sched/cache: Keep nr_pref_llc_running in the runnable domain, to fix LLC mis-scheduling buggrafted

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 <zhanxusheng@xiaomi.com>
Suggested-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Kayra Cizmeci <kayracizmeci@gmail.com>
Cc: <stable@kernel.org> # v7.2.x
Link: https://patch.msgid.link/06af61afedac32e6477f57feb4d658f6c411c3af.1790035273.git.tim.c.chen@linux.intel.com

1 files changed, 205 insertions, 0 deletions

diff --git a/include/sound/sof/dai-intel.h b/include/sound/sof/dai-intel.h
new file mode 100644
index 000000000..e4e710b43
--- /dev/null
+++ b/include/sound/sof/dai-intel.h
@@ -0,0 +1,205 @@
+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause) */
+/*
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * Copyright(c) 2018 Intel Corporation
+ */
+
+#ifndef __INCLUDE_SOUND_SOF_DAI_INTEL_H__
+#define __INCLUDE_SOUND_SOF_DAI_INTEL_H__
+
+#include <sound/sof/header.h>
+
+ /* ssc1: TINTE */
+#define SOF_DAI_INTEL_SSP_QUIRK_TINTE		(1 << 0)
+ /* ssc1: PINTE */
+#define SOF_DAI_INTEL_SSP_QUIRK_PINTE		(1 << 1)
+ /* ssc2: SMTATF */
+#define SOF_DAI_INTEL_SSP_QUIRK_SMTATF		(1 << 2)
+ /* ssc2: MMRATF */
+#define SOF_DAI_INTEL_SSP_QUIRK_MMRATF		(1 << 3)
+ /* ssc2: PSPSTWFDFD */
+#define SOF_DAI_INTEL_SSP_QUIRK_PSPSTWFDFD	(1 << 4)
+ /* ssc2: PSPSRWFDFD */
+#define SOF_DAI_INTEL_SSP_QUIRK_PSPSRWFDFD	(1 << 5)
+/* ssc1: LBM */
+#define SOF_DAI_INTEL_SSP_QUIRK_LBM		(1 << 6)
+
+ /* here is the possibility to define others aux macros */
+
+#define SOF_DAI_INTEL_SSP_FRAME_PULSE_WIDTH_MAX		38
+#define SOF_DAI_INTEL_SSP_SLOT_PADDING_MAX		31
+
+/* SSP clocks control settings
+ *
+ * Macros for clks_control field in sof_ipc_dai_ssp_params struct.
+ */
+
+/* mclk 0 disable */
+#define SOF_DAI_INTEL_SSP_MCLK_0_DISABLE		BIT(0)
+/* mclk 1 disable */
+#define SOF_DAI_INTEL_SSP_MCLK_1_DISABLE		BIT(1)
+/* mclk keep active */
+#define SOF_DAI_INTEL_SSP_CLKCTRL_MCLK_KA		BIT(2)
+/* bclk keep active */
+#define SOF_DAI_INTEL_SSP_CLKCTRL_BCLK_KA		BIT(3)
+/* fs keep active */
+#define SOF_DAI_INTEL_SSP_CLKCTRL_FS_KA			BIT(4)
+/* bclk idle */
+#define SOF_DAI_INTEL_SSP_CLKCTRL_BCLK_IDLE_HIGH	BIT(5)
+/* mclk early start */
+#define SOF_DAI_INTEL_SSP_CLKCTRL_MCLK_ES               BIT(6)
+/* bclk early start */
+#define SOF_DAI_INTEL_SSP_CLKCTRL_BCLK_ES               BIT(7)
+/* mclk always on */
+#define SOF_DAI_INTEL_SSP_CLKCTRL_MCLK_AON		BIT(8)
+
+/* DMIC max. four controllers for eight microphone channels */
+#define SOF_DAI_INTEL_DMIC_NUM_CTRL			4
+
+/* SSP Configuration Request - SOF_IPC_DAI_SSP_CONFIG */
+struct sof_ipc_dai_ssp_params {
+	struct sof_ipc_hdr hdr;
+	uint16_t reserved1;
+	uint16_t mclk_id;
+
+	uint32_t mclk_rate;	/* mclk frequency in Hz */
+	uint32_t fsync_rate;	/* fsync frequency in Hz */
+	uint32_t bclk_rate;	/* bclk frequency in Hz */
+
+	/* TDM */
+	uint32_t tdm_slots;
+	uint32_t rx_slots;
+	uint32_t tx_slots;
+
+	/* data */
+	uint32_t sample_valid_bits;
+	uint16_t tdm_slot_width;
+	uint16_t reserved2;	/* alignment */
+
+	/* MCLK */
+	uint32_t mclk_direction;
+
+	uint16_t frame_pulse_width;
+	uint16_t tdm_per_slot_padding_flag;
+	uint32_t clks_control;
+	uint32_t quirks;
+	uint32_t bclk_delay;	/* guaranteed time (ms) for which BCLK
+				 * will be driven, before sending data
+				 */
+} __packed;
+
+/* HDA Configuration Request - SOF_IPC_DAI_HDA_CONFIG */
+struct sof_ipc_dai_hda_params {
+	struct sof_ipc_hdr hdr;
+	uint32_t link_dma_ch;
+	uint32_t rate;
+	uint32_t channels;
+} __packed;
+
+/* ALH Configuration Request - SOF_IPC_DAI_ALH_CONFIG */
+struct sof_ipc_dai_alh_params {
+	struct sof_ipc_hdr hdr;
+	uint32_t stream_id;
+	uint32_t rate;
+	uint32_t channels;
+
+	/* reserved for future use */
+	uint32_t reserved[13];
+} __packed;
+
+/* DMIC Configuration Request - SOF_IPC_DAI_DMIC_CONFIG */
+
+/* This struct is defined per 2ch PDM controller available in the platform.
+ * Normally it is sufficient to set the used microphone specific enables to 1
+ * and keep other parameters as zero. The customizations are:
+ *
