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 --- crypto/sm3.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 89 insertions(+) create mode 100644 crypto/sm3.c (limited to 'crypto/sm3.c') diff --git a/crypto/sm3.c b/crypto/sm3.c new file mode 100644 index 000000000..05111a99b --- /dev/null +++ b/crypto/sm3.c @@ -0,0 +1,89 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * SM3 secure hash, as specified by OSCCA GM/T 0004-2012 SM3 and + * described at https://tools.ietf.org/html/draft-shen-sm3-hash-01 + * + * Copyright (C) 2017 ARM Limited or its affiliates. + * Written by Gilad Ben-Yossef + * Copyright (C) 2021 Tianjia Zhang + * Copyright 2026 Google LLC + */ + +#include +#include +#include +#include + +#define SM3_CTX(desc) ((struct sm3_ctx *)shash_desc_ctx(desc)) + +static int crypto_sm3_init(struct shash_desc *desc) +{ + sm3_init(SM3_CTX(desc)); + return 0; +} + +static int crypto_sm3_update(struct shash_desc *desc, + const u8 *data, unsigned int len) +{ + sm3_update(SM3_CTX(desc), data, len); + return 0; +} + +static int crypto_sm3_final(struct shash_desc *desc, u8 *out) +{ + sm3_final(SM3_CTX(desc), out); + return 0; +} + +static int crypto_sm3_digest(struct shash_desc *desc, + const u8 *data, unsigned int len, u8 *out) +{ + sm3(data, len, out); + return 0; +} + +static int crypto_sm3_export_core(struct shash_desc *desc, void *out) +{ + memcpy(out, SM3_CTX(desc), sizeof(struct sm3_ctx)); + return 0; +} + +static int crypto_sm3_import_core(struct shash_desc *desc, const void *in) +{ + memcpy(SM3_CTX(desc), in, sizeof(struct sm3_ctx)); + return 0; +} + +static struct shash_alg sm3_alg = { + .base.cra_name = "sm3", + .base.cra_driver_name = "sm3-lib", + .base.cra_priority = 300, + .base.cra_blocksize = SM3_BLOCK_SIZE, + .base.cra_module = THIS_MODULE, + .digestsize = SM3_DIGEST_SIZE, + .init = crypto_sm3_init, + .update = crypto_sm3_update, + .final = crypto_sm3_final, + .digest = crypto_sm3_digest, + .export_core = crypto_sm3_export_core, + .import_core = crypto_sm3_import_core, + .descsize = sizeof(struct sm3_ctx), +}; + +static int __init crypto_sm3_mod_init(void) +{ + return crypto_register_shash(&sm3_alg); +} +module_init(crypto_sm3_mod_init); + +static void __exit crypto_sm3_mod_exit(void) +{ + crypto_unregister_shash(&sm3_alg); +} +module_exit(crypto_sm3_mod_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Crypto API support for SM3"); + +MODULE_ALIAS_CRYPTO("sm3"); +MODULE_ALIAS_CRYPTO("sm3-lib"); -- cgit v1.3.1