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/carminefb.h | 65 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) create mode 100644 drivers/video/fbdev/carminefb.h (limited to 'drivers/video/fbdev/carminefb.h') diff --git a/drivers/video/fbdev/carminefb.h b/drivers/video/fbdev/carminefb.h new file mode 100644 index 000000000..c9825481d --- /dev/null +++ b/drivers/video/fbdev/carminefb.h @@ -0,0 +1,65 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef CARMINE_CARMINE_H +#define CARMINE_CARMINE_H + +#define CARMINE_MEMORY_BAR 2 +#define CARMINE_CONFIG_BAR 3 + +#define MAX_DISPLAY 2 +#define CARMINE_DISPLAY_MEM (800 * 600 * 4) +#define CARMINE_TOTAL_DISPLAY_MEM (CARMINE_DISPLAY_MEM * MAX_DISPLAY) + +#define CARMINE_USE_DISPLAY0 (1 << 0) +#define CARMINE_USE_DISPLAY1 (1 << 1) + +/* + * This values work on the eval card. Custom boards may use different timings, + * here an example :) + */ + +/* DRAM initialization values */ +#ifdef CONFIG_FB_CARMINE_DRAM_EVAL + +#define CARMINE_DFLT_IP_CLOCK_ENABLE (0x03ff) +#define CARMINE_DFLT_IP_DCTL_ADD (0x05c3) +#define CARMINE_DFLT_IP_DCTL_MODE (0x0121) +#define CARMINE_DFLT_IP_DCTL_EMODE (0x8000) +#define CARMINE_DFLT_IP_DCTL_SET_TIME1 (0x4749) +#define CARMINE_DFLT_IP_DCTL_SET_TIME2 (0x2a22) +#define CARMINE_DFLT_IP_DCTL_REFRESH (0x0042) +#define CARMINE_DFLT_IP_DCTL_STATES (0x0003) +#define CARMINE_DFLT_IP_DCTL_RESERVE0 (0x0020) +#define CARMINE_DFLT_IP_DCTL_FIFO_DEPTH (0x000f) +#define CARMINE_DFLT_IP_DCTL_RESERVE2 (0x0000) +#define CARMINE_DFLT_IP_DCTL_DDRIF1 (0x6646) +#define CARMINE_DFLT_IP_DCTL_DDRIF2 (0x0055) +#define CARMINE_DFLT_IP_DCTL_MODE_AFT_RST (0x0021) +#define CARMINE_DFLT_IP_DCTL_STATES_AFT_RST (0x0002) +#define CARMINE_DFLT_IP_DCTL_IO_CONT0 (0x0555) +#define CARMINE_DFLT_IP_DCTL_IO_CONT1 (0x0555) +#define CARMINE_DCTL_DLL_RESET (1) +#endif + +#ifdef CONFIG_CARMINE_DRAM_CUSTOM + +#define CARMINE_DFLT_IP_CLOCK_ENABLE (0x03ff) +#define CARMINE_DFLT_IP_DCTL_ADD (0x03b2) +#define CARMINE_DFLT_IP_DCTL_MODE (0x0161) +#define CARMINE_DFLT_IP_DCTL_EMODE (0x8000) +#define CARMINE_DFLT_IP_DCTL_SET_TIME1 (0x2628) +#define CARMINE_DFLT_IP_DCTL_SET_TIME2 (0x1a09) +#define CARMINE_DFLT_IP_DCTL_REFRESH (0x00fe) +#define CARMINE_DFLT_IP_DCTL_STATES (0x0003) +#define CARMINE_DFLT_IP_DCTL_RESERVE0 (0x0020) +#define CARMINE_DFLT_IP_DCTL_FIFO_DEPTH (0x000f) +#define CARMINE_DFLT_IP_DCTL_RESERVE2 (0x0000) +#define CARMINE_DFLT_IP_DCTL_DDRIF1 (0x0646) +#define CARMINE_DFLT_IP_DCTL_DDRIF2 (0x55aa) +#define CARMINE_DFLT_IP_DCTL_MODE_AFT_RST (0x0061) +#define CARMINE_DFLT_IP_DCTL_STATES_AFT_RST (0x0002) +#define CARMINE_DFLT_IP_DCTL_IO_CONT0 (0x0555) +#define CARMINE_DFLT_IP_DCTL_IO_CONT1 (0x0555) +#define CARMINE_DCTL_DLL_RESET (1) +#endif + +#endif -- cgit v1.3.1