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/crypto/bcm/util.h | 113 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 113 insertions(+) create mode 100644 drivers/crypto/bcm/util.h (limited to 'drivers/crypto/bcm/util.h') diff --git a/drivers/crypto/bcm/util.h b/drivers/crypto/bcm/util.h new file mode 100644 index 000000000..61c256384 --- /dev/null +++ b/drivers/crypto/bcm/util.h @@ -0,0 +1,113 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright 2016 Broadcom + */ + +#ifndef _UTIL_H +#define _UTIL_H + +#include +#include + +#include "spu.h" + +extern int flow_debug_logging; +extern int packet_debug_logging; +extern int debug_logging_sleep; + +#ifdef DEBUG +#define flow_log(...) \ + do { \ + if (flow_debug_logging) { \ + printk(__VA_ARGS__); \ + if (debug_logging_sleep) \ + msleep(debug_logging_sleep); \ + } \ + } while (0) +#define flow_dump(msg, var, var_len) \ + do { \ + if (flow_debug_logging) { \ + print_hex_dump(KERN_ALERT, msg, DUMP_PREFIX_NONE, \ + 16, 1, var, var_len, false); \ + if (debug_logging_sleep) \ + msleep(debug_logging_sleep); \ + } \ + } while (0) + +#define packet_log(...) \ + do { \ + if (packet_debug_logging) { \ + printk(__VA_ARGS__); \ + if (debug_logging_sleep) \ + msleep(debug_logging_sleep); \ + } \ + } while (0) +#define packet_dump(msg, var, var_len) \ + do { \ + if (packet_debug_logging) { \ + print_hex_dump(KERN_ALERT, msg, DUMP_PREFIX_NONE, \ + 16, 1, var, var_len, false); \ + if (debug_logging_sleep) \ + msleep(debug_logging_sleep); \ + } \ + } while (0) + +void __dump_sg(struct scatterlist *sg, unsigned int skip, unsigned int len); + +#define dump_sg(sg, skip, len) __dump_sg(sg, skip, len) + +#else /* !DEBUG_ON */ + +static inline void flow_log(const char *format, ...) +{ +} + +static inline void flow_dump(const char *msg, const void *var, size_t var_len) +{ +} + +static inline void packet_log(const char *format, ...) +{ +} + +static inline void packet_dump(const char *msg, const void *var, size_t var_len) +{ +} + +static inline void dump_sg(struct scatterlist *sg, unsigned int skip, + unsigned int len) +{ +} + +#endif /* DEBUG_ON */ + +int spu_sg_at_offset(struct scatterlist *sg, unsigned int skip, + struct scatterlist **sge, unsigned int *sge_offset); + +/* Copy sg data, from skip, length len, to dest */ +void sg_copy_part_to_buf(struct scatterlist *src, u8 *dest, + unsigned int len, unsigned int skip); +/* Copy src into scatterlist from offset, length len */ +void sg_copy_part_from_buf(struct scatterlist *dest, u8 *src, + unsigned int len, unsigned int skip); + +int spu_sg_count(struct scatterlist *sg_list, unsigned int skip, int nbytes); +u32 spu_msg_sg_add(struct scatterlist **to_sg, + struct scatterlist **from_sg, u32 *skip, + u8 from_nents, u32 tot_len); + +void add_to_ctr(u8 *ctr_pos, unsigned int increment); + +/* produce a message digest from data of length n bytes */ +int do_shash(unsigned char *name, unsigned char *result, + const u8 *data1, unsigned int data1_len, + const u8 *data2, unsigned int data2_len, + const u8 *key, unsigned int key_len); + +char *spu_alg_name(enum spu_cipher_alg alg, enum spu_cipher_mode mode); + +void spu_setup_debugfs(void); +void spu_free_debugfs(void); +void format_value_ccm(unsigned int val, u8 *buf, u8 len); + +#endif -- cgit v1.3.1