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 --- arch/powerpc/boot/ppcboot.h | 95 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 95 insertions(+) create mode 100644 arch/powerpc/boot/ppcboot.h (limited to 'arch/powerpc/boot/ppcboot.h') diff --git a/arch/powerpc/boot/ppcboot.h b/arch/powerpc/boot/ppcboot.h new file mode 100644 index 000000000..90c8f452f --- /dev/null +++ b/arch/powerpc/boot/ppcboot.h @@ -0,0 +1,95 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * This interface is used for compatibility with old U-boots *ONLY*. + * Please do not imitate or extend this. + */ + +/* + * (C) Copyright 2000, 2001 + * Wolfgang Denk, DENX Software Engineering, wd@denx.de. + */ + +#ifndef __PPCBOOT_H__ +#define __PPCBOOT_H__ + +/* + * Board information passed to kernel from PPCBoot + * + * include/asm-ppc/ppcboot.h + */ + +#include "types.h" + +typedef struct bd_info { + unsigned long bi_memstart; /* start of DRAM memory */ + unsigned long bi_memsize; /* size of DRAM memory in bytes */ + unsigned long bi_flashstart; /* start of FLASH memory */ + unsigned long bi_flashsize; /* size of FLASH memory */ + unsigned long bi_flashoffset; /* reserved area for startup monitor */ + unsigned long bi_sramstart; /* start of SRAM memory */ + unsigned long bi_sramsize; /* size of SRAM memory */ +#if defined(TARGET_8xx) || defined(TARGET_CPM2) || defined(TARGET_85xx) ||\ + defined(TARGET_83xx) || defined(TARGET_86xx) + unsigned long bi_immr_base; /* base of IMMR register */ +#endif +#if defined(TARGET_PPC_MPC52xx) + unsigned long bi_mbar_base; /* base of internal registers */ +#endif + unsigned long bi_bootflags; /* boot / reboot flag (for LynxOS) */ + unsigned long bi_ip_addr; /* IP Address */ + unsigned char bi_enetaddr[6]; /* Ethernet address */ + unsigned short bi_ethspeed; /* Ethernet speed in Mbps */ + unsigned long bi_intfreq; /* Internal Freq, in MHz */ + unsigned long bi_busfreq; /* Bus Freq, in MHz */ +#if defined(TARGET_CPM2) + unsigned long bi_cpmfreq; /* CPM_CLK Freq, in MHz */ + unsigned long bi_brgfreq; /* BRG_CLK Freq, in MHz */ + unsigned long bi_sccfreq; /* SCC_CLK Freq, in MHz */ + unsigned long bi_vco; /* VCO Out from PLL, in MHz */ +#endif +#if defined(TARGET_PPC_MPC52xx) + unsigned long bi_ipbfreq; /* IPB Bus Freq, in MHz */ + unsigned long bi_pcifreq; /* PCI Bus Freq, in MHz */ +#endif + unsigned long bi_baudrate; /* Console Baudrate */ +#if defined(TARGET_4xx) + unsigned char bi_s_version[4]; /* Version of this structure */ + unsigned char bi_r_version[32]; /* Version of the ROM (IBM) */ + unsigned int bi_procfreq; /* CPU (Internal) Freq, in Hz */ + unsigned int bi_plb_busfreq; /* PLB Bus speed, in Hz */ + unsigned int bi_pci_busfreq; /* PCI Bus speed, in Hz */ + unsigned char bi_pci_enetaddr[6]; /* PCI Ethernet MAC address */ +#endif +#if defined(TARGET_HYMOD) + hymod_conf_t bi_hymod_conf; /* hymod configuration information */ +#endif +#if defined(TARGET_EVB64260) || defined(TARGET_44x) || \ + defined(TARGET_85xx) || defined(TARGET_83xx) || defined(TARGET_HAS_ETH1) + /* second onboard ethernet port */ + unsigned char bi_enet1addr[6]; +#define HAVE_ENET1ADDR +#endif +#if defined(TARGET_EVB64260) || defined(TARGET_440GX) || \ + defined(TARGET_85xx) || defined(TARGET_HAS_ETH2) + /* third onboard ethernet ports */ + unsigned char bi_enet2addr[6]; +#define HAVE_ENET2ADDR +#endif +#if defined(TARGET_440GX) || defined(TARGET_HAS_ETH3) + /* fourth onboard ethernet ports */ + unsigned char bi_enet3addr[6]; +#define HAVE_ENET3ADDR +#endif +#if defined(TARGET_4xx) + unsigned int bi_opbfreq; /* OB clock in Hz */ + int bi_iic_fast[2]; /* Use fast i2c mode */ +#endif +#if defined(TARGET_440GX) + int bi_phynum[4]; /* phy mapping */ + int bi_phymode[4]; /* phy mode */ +#endif +} bd_t; + +#define bi_tbfreq bi_intfreq + +#endif /* __PPCBOOT_H__ */ -- cgit v1.3.1