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/firmware/Makefile | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) create mode 100644 drivers/firmware/Makefile (limited to 'drivers/firmware/Makefile') diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile new file mode 100644 index 000000000..be46f1e1d --- /dev/null +++ b/drivers/firmware/Makefile @@ -0,0 +1,41 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for the linux kernel. +# +obj-$(CONFIG_ARM_SCPI_PROTOCOL) += arm_scpi.o +obj-$(CONFIG_ARM_SDE_INTERFACE) += arm_sdei.o +obj-$(CONFIG_ARM_SDEI_NMI) += arm_sdei_nmi.o +obj-$(CONFIG_DMI) += dmi_scan.o +obj-$(CONFIG_DMI_SYSFS) += dmi-sysfs.o +obj-$(CONFIG_EDD) += edd.o +obj-$(CONFIG_DMIID) += dmi-id.o +obj-$(CONFIG_INTEL_STRATIX10_SERVICE) += stratix10-svc.o +obj-$(CONFIG_INTEL_STRATIX10_RSU) += stratix10-rsu.o +obj-$(CONFIG_ISCSI_IBFT_FIND) += iscsi_ibft_find.o +obj-$(CONFIG_ISCSI_IBFT) += iscsi_ibft.o +obj-$(CONFIG_FIRMWARE_MEMMAP) += memmap.o +obj-$(CONFIG_MTK_ADSP_IPC) += mtk-adsp-ipc.o +obj-$(CONFIG_RASPBERRYPI_FIRMWARE) += raspberrypi.o +obj-$(CONFIG_FW_CFG_SYSFS) += qemu_fw_cfg.o +obj-$(CONFIG_SYSFB) += sysfb.o +obj-$(CONFIG_SYSFB_SIMPLEFB) += sysfb_simplefb.o +obj-$(CONFIG_TH1520_AON_PROTOCOL) += thead,th1520-aon.o +obj-$(CONFIG_TI_SCI_PROTOCOL) += ti_sci.o +obj-$(CONFIG_TRUSTED_FOUNDATIONS) += trusted_foundations.o +obj-$(CONFIG_TURRIS_MOX_RWTM) += turris-mox-rwtm.o + +obj-y += arm_ffa/ +obj-y += arm_scmi/ +obj-y += broadcom/ +obj-y += cirrus/ +obj-y += meson/ +obj-y += microchip/ +obj-$(CONFIG_GOOGLE_FIRMWARE) += google/ +obj-y += efi/ +obj-y += imx/ +obj-y += psci/ +obj-y += qcom/ +obj-y += samsung/ +obj-y += smccc/ +obj-y += tegra/ +obj-y += xilinx/ -- cgit v1.3.1