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 --- include/trace/events/sof.h | 121 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 121 insertions(+) create mode 100644 include/trace/events/sof.h (limited to 'include/trace/events/sof.h') diff --git a/include/trace/events/sof.h b/include/trace/events/sof.h new file mode 100644 index 000000000..3061423c0 --- /dev/null +++ b/include/trace/events/sof.h @@ -0,0 +1,121 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright(c) 2022 Intel Corporation + * + * Author: Noah Klayman + */ + +#undef TRACE_SYSTEM +#define TRACE_SYSTEM sof + +#if !defined(_TRACE_SOF_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_SOF_H +#include +#include +#include +#include "../../../sound/soc/sof/sof-audio.h" + +DECLARE_EVENT_CLASS(sof_widget_template, + TP_PROTO(struct snd_sof_widget *swidget), + TP_ARGS(swidget), + TP_STRUCT__entry( + __string(name, swidget->widget->name) + __field(int, use_count) + ), + TP_fast_assign( + __assign_str(name); + __entry->use_count = swidget->use_count; + ), + TP_printk("name=%s use_count=%d", __get_str(name), __entry->use_count) +); + +DEFINE_EVENT(sof_widget_template, sof_widget_setup, + TP_PROTO(struct snd_sof_widget *swidget), + TP_ARGS(swidget) +); + +DEFINE_EVENT(sof_widget_template, sof_widget_free, + TP_PROTO(struct snd_sof_widget *swidget), + TP_ARGS(swidget) +); + +TRACE_EVENT(sof_ipc3_period_elapsed_position, + TP_PROTO(struct snd_sof_dev *sdev, struct sof_ipc_stream_posn *posn), + TP_ARGS(sdev, posn), + TP_STRUCT__entry( + __string(device_name, dev_name(sdev->dev)) + __field(u64, host_posn) + __field(u64, dai_posn) + __field(u64, wallclock) + ), + TP_fast_assign( + __assign_str(device_name); + __entry->host_posn = posn->host_posn; + __entry->dai_posn = posn->dai_posn; + __entry->wallclock = posn->wallclock; + ), + TP_printk("device_name=%s host_posn=%#llx dai_posn=%#llx wallclock=%#llx", + __get_str(device_name), __entry->host_posn, __entry->dai_posn, + __entry->wallclock) +); + +TRACE_EVENT(sof_pcm_pointer_position, + TP_PROTO(struct snd_sof_dev *sdev, + struct snd_sof_pcm *spcm, + struct snd_pcm_substream *substream, + snd_pcm_uframes_t dma_posn, + snd_pcm_uframes_t dai_posn + ), + TP_ARGS(sdev, spcm, substream, dma_posn, dai_posn), + TP_STRUCT__entry( + __string(device_name, dev_name(sdev->dev)) + __field(u32, pcm_id) + __field(int, stream) + __field(unsigned long, dma_posn) + __field(unsigned long, dai_posn) + ), + TP_fast_assign( + __assign_str(device_name); + __entry->pcm_id = le32_to_cpu(spcm->pcm.pcm_id); + __entry->stream = substream->stream; + __entry->dma_posn = dma_posn; + __entry->dai_posn = dai_posn; + ), + TP_printk("device_name=%s pcm_id=%d stream=%d dma_posn=%lu dai_posn=%lu", + __get_str(device_name), __entry->pcm_id, __entry->stream, + __entry->dma_posn, __entry->dai_posn) +); + +TRACE_EVENT(sof_stream_position_ipc_rx, + TP_PROTO(struct device *dev), + TP_ARGS(dev), + TP_STRUCT__entry( + __string(device_name, dev_name(dev)) + ), + TP_fast_assign( + __assign_str(device_name); + ), + TP_printk("device_name=%s", __get_str(device_name)) +); + +TRACE_EVENT(sof_ipc4_fw_config, + TP_PROTO(struct snd_sof_dev *sdev, char *key, u32 value), + TP_ARGS(sdev, key, value), + TP_STRUCT__entry( + __string(device_name, dev_name(sdev->dev)) + __string(key, key) + __field(u32, value) + ), + TP_fast_assign( + __assign_str(device_name); + __assign_str(key); + __entry->value = value; + ), + TP_printk("device_name=%s key=%s value=%d", + __get_str(device_name), __get_str(key), __entry->value) +); + +#endif /* _TRACE_SOF_H */ + +/* This part must be outside protection */ +#include -- cgit v1.3.1