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/usb/dwc3/Makefile | 63 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 drivers/usb/dwc3/Makefile (limited to 'drivers/usb/dwc3/Makefile') diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile new file mode 100644 index 000000000..f37971197 --- /dev/null +++ b/drivers/usb/dwc3/Makefile @@ -0,0 +1,63 @@ +# SPDX-License-Identifier: GPL-2.0 +# define_trace.h needs to know how to find our header +CFLAGS_trace.o := -I$(src) + +obj-$(CONFIG_USB_DWC3) += dwc3.o + +dwc3-y := core.o + +ifneq ($(CONFIG_TRACING),) + dwc3-y += trace.o +endif + +ifneq ($(filter y,$(CONFIG_USB_DWC3_HOST) $(CONFIG_USB_DWC3_DUAL_ROLE)),) + dwc3-y += host.o +endif + +ifneq ($(filter y,$(CONFIG_USB_DWC3_GADGET) $(CONFIG_USB_DWC3_DUAL_ROLE)),) + dwc3-y += gadget.o ep0.o +endif + +ifneq ($(CONFIG_USB_DWC3_DUAL_ROLE),) + dwc3-y += drd.o +endif + +ifneq ($(CONFIG_USB_DWC3_ULPI),) + dwc3-y += ulpi.o +endif + +ifneq ($(CONFIG_DEBUG_FS),) + dwc3-y += debugfs.o +endif + +## +# Platform-specific glue layers go here +# +# NOTICE: Make sure your glue layer doesn't depend on anything +# which is arch-specific and that it compiles on all situations. +# +# We want to keep this requirement in order to be able to compile +# the entire driver (with all its glue layers) on several architectures +# and make sure it compiles fine. This will also help with allmodconfig +# and allyesconfig builds. +## + +obj-$(CONFIG_USB_DWC3_AM62) += dwc3-am62.o +obj-$(CONFIG_USB_DWC3_APPLE) += dwc3-apple.o +obj-$(CONFIG_USB_DWC3_OMAP) += dwc3-omap.o +obj-$(CONFIG_USB_DWC3_EXYNOS) += dwc3-exynos.o +obj-$(CONFIG_USB_DWC3_PCI) += dwc3-pci.o +obj-$(CONFIG_USB_DWC3_HAPS) += dwc3-haps.o +obj-$(CONFIG_USB_DWC3_KEYSTONE) += dwc3-keystone.o +obj-$(CONFIG_USB_DWC3_MESON_G12A) += dwc3-meson-g12a.o +obj-$(CONFIG_USB_DWC3_OF_SIMPLE) += dwc3-of-simple.o +obj-$(CONFIG_USB_DWC3_ST) += dwc3-st.o +obj-$(CONFIG_USB_DWC3_QCOM) += dwc3-qcom.o +obj-$(CONFIG_USB_DWC3_QCOM) += dwc3-qcom-legacy.o +obj-$(CONFIG_USB_DWC3_IMX8MP) += dwc3-imx8mp.o +obj-$(CONFIG_USB_DWC3_IMX) += dwc3-imx.o +obj-$(CONFIG_USB_DWC3_XILINX) += dwc3-xilinx.o +obj-$(CONFIG_USB_DWC3_OCTEON) += dwc3-octeon.o +obj-$(CONFIG_USB_DWC3_RTK) += dwc3-rtk.o +obj-$(CONFIG_USB_DWC3_GENERIC_PLAT) += dwc3-generic-plat.o +obj-$(CONFIG_USB_DWC3_GOOGLE) += dwc3-google.o -- cgit v1.3.1