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/hid/hid-rapoo.c | 101 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 101 insertions(+) create mode 100644 drivers/hid/hid-rapoo.c (limited to 'drivers/hid/hid-rapoo.c') diff --git a/drivers/hid/hid-rapoo.c b/drivers/hid/hid-rapoo.c new file mode 100644 index 000000000..5c9c396fa --- /dev/null +++ b/drivers/hid/hid-rapoo.c @@ -0,0 +1,101 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include +#include +#include + +#include "hid-ids.h" + +#define RAPOO_BTN_BACK 0x08 +#define RAPOO_BTN_FORWARD 0x10 + +static const struct hid_device_id rapoo_devices[] = { + { HID_USB_DEVICE(USB_VENDOR_ID_RAPOO, USB_DEVICE_ID_RAPOO_2_4G_RECEIVER) }, + { } +}; +MODULE_DEVICE_TABLE(hid, rapoo_devices); + +static int rapoo_probe(struct hid_device *hdev, const struct hid_device_id *id) +{ + int ret; + struct input_dev *input; + + ret = hid_parse(hdev); + if (ret) { + hid_err(hdev, "parse failed\n"); + return ret; + } + + ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT); + if (ret) { + hid_err(hdev, "start failed\n"); + return ret; + } + + if (hid_is_usb(hdev)) { + struct usb_interface *intf = to_usb_interface(hdev->dev.parent); + + if (intf->cur_altsetting->desc.bInterfaceNumber != 1) + return 0; + } + + input = devm_input_allocate_device(&hdev->dev); + if (!input) + return -ENOMEM; + + input->name = "Rapoo 2.4G Wireless Mouse"; + input->phys = "rapoo/input1"; + input->id.bustype = hdev->bus; + input->id.vendor = hdev->vendor; + input->id.product = hdev->product; + input->id.version = hdev->version; + + __set_bit(EV_KEY, input->evbit); + __set_bit(KEY_BACK, input->keybit); + __set_bit(KEY_FORWARD, input->keybit); + + ret = input_register_device(input); + if (ret) + return ret; + + hid_set_drvdata(hdev, input); + + return ret; +} + +static int rapoo_raw_event(struct hid_device *hdev, struct hid_report *report, u8 *data, int size) +{ + struct input_dev *input = hid_get_drvdata(hdev); + + if (!input) + return 0; + + if (report->id == 1 && size >= 2) { + u8 btn = data[1]; + + input_report_key(input, KEY_BACK, btn & RAPOO_BTN_BACK); + input_report_key(input, KEY_FORWARD, btn & RAPOO_BTN_FORWARD); + input_sync(input); + return 1; + } + + return 0; +} + +static struct hid_driver rapoo_driver = { + .name = "hid-rapoo", + .id_table = rapoo_devices, + .probe = rapoo_probe, + .raw_event = rapoo_raw_event, +}; + +module_hid_driver(rapoo_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Nguyen Dinh Dang Duong "); +MODULE_DESCRIPTION("RAPOO 2.4G Wireless Device Driver"); + -- cgit v1.3.1