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/input/Kconfig | 204 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 204 insertions(+) create mode 100644 drivers/input/Kconfig (limited to 'drivers/input/Kconfig') diff --git a/drivers/input/Kconfig b/drivers/input/Kconfig new file mode 100644 index 000000000..88ecdf521 --- /dev/null +++ b/drivers/input/Kconfig @@ -0,0 +1,204 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# Input device configuration +# + +menu "Input device support" + +config INPUT + tristate "Generic input layer (needed for keyboard, mouse, ...)" if EXPERT + default y + help + Say Y here if you have any input device (mouse, keyboard, tablet, + joystick, steering wheel ...) connected to your system and want + it to be available to applications. This includes standard PS/2 + keyboard and mouse. + + Say N here if you have a headless (no monitor, no keyboard) system. + + More information is available: + + If unsure, say Y. + + To compile this driver as a module, choose M here: the + module will be called input. + +if INPUT + +config INPUT_LEDS + tristate "Export input device LEDs in sysfs" + depends on LEDS_CLASS + default INPUT + help + Say Y here if you would like to export LEDs on input devices + as standard LED class devices in sysfs. + + If unsure, say Y. + + To compile this driver as a module, choose M here: the + module will be called input-leds. + +config INPUT_FF_MEMLESS + tristate "Support for memoryless force-feedback devices" + help + Say Y here if you have memoryless force-feedback input device + such as Logitech WingMan Force 3D, ThrustMaster FireStorm Dual + Power 2, or similar. You will also need to enable hardware-specific + driver. + + If unsure, say N. + + To compile this driver as a module, choose M here: the + module will be called ff-memless. + +config INPUT_SPARSEKMAP + tristate "Sparse keymap support library" + help + Say Y here if you are using a driver for an input + device that uses sparse keymap. This option is only + useful for out-of-tree drivers since in-tree drivers + select it automatically. + + If unsure, say N. + + To compile this driver as a module, choose M here: the + module will be called sparse-keymap. + +config INPUT_MATRIXKMAP + tristate "Matrix keymap support library" + help + Say Y here if you are using a driver for an input + device that uses matrix keymap. This option is only + useful for out-of-tree drivers since in-tree drivers + select it automatically. + + If unsure, say N. + + To compile this driver as a module, choose M here: the + module will be called matrix-keymap. + +config INPUT_VIVALDIFMAP + tristate + help + ChromeOS Vivaldi keymap support library. This is a hidden + option so that drivers can use common code to parse and + expose the vivaldi function row keymap. + +comment "Userland interfaces" + +config INPUT_MOUSEDEV + tristate "Mouse interface" + help + Say Y here if you want your mouse to be accessible as char devices + 13:32+ - /dev/input/mouseX and 13:63 - /dev/input/mice as an + emulated IntelliMouse Explorer PS/2 mouse. That way, all user space + programs (including SVGAlib, GPM and X) will be able to use your + mouse. + + If unsure, say Y. + + To compile this driver as a module, choose M here: the + module will be called mousedev. + +config INPUT_MOUSEDEV_PSAUX + bool "Provide legacy /dev/psaux device" + depends on INPUT_MOUSEDEV + help + Say Y here if you want your mouse also be accessible as char device + 10:1 - /dev/psaux. The data available through /dev/psaux is exactly + the same as the data from /dev/input/mice. + + If unsure, say Y. + +config INPUT_MOUSEDEV_SCREEN_X + int "Horizontal screen resolution" + depends on INPUT_MOUSEDEV + default "1024" + help + If you're using a digitizer, or a graphic tablet, and want to use + it as a mouse then the mousedev driver needs to know the X window + screen resolution you are using to correctly scale the data. If + you're not using a digitizer, this value is ignored. + +config INPUT_MOUSEDEV_SCREEN_Y + int "Vertical screen resolution" + depends on INPUT_MOUSEDEV + default "768" + help + If you're using a digitizer, or a graphic tablet, and want to use + it as a mouse then the mousedev driver needs to know the X window + screen resolution you are using to correctly scale the data. If + you're not using a digitizer, this value is ignored. + +config INPUT_JOYDEV + tristate "Joystick interface" + help + Say Y here if you want your joystick or gamepad to be + accessible as char device 13:0+ - /dev/input/jsX device. + + If unsure, say Y. + + More information is available: + + To compile this driver as a module, choose M here: the + module will be called joydev. + +config INPUT_EVDEV + tristate "Event interface" + help + Say Y here if you want your input device events be accessible + under char device 13:64+ - /dev/input/eventX in a generic way. + + To compile this driver as a module, choose M here: the + module will be called evdev. + +config INPUT_KUNIT_TEST + tristate "KUnit tests for Input" if !KUNIT_ALL_TESTS + depends on INPUT && KUNIT + default KUNIT_ALL_TESTS + help + Say Y here if you want to build the KUnit tests for the input + subsystem. + + If in doubt, say "N". + +config INPUT_APMPOWER + tristate "Input Power Event -> APM Bridge" if EXPERT + depends on INPUT && APM_EMULATION + help + Say Y here if you want suspend key events to trigger a user + requested suspend through APM. This is useful on embedded + systems where such behaviour is desired without userspace + interaction. If unsure, say N. + + To compile this driver as a module, choose M here: the + module will be called apm-power. + +comment "Input Device Drivers" + +source "drivers/input/keyboard/Kconfig" + +source "drivers/input/mouse/Kconfig" + +source "drivers/input/joystick/Kconfig" + +source "drivers/input/tablet/Kconfig" + +source "drivers/input/touchscreen/Kconfig" + +source "drivers/input/misc/Kconfig" + +source "drivers/input/rmi4/Kconfig" + +endif + +menu "Hardware I/O ports" + +source "drivers/input/serio/Kconfig" + +source "drivers/input/gameport/Kconfig" + +endmenu + +endmenu + -- cgit v1.3.1