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 --- net/tls/trace.h | 202 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 202 insertions(+) create mode 100644 net/tls/trace.h (limited to 'net/tls/trace.h') diff --git a/net/tls/trace.h b/net/tls/trace.h new file mode 100644 index 000000000..2d8ce4ff3 --- /dev/null +++ b/net/tls/trace.h @@ -0,0 +1,202 @@ +/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */ +/* Copyright (C) 2019 Netronome Systems, Inc. */ + +#undef TRACE_SYSTEM +#define TRACE_SYSTEM tls + +#if !defined(_TLS_TRACE_H_) || defined(TRACE_HEADER_MULTI_READ) +#define _TLS_TRACE_H_ + +#include +#include + +struct sock; + +TRACE_EVENT(tls_device_offload_set, + + TP_PROTO(struct sock *sk, int dir, u32 tcp_seq, u8 *rec_no, int ret), + + TP_ARGS(sk, dir, tcp_seq, rec_no, ret), + + TP_STRUCT__entry( + __field( struct sock *, sk ) + __field( u64, rec_no ) + __field( int, dir ) + __field( u32, tcp_seq ) + __field( int, ret ) + ), + + TP_fast_assign( + __entry->sk = sk; + __entry->rec_no = get_unaligned_be64(rec_no); + __entry->dir = dir; + __entry->tcp_seq = tcp_seq; + __entry->ret = ret; + ), + + TP_printk( + "sk=%p direction=%d tcp_seq=%u rec_no=%llu ret=%d", + __entry->sk, __entry->dir, __entry->tcp_seq, __entry->rec_no, + __entry->ret + ) +); + +TRACE_EVENT(tls_device_decrypted, + + TP_PROTO(struct sock *sk, u32 tcp_seq, u8 *rec_no, u32 rec_len, + bool encrypted, bool decrypted), + + TP_ARGS(sk, tcp_seq, rec_no, rec_len, encrypted, decrypted), + + TP_STRUCT__entry( + __field( struct sock *, sk ) + __field( u64, rec_no ) + __field( u32, tcp_seq ) + __field( u32, rec_len ) + __field( bool, encrypted ) + __field( bool, decrypted ) + ), + + TP_fast_assign( + __entry->sk = sk; + __entry->rec_no = get_unaligned_be64(rec_no); + __entry->tcp_seq = tcp_seq; + __entry->rec_len = rec_len; + __entry->encrypted = encrypted; + __entry->decrypted = decrypted; + ), + + TP_printk( + "sk=%p tcp_seq=%u rec_no=%llu len=%u encrypted=%d decrypted=%d", + __entry->sk, __entry->tcp_seq, + __entry->rec_no, __entry->rec_len, + __entry->encrypted, __entry->decrypted + ) +); + +TRACE_EVENT(tls_device_rx_resync_send, + + TP_PROTO(struct sock *sk, u32 tcp_seq, u8 *rec_no, int sync_type), + + TP_ARGS(sk, tcp_seq, rec_no, sync_type), + + TP_STRUCT__entry( + __field( struct sock *, sk ) + __field( u64, rec_no ) + __field( u32, tcp_seq ) + __field( int, sync_type ) + ), + + TP_fast_assign( + __entry->sk = sk; + __entry->rec_no = get_unaligned_be64(rec_no); + __entry->tcp_seq = tcp_seq; + __entry->sync_type = sync_type; + ), + + TP_printk( + "sk=%p tcp_seq=%u rec_no=%llu sync_type=%d", + __entry->sk, __entry->tcp_seq, __entry->rec_no, + __entry->sync_type + ) +); + +TRACE_EVENT(tls_device_rx_resync_nh_schedule, + + TP_PROTO(struct sock *sk), + + TP_ARGS(sk), + + TP_STRUCT__entry( + __field( struct sock *, sk ) + ), + + TP_fast_assign( + __entry->sk = sk; + ), + + TP_printk( + "sk=%p", __entry->sk + ) +); + +TRACE_EVENT(tls_device_rx_resync_nh_delay, + + TP_PROTO(struct sock *sk, u32 sock_data, u32 rec_len), + + TP_ARGS(sk, sock_data, rec_len), + + TP_STRUCT__entry( + __field( struct sock *, sk ) + __field( u32, sock_data ) + __field( u32, rec_len ) + ), + + TP_fast_assign( + __entry->sk = sk; + __entry->sock_data = sock_data; + __entry->rec_len = rec_len; + ), + + TP_printk( + "sk=%p sock_data=%u rec_len=%u", + __entry->sk, __entry->sock_data, __entry->rec_len + ) +); + +TRACE_EVENT(tls_device_tx_resync_req, + + TP_PROTO(struct sock *sk, u32 tcp_seq, u32 exp_tcp_seq), + + TP_ARGS(sk, tcp_seq, exp_tcp_seq), + + TP_STRUCT__entry( + __field( struct sock *, sk ) + __field( u32, tcp_seq ) + __field( u32, exp_tcp_seq ) + ), + + TP_fast_assign( + __entry->sk = sk; + __entry->tcp_seq = tcp_seq; + __entry->exp_tcp_seq = exp_tcp_seq; + ), + + TP_printk( + "sk=%p tcp_seq=%u exp_tcp_seq=%u", + __entry->sk, __entry->tcp_seq, __entry->exp_tcp_seq + ) +); + +TRACE_EVENT(tls_device_tx_resync_send, + + TP_PROTO(struct sock *sk, u32 tcp_seq, u8 *rec_no), + + TP_ARGS(sk, tcp_seq, rec_no), + + TP_STRUCT__entry( + __field( struct sock *, sk ) + __field( u64, rec_no ) + __field( u32, tcp_seq ) + ), + + TP_fast_assign( + __entry->sk = sk; + __entry->rec_no = get_unaligned_be64(rec_no); + __entry->tcp_seq = tcp_seq; + ), + + TP_printk( + "sk=%p tcp_seq=%u rec_no=%llu", + __entry->sk, __entry->tcp_seq, __entry->rec_no + ) +); + +#endif /* _TLS_TRACE_H_ */ + +#undef TRACE_INCLUDE_PATH +#define TRACE_INCLUDE_PATH . +#undef TRACE_INCLUDE_FILE +#define TRACE_INCLUDE_FILE trace