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/Makefile | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 67 insertions(+) create mode 100644 drivers/usb/Makefile (limited to 'drivers/usb/Makefile') diff --git a/drivers/usb/Makefile b/drivers/usb/Makefile new file mode 100644 index 000000000..eecbd631f --- /dev/null +++ b/drivers/usb/Makefile @@ -0,0 +1,67 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for the kernel USB device drivers. +# + +# Object files in subdirectories + +obj-$(CONFIG_USB_COMMON) += common/ +obj-$(CONFIG_USB) += core/ +obj-$(CONFIG_USB_SUPPORT) += phy/ + +obj-$(CONFIG_USB_DWC3) += dwc3/ +obj-$(CONFIG_USB_DWC2) += dwc2/ +obj-$(CONFIG_USB_ISP1760) += isp1760/ + +obj-$(CONFIG_USB_CDNS_SUPPORT) += cdns3/ + +obj-$(CONFIG_USB_FOTG210) += fotg210/ + +obj-$(CONFIG_USB_MON) += mon/ +obj-$(CONFIG_USB_MTU3) += mtu3/ + +obj-$(CONFIG_USB_PCI) += host/ +obj-$(CONFIG_USB_EHCI_HCD) += host/ +obj-$(CONFIG_USB_ISP116X_HCD) += host/ +obj-$(CONFIG_USB_OHCI_HCD) += host/ +obj-$(CONFIG_USB_UHCI_HCD) += host/ +obj-$(CONFIG_USB_FHCI_HCD) += host/ +obj-$(CONFIG_USB_XHCI_HCD) += host/ +obj-$(CONFIG_USB_SL811_HCD) += host/ +obj-$(CONFIG_USB_R8A66597_HCD) += host/ +obj-$(CONFIG_USB_FSL_USB2) += host/ +obj-$(CONFIG_USB_FOTG210_HCD) += host/ +obj-$(CONFIG_USB_MAX3421_HCD) += host/ +obj-$(CONFIG_USB_XEN_HCD) += host/ + +obj-$(CONFIG_USB_C67X00_HCD) += c67x00/ + +obj-$(CONFIG_USB_ACM) += class/ +obj-$(CONFIG_USB_PRINTER) += class/ +obj-$(CONFIG_USB_WDM) += class/ +obj-$(CONFIG_USB_TMC) += class/ + +obj-$(CONFIG_USB_STORAGE) += storage/ +obj-$(CONFIG_USB) += storage/ + +obj-$(CONFIG_USB_MDC800) += image/ +obj-$(CONFIG_USB_MICROTEK) += image/ + +obj-$(CONFIG_USB_SERIAL) += serial/ + +obj-$(CONFIG_USB) += misc/ +obj-$(CONFIG_EARLY_PRINTK_USB) += early/ + +obj-$(CONFIG_USB_ATM) += atm/ +obj-$(CONFIG_USB_SPEEDTOUCH) += atm/ + +obj-$(CONFIG_USB_MUSB_HDRC) += musb/ +obj-$(CONFIG_USB_CHIPIDEA) += chipidea/ +obj-$(CONFIG_USB_RENESAS_USBHS) += renesas_usbhs/ +obj-$(CONFIG_USB_GADGET) += gadget/ + +obj-$(CONFIG_USBIP_CORE) += usbip/ + +obj-$(CONFIG_TYPEC) += typec/ + +obj-$(CONFIG_USB_ROLE_SWITCH) += roles/ -- cgit v1.3.1