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/joystick/maplecontrol.c | 194 ++++++++++++++++++++++++++++++++++ 1 file changed, 194 insertions(+) create mode 100644 drivers/input/joystick/maplecontrol.c (limited to 'drivers/input/joystick/maplecontrol.c') diff --git a/drivers/input/joystick/maplecontrol.c b/drivers/input/joystick/maplecontrol.c new file mode 100644 index 000000000..6293b6e81 --- /dev/null +++ b/drivers/input/joystick/maplecontrol.c @@ -0,0 +1,194 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * SEGA Dreamcast controller driver + * Based on drivers/usb/iforce.c + * + * Copyright Yaegashi Takeshi, 2001 + * Adrian McMenamin, 2008 - 2009 + */ + +#include +#include +#include +#include +#include +#include +#include + +MODULE_AUTHOR("Adrian McMenamin "); +MODULE_DESCRIPTION("SEGA Dreamcast controller driver"); +MODULE_LICENSE("GPL"); + +struct dc_pad { + struct input_dev *dev; + struct maple_device *mdev; +}; + +static void dc_pad_callback(struct mapleq *mq) +{ + unsigned short buttons; + struct maple_device *mapledev = mq->dev; + struct dc_pad *pad = maple_get_drvdata(mapledev); + struct input_dev *dev = pad->dev; + unsigned char *res = mq->recvbuf->buf; + + buttons = ~le16_to_cpup((__le16 *)(res + 8)); + + input_report_abs(dev, ABS_HAT0Y, + (buttons & 0x0010 ? -1 : 0) + (buttons & 0x0020 ? 1 : 0)); + input_report_abs(dev, ABS_HAT0X, + (buttons & 0x0040 ? -1 : 0) + (buttons & 0x0080 ? 1 : 0)); + input_report_abs(dev, ABS_HAT1Y, + (buttons & 0x1000 ? -1 : 0) + (buttons & 0x2000 ? 1 : 0)); + input_report_abs(dev, ABS_HAT1X, + (buttons & 0x4000 ? -1 : 0) + (buttons & 0x8000 ? 1 : 0)); + + input_report_key(dev, BTN_C, buttons & 0x0001); + input_report_key(dev, BTN_B, buttons & 0x0002); + input_report_key(dev, BTN_A, buttons & 0x0004); + input_report_key(dev, BTN_START, buttons & 0x0008); + input_report_key(dev, BTN_Z, buttons & 0x0100); + input_report_key(dev, BTN_Y, buttons & 0x0200); + input_report_key(dev, BTN_X, buttons & 0x0400); + input_report_key(dev, BTN_SELECT, buttons & 0x0800); + + input_report_abs(dev, ABS_GAS, res[10]); + input_report_abs(dev, ABS_BRAKE, res[11]); + input_report_abs(dev, ABS_X, res[12]); + input_report_abs(dev, ABS_Y, res[13]); + input_report_abs(dev, ABS_RX, res[14]); + input_report_abs(dev, ABS_RY, res[15]); +} + +static int dc_pad_open(struct input_dev *dev) +{ + struct dc_pad *pad = dev_get_platdata(&dev->dev); + + maple_getcond_callback(pad->mdev, dc_pad_callback, HZ/20, + MAPLE_FUNC_CONTROLLER); + + return 0; +} + +static void dc_pad_close(struct input_dev *dev) +{ + struct dc_pad *pad = dev_get_platdata(&dev->dev); + + maple_getcond_callback(pad->mdev, dc_pad_callback, 0, + MAPLE_FUNC_CONTROLLER); +} + +/* allow the controller to be used */ +static int probe_maple_controller(struct device *dev) +{ + static const short btn_bit[32] = { + BTN_C, BTN_B, BTN_A, BTN_START, -1, -1, -1, -1, + BTN_Z, BTN_Y, BTN_X, BTN_SELECT, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, + }; + + static const short abs_bit[32] = { + -1, -1, -1, -1, ABS_HAT0Y, ABS_HAT0Y, ABS_HAT0X, ABS_HAT0X, + -1, -1, -1, -1, ABS_HAT1Y, ABS_HAT1Y, ABS_HAT1X, ABS_HAT1X, + ABS_GAS, ABS_BRAKE, ABS_X, ABS_Y, ABS_RX, ABS_RY, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, + }; + + struct maple_device *mdev = to_maple_dev(dev); + struct maple_driver *mdrv = to_maple_driver(dev->driver); + int i, error; + struct dc_pad *pad; + struct input_dev *idev; + unsigned long data = be32_to_cpu(mdev->devinfo.function_data[0]); + + pad = kzalloc_obj(*pad); + idev = input_allocate_device(); + if (!pad || !idev) { + error = -ENOMEM; + goto fail; + } + + pad->dev = idev; + pad->mdev = mdev; + + maple_set_drvdata(mdev, pad); + + idev->open = dc_pad_open; + idev->close = dc_pad_close; + + for (i = 0; i < 32; i++) { + if (data & (1 << i)) { + if (btn_bit[i] >= 0) + __set_bit(btn_bit[i], idev->keybit); + else if (abs_bit[i] >= 0) + __set_bit(abs_bit[i], idev->absbit); + } + } + + if (idev->keybit[BIT_WORD(BTN_JOYSTICK)]) + idev->evbit[0] |= BIT_MASK(EV_KEY); + + if (idev->absbit[0]) + idev->evbit[0] |= BIT_MASK(EV_ABS); + + for (i = ABS_X; i <= ABS_BRAKE; i++) + input_set_abs_params(idev, i, 0, 255, 0, 0); + + for (i = ABS_HAT0X; i <= ABS_HAT3Y; i++) + input_set_abs_params(idev, i, 1, -1, 0, 0); + + idev->dev.platform_data = pad; + idev->dev.parent = &mdev->dev; + idev->name = mdev->product_name; + idev->id.bustype = BUS_HOST; + + error = input_register_device(idev); + if (error) + goto fail; + + mdev->driver = mdrv; + + return 0; + +fail: + input_free_device(idev); + kfree(pad); + maple_set_drvdata(mdev, NULL); + return error; +} + +static int remove_maple_controller(struct device *dev) +{ + struct maple_device *mdev = to_maple_dev(dev); + struct dc_pad *pad = maple_get_drvdata(mdev); + + mdev->callback = NULL; + input_unregister_device(pad->dev); + maple_set_drvdata(mdev, NULL); + kfree(pad); + + return 0; +} + +static struct maple_driver dc_pad_driver = { + .function = MAPLE_FUNC_CONTROLLER, + .drv = { + .name = "Dreamcast_controller", + .probe = probe_maple_controller, + .remove = remove_maple_controller, + }, +}; + +static int __init dc_pad_init(void) +{ + return maple_driver_register(&dc_pad_driver); +} + +static void __exit dc_pad_exit(void) +{ + maple_driver_unregister(&dc_pad_driver); +} + +module_init(dc_pad_init); +module_exit(dc_pad_exit); -- cgit v1.3.1