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/video/fbdev/edid.h | 138 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 138 insertions(+) create mode 100644 drivers/video/fbdev/edid.h (limited to 'drivers/video/fbdev/edid.h') diff --git a/drivers/video/fbdev/edid.h b/drivers/video/fbdev/edid.h new file mode 100644 index 000000000..d03a232d9 --- /dev/null +++ b/drivers/video/fbdev/edid.h @@ -0,0 +1,138 @@ +/* + * drivers/video/edid.h - EDID/DDC Header + * + * Based on: + * 1. XFree86 4.3.0, edid.h + * Copyright 1998 by Egbert Eich + * + * 2. John Fremlin and + * Ani Joshi + * + * DDC is a Trademark of VESA (Video Electronics Standard Association). + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file COPYING in the main directory of this archive + * for more details. +*/ + +#ifndef __EDID_H__ +#define __EDID_H__ + +#define EDID_LENGTH 0x80 +#define EDID_HEADER 0x00 +#define EDID_HEADER_END 0x07 + +#define ID_MANUFACTURER_NAME 0x08 +#define ID_MANUFACTURER_NAME_END 0x09 +#define ID_MODEL 0x0a + +#define ID_SERIAL_NUMBER 0x0c + +#define MANUFACTURE_WEEK 0x10 +#define MANUFACTURE_YEAR 0x11 + +#define EDID_STRUCT_VERSION 0x12 +#define EDID_STRUCT_REVISION 0x13 + +#define EDID_STRUCT_DISPLAY 0x14 + +#define DPMS_FLAGS 0x18 +#define ESTABLISHED_TIMING_1 0x23 +#define ESTABLISHED_TIMING_2 0x24 +#define MANUFACTURERS_TIMINGS 0x25 + +/* standard timings supported */ +#define STD_TIMING 8 +#define STD_TIMING_DESCRIPTION_SIZE 2 +#define STD_TIMING_DESCRIPTIONS_START 0x26 + +#define DETAILED_TIMING_DESCRIPTIONS_START 0x36 +#define DETAILED_TIMING_DESCRIPTION_SIZE 18 +#define NO_DETAILED_TIMING_DESCRIPTIONS 4 + +#define DETAILED_TIMING_DESCRIPTION_1 0x36 +#define DETAILED_TIMING_DESCRIPTION_2 0x48 +#define DETAILED_TIMING_DESCRIPTION_3 0x5a +#define DETAILED_TIMING_DESCRIPTION_4 0x6c + +#define DESCRIPTOR_DATA 5 + +#define UPPER_NIBBLE( x ) \ + (((128|64|32|16) & (x)) >> 4) + +#define LOWER_NIBBLE( x ) \ + ((1|2|4|8) & (x)) + +#define COMBINE_HI_8LO( hi, lo ) \ + ( (((unsigned)hi) << 8) | (unsigned)lo ) + +#define COMBINE_HI_4LO( hi, lo ) \ + ( (((unsigned)hi) << 4) | (unsigned)lo ) + +#define PIXEL_CLOCK_LO (unsigned)block[ 0 ] +#define PIXEL_CLOCK_HI (unsigned)block[ 1 ] +#define PIXEL_CLOCK (COMBINE_HI_8LO( PIXEL_CLOCK_HI,PIXEL_CLOCK_LO )*10000) +#define H_ACTIVE_LO (unsigned)block[ 2 ] +#define H_BLANKING_LO (unsigned)block[ 3 ] +#define H_ACTIVE_HI UPPER_NIBBLE( (unsigned)block[ 4 ] ) +#define H_ACTIVE COMBINE_HI_8LO( H_ACTIVE_HI, H_ACTIVE_LO ) +#define H_BLANKING_HI LOWER_NIBBLE( (unsigned)block[ 4 ] ) +#define H_BLANKING COMBINE_HI_8LO( H_BLANKING_HI, H_BLANKING_LO ) + +#define V_ACTIVE_LO (unsigned)block[ 5 ] +#define V_BLANKING_LO (unsigned)block[ 6 ] +#define V_ACTIVE_HI UPPER_NIBBLE( (unsigned)block[ 7 ] ) +#define V_ACTIVE COMBINE_HI_8LO( V_ACTIVE_HI, V_ACTIVE_LO ) +#define V_BLANKING_HI LOWER_NIBBLE( (unsigned)block[ 7 ] ) +#define V_BLANKING COMBINE_HI_8LO( V_BLANKING_HI, V_BLANKING_LO ) + +#define H_SYNC_OFFSET_LO (unsigned)block[ 8 ] +#define H_SYNC_WIDTH_LO (unsigned)block[ 9 ] + +#define V_SYNC_OFFSET_LO UPPER_NIBBLE( (unsigned)block[ 10 ] ) +#define V_SYNC_WIDTH_LO LOWER_NIBBLE( (unsigned)block[ 10 ] ) + +#define V_SYNC_WIDTH_HI ((unsigned)block[ 11 ] & (1|2)) +#define V_SYNC_OFFSET_HI (((unsigned)block[ 11 ] & (4|8)) >> 2) + +#define H_SYNC_WIDTH_HI (((unsigned)block[ 11 ] & (16|32)) >> 4) +#define H_SYNC_OFFSET_HI (((unsigned)block[ 11 ] & (64|128)) >> 6) + +#define V_SYNC_WIDTH COMBINE_HI_4LO( V_SYNC_WIDTH_HI, V_SYNC_WIDTH_LO ) +#define V_SYNC_OFFSET COMBINE_HI_4LO( V_SYNC_OFFSET_HI, V_SYNC_OFFSET_LO ) + +#define H_SYNC_WIDTH COMBINE_HI_8LO( H_SYNC_WIDTH_HI, H_SYNC_WIDTH_LO ) +#define H_SYNC_OFFSET COMBINE_HI_8LO( H_SYNC_OFFSET_HI, H_SYNC_OFFSET_LO ) + +#define H_SIZE_LO (unsigned)block[ 12 ] +#define V_SIZE_LO (unsigned)block[ 13 ] + +#define H_SIZE_HI UPPER_NIBBLE( (unsigned)block[ 14 ] ) +#define V_SIZE_HI LOWER_NIBBLE( (unsigned)block[ 14 ] ) + +#define H_SIZE COMBINE_HI_8LO( H_SIZE_HI, H_SIZE_LO ) +#define V_SIZE COMBINE_HI_8LO( V_SIZE_HI, V_SIZE_LO ) + +#define H_BORDER (unsigned)block[ 15 ] +#define V_BORDER (unsigned)block[ 16 ] + +#define FLAGS (unsigned)block[ 17 ] + +#define INTERLACED (FLAGS&128) +#define SYNC_TYPE (FLAGS&3<<3) /* bits 4,3 */ +#define SYNC_SEPARATE (3<<3) +#define HSYNC_POSITIVE (FLAGS & 4) +#define VSYNC_POSITIVE (FLAGS & 2) + +#define V_MIN_RATE block[ 5 ] +#define V_MAX_RATE block[ 6 ] +#define H_MIN_RATE block[ 7 ] +#define H_MAX_RATE block[ 8 ] +#define MAX_PIXEL_CLOCK (((int)block[ 9 ]) * 10) +#define GTF_SUPPORT block[10] + +#define DPMS_ACTIVE_OFF (1 << 5) +#define DPMS_SUSPEND (1 << 6) +#define DPMS_STANDBY (1 << 7) + +#endif /* __EDID_H__ */ -- cgit v1.3.1