'drivers/soc/qcom/Makefile') diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile new file mode 100644 index 000000000..798643be3 --- /dev/null +++ b/drivers/soc/qcom/Makefile @@ -0,0 +1,43 @@ +# SPDX-License-Identifier: GPL-2.0 +CFLAGS_rpmh-rsc.o := -I$(src) +CFLAGS_qcom_aoss.o := -I$(src) +obj-$(CONFIG_QCOM_AOSS_QMP) += qcom_aoss.o +obj-$(CONFIG_QCOM_GENI_SE) += qcom-geni-se.o +obj-$(CONFIG_QCOM_COMMAND_DB) += cmd-db.o +obj-$(CONFIG_QCOM_GSBI) += qcom_gsbi.o +obj-$(CONFIG_QCOM_MDT_LOADER) += mdt_loader.o +obj-$(CONFIG_QCOM_OCMEM) += ocmem.o +obj-$(CONFIG_QCOM_PD_MAPPER) += qcom_pd_mapper.o +obj-$(CONFIG_QCOM_PDR_HELPERS) += pdr_interface.o +obj-$(CONFIG_QCOM_PDR_MSG) += qcom_pdr_msg.o +obj-$(CONFIG_QCOM_PMIC_GLINK) += pmic_glink.o +obj-$(CONFIG_QCOM_PMIC_GLINK) += pmic_glink_altmode.o +obj-$(CONFIG_QCOM_PMIC_PDCHARGER_ULOG) += pmic_pdcharger_ulog.o +CFLAGS_pmic_pdcharger_ulog.o := -I$(src) +obj-$(CONFIG_QCOM_QMI_HELPERS) += qmi_helpers.o +qmi_helpers-y += qmi_encdec.o qmi_interface.o +obj-$(CONFIG_QCOM_RAMP_CTRL) += ramp_controller.o +obj-$(CONFIG_QCOM_RMTFS_MEM) += rmtfs_mem.o +obj-$(CONFIG_QCOM_RPM_MASTER_STATS) += rpm_master_stats.o +obj-$(CONFIG_QCOM_RPMH) += qcom_rpmh.o +qcom_rpmh-y += rpmh-rsc.o +qcom_rpmh-y += rpmh.o +obj-$(CONFIG_QCOM_SMD_RPM) += rpm-proc.o smd-rpm.o +qcom_smem-y += smem.o smem_dramc.o +obj-$(CONFIG_QCOM_SMEM) += qcom_smem.o +obj-$(CONFIG_QCOM_SMEM_STATE) += smem_state.o +CFLAGS_smp2p.o := -I$(src) +obj-$(CONFIG_QCOM_SMP2P) += smp2p.o +obj-$(CONFIG_QCOM_SMSM) += smsm.o +obj-$(CONFIG_QCOM_SOCINFO) += socinfo.o +obj-$(CONFIG_QCOM_SPM) += spm.o +obj-$(CONFIG_QCOM_STATS) += qcom_stats.o +obj-$(CONFIG_QCOM_WCNSS_CTRL) += wcnss_ctrl.o +obj-$(CONFIG_QCOM_APR) += apr.o +obj-$(CONFIG_QCOM_LLCC) += llcc-qcom.o +obj-$(CONFIG_QCOM_KRYO_L2_ACCESSORS) += kryo-l2-accessors.o +obj-$(CONFIG_QCOM_ICC_BWMON) += icc-bwmon.o +qcom_ice-objs += ice.o +obj-$(CONFIG_QCOM_INLINE_CRYPTO_ENGINE) += qcom_ice.o +obj-$(CONFIG_QCOM_PBS) += qcom-pbs.o +obj-$(CONFIG_QCOM_UBWC_CONFIG) += ubwc_config.o -- cgit v1.3.1