+ * 1. If a device mixes different microphones types with different polarity
+ * and/or the absolute polarity matters the PCM signal from a microphone
+ * can be inverted with the controls.
+ *
+ * 2. If the microphones in a stereo pair do not appear in captured stream
+ * in desired order due to board schematics choises they can be swapped with
+ * the clk_edge parameter.
+ *
+ * 3. If PDM bit errors are seen in capture (poor quality) the skew parameter
+ * that delays the sampling time of data by half cycles of DMIC source clock
+ * can be tried for improvement. However there is no guarantee for this to fix
+ * data integrity problems.
+ */
+struct sof_ipc_dai_dmic_pdm_ctrl {
+	struct sof_ipc_hdr hdr;
+	uint16_t id;		/**< PDM controller ID */
+
+	uint16_t enable_mic_a;	/**< Use A (left) channel mic (0 or 1)*/
+	uint16_t enable_mic_b;	/**< Use B (right) channel mic (0 or 1)*/
+
+	uint16_t polarity_mic_a; /**< Optionally invert mic A signal (0 or 1) */
+	uint16_t polarity_mic_b; /**< Optionally invert mic B signal (0 or 1) */
+
+	uint16_t clk_edge;	/**< Optionally swap data clock edge (0 or 1) */
+	uint16_t skew;		/**< Adjust PDM data sampling vs. clock (0..15) */
+
+	uint16_t reserved[3];	/**< Make sure the total size is 4 bytes aligned */
+} __packed;
+
+/* This struct contains the global settings for all 2ch PDM controllers. The
+ * version number used in configuration data is checked vs. version used by
+ * device driver src/drivers/dmic.c need to match. It is incremented from
+ * initial value 1 if updates done for the to driver would alter the operation
+ * of the microphone.
+ *
+ * Note: The microphone clock (pdmclk_min, pdmclk_max, duty_min, duty_max)
+ * parameters need to be set as defined in microphone data sheet. E.g. clock
+ * range 1.0 - 3.2 MHz is usually supported microphones. Some microphones are
+ * multi-mode capable and there may be denied mic clock frequencies between
+ * the modes. In such case set the clock range limits of the desired mode to
+ * avoid the driver to set clock to an illegal rate.
+ *
+ * The duty cycle could be set to 48-52% if not known. Generally these
+ * parameters can be altered within data sheet specified limits to match
+ * required audio application performance power.
+ *
+ * The microphone clock needs to be usually about 50-80 times the used audio
+ * sample rate. With highest sample rates above 48 kHz this can relaxed
+ * somewhat.
+ *
+ * The parameter wake_up_time describes how long time the microphone needs
+ * for the data line to produce valid output from mic clock start. The driver
+ * will mute the captured audio for the given time. The min_clock_on_time
+ * parameter is used to prevent too short clock bursts to happen. The driver
+ * will keep the clock active after capture stop if this time is not yet
+ * met. The unit for both is microseconds (us). Exceed of 100 ms will be
+ * treated as an error.
+ */
+struct sof_ipc_dai_dmic_params {
+	struct sof_ipc_hdr hdr;
+	uint32_t driver_ipc_version;	/**< Version (1..N) */
+
+	uint32_t pdmclk_min;	/**< Minimum microphone clock in Hz (100000..N) */
+	uint32_t pdmclk_max;	/**< Maximum microphone clock in Hz (min...N) */
+
+	uint32_t fifo_fs;	/**< FIFO sample rate in Hz (8000..96000) */
+	uint32_t reserved_1;	/**< Reserved */
+	uint16_t fifo_bits;	/**< FIFO word length (16 or 32) */
+	uint16_t fifo_bits_b;	/**< Deprecated since firmware ABI 3.0.1 */
+
+	uint16_t duty_min;	/**< Min. mic clock duty cycle in % (20..80) */
+	uint16_t duty_max;	/**< Max. mic clock duty cycle in % (min..80) */
+
+	uint32_t num_pdm_active; /**< Number of active pdm controllers. */
+				 /**< Range is 1..SOF_DAI_INTEL_DMIC_NUM_CTRL */
+
+	uint32_t wake_up_time;      /**< Time from clock start to data (us) */
+	uint32_t min_clock_on_time; /**< Min. time that clk is kept on (us) */
+	uint32_t unmute_ramp_time;  /**< Length of logarithmic gain ramp (ms) */
+
+	/* reserved for future use */
+	uint32_t reserved[5];
+
+	/**< PDM controllers configuration */
+	struct sof_ipc_dai_dmic_pdm_ctrl pdm[SOF_DAI_INTEL_DMIC_NUM_CTRL];
+} __packed;
+
+#endif