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 --- sound/soc/codecs/chv3-codec.c | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 sound/soc/codecs/chv3-codec.c (limited to 'sound/soc/codecs/chv3-codec.c') diff --git a/sound/soc/codecs/chv3-codec.c b/sound/soc/codecs/chv3-codec.c new file mode 100644 index 000000000..40020500b --- /dev/null +++ b/sound/soc/codecs/chv3-codec.c @@ -0,0 +1,42 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include +#include + +static struct snd_soc_dai_driver chv3_codec_dai = { + .name = "chv3-codec-hifi", + .capture = { + .stream_name = "Capture", + .channels_min = 8, + .channels_max = 8, + .rates = SNDRV_PCM_RATE_CONTINUOUS, + .formats = SNDRV_PCM_FMTBIT_S32_LE, + }, +}; + +static const struct snd_soc_component_driver soc_component_dev_chv3_codec = { +}; + +static int chv3_codec_probe(struct platform_device *pdev) +{ + return devm_snd_soc_register_component(&pdev->dev, + &soc_component_dev_chv3_codec, &chv3_codec_dai, 1); +} + +static const struct of_device_id chv3_codec_of_match[] = { + { .compatible = "google,chv3-codec", }, + { } +}; +MODULE_DEVICE_TABLE(of, chv3_codec_of_match); + +static struct platform_driver chv3_codec_platform_driver = { + .driver = { + .name = "chv3-codec", + .of_match_table = chv3_codec_of_match, + }, + .probe = chv3_codec_probe, +}; +module_platform_driver(chv3_codec_platform_driver); + +MODULE_DESCRIPTION("ASoC Chameleon v3 codec driver"); +MODULE_AUTHOR("Pawel Anikiel "); +MODULE_LICENSE("GPL"); -- cgit v1.3.1