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/tcrypt.h | 99 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 99 insertions(+) create mode 100644 crypto/tcrypt.h (limited to 'crypto/tcrypt.h') diff --git a/crypto/tcrypt.h b/crypto/tcrypt.h new file mode 100644 index 000000000..85c3f77bc --- /dev/null +++ b/crypto/tcrypt.h @@ -0,0 +1,99 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Quick & dirty crypto benchmarking module. + * + * This will only exist until we have a better benchmarking mechanism + * (e.g. a char device). + * + * Copyright (c) 2002 James Morris + * Copyright (c) 2002 Jean-Francois Dive + * Copyright (c) 2007 Nokia Siemens Networks + */ +#ifndef _CRYPTO_TCRYPT_H +#define _CRYPTO_TCRYPT_H + +struct cipher_speed_template { + const char *key; + unsigned int klen; +}; + +struct aead_speed_template { + const char *key; + unsigned int klen; +}; + +struct hash_speed { + unsigned int blen; /* buffer length */ + unsigned int plen; /* per-update length */ +}; + +/* + * DES test vectors. + */ +#define DES3_SPEED_VECTORS 1 + +static struct cipher_speed_template des3_speed_template[] = { + { + .key = "\x01\x23\x45\x67\x89\xab\xcd\xef" + "\x55\x55\x55\x55\x55\x55\x55\x55" + "\xfe\xdc\xba\x98\x76\x54\x32\x10", + .klen = 24, + } +}; + +/* + * Cipher speed tests + */ +static u8 speed_template_8[] = {8, 0}; +static u8 speed_template_16[] = {16, 0}; +static u8 speed_template_24[] = {24, 0}; +static u8 speed_template_8_16[] = {8, 16, 0}; +static u8 speed_template_8_32[] = {8, 32, 0}; +static u8 speed_template_16_32[] = {16, 32, 0}; +static u8 speed_template_16_24_32[] = {16, 24, 32, 0}; +static u8 speed_template_20_28_36[] = {20, 28, 36, 0}; +static u8 speed_template_32_40_48[] = {32, 40, 48, 0}; +static u8 speed_template_32_48[] = {32, 48, 0}; +static u8 speed_template_32_48_64[] = {32, 48, 64, 0}; +static u8 speed_template_32_64[] = {32, 64, 0}; +static u8 speed_template_32[] = {32, 0}; + +/* + * AEAD speed tests + */ +static u8 aead_speed_template_19[] = {19, 0}; +static u8 aead_speed_template_20_28_36[] = {20, 28, 36, 0}; +static u8 aead_speed_template_36[] = {36, 0}; + +/* + * Digest speed tests + */ +static struct hash_speed generic_hash_speed_template[] = { + { .blen = 16, .plen = 16, }, + { .blen = 64, .plen = 16, }, + { .blen = 64, .plen = 64, }, + { .blen = 256, .plen = 16, }, + { .blen = 256, .plen = 64, }, + { .blen = 256, .plen = 256, }, + { .blen = 1024, .plen = 16, }, + { .blen = 1024, .plen = 256, }, + { .blen = 1024, .plen = 1024, }, + { .blen = 2048, .plen = 16, }, + { .blen = 2048, .plen = 256, }, + { .blen = 2048, .plen = 1024, }, + { .blen = 2048, .plen = 2048, }, + { .blen = 4096, .plen = 16, }, + { .blen = 4096, .plen = 256, }, + { .blen = 4096, .plen = 1024, }, + { .blen = 4096, .plen = 4096, }, + { .blen = 8192, .plen = 16, }, + { .blen = 8192, .plen = 256, }, + { .blen = 8192, .plen = 1024, }, + { .blen = 8192, .plen = 4096, }, + { .blen = 8192, .plen = 8192, }, + + /* End marker */ + { .blen = 0, .plen = 0, } +}; + +#endif /* _CRYPTO_TCRYPT_H */ -- cgit v1.3.1