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/qce/cipher.h | 56 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) create mode 100644 drivers/crypto/qce/cipher.h (limited to 'drivers/crypto/qce/cipher.h') diff --git a/drivers/crypto/qce/cipher.h b/drivers/crypto/qce/cipher.h new file mode 100644 index 000000000..850f257d0 --- /dev/null +++ b/drivers/crypto/qce/cipher.h @@ -0,0 +1,56 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (c) 2010-2014, The Linux Foundation. All rights reserved. + */ + +#ifndef _CIPHER_H_ +#define _CIPHER_H_ + +#include "common.h" +#include "core.h" + +#define QCE_MAX_KEY_SIZE 64 + +struct qce_cipher_ctx { + u8 enc_key[QCE_MAX_KEY_SIZE]; + unsigned int enc_keylen; + struct crypto_skcipher *fallback; +}; + +/** + * struct qce_cipher_reqctx - holds private cipher objects per request + * @flags: operation flags + * @iv: pointer to the IV + * @ivsize: IV size + * @src_nents: source entries + * @dst_nents: destination entries + * @result_sg: scatterlist used for result buffer + * @dst_tbl: destination sg table + * @dst_sg: destination sg pointer table beginning + * @src_tbl: source sg table + * @src_sg: source sg pointer table beginning; + * @cryptlen: crypto length + */ +struct qce_cipher_reqctx { + unsigned long flags; + u8 *iv; + unsigned int ivsize; + int src_nents; + int dst_nents; + struct scatterlist result_sg; + struct sg_table dst_tbl; + struct scatterlist *dst_sg; + struct scatterlist *src_sg; + unsigned int cryptlen; + struct skcipher_request fallback_req; // keep at the end +}; + +static inline struct qce_alg_template *to_cipher_tmpl(struct crypto_skcipher *tfm) +{ + struct skcipher_alg *alg = crypto_skcipher_alg(tfm); + return container_of(alg, struct qce_alg_template, alg.skcipher); +} + +extern const struct qce_algo_ops skcipher_ops; + +#endif /* _CIPHER_H_ */ -- cgit v1.3.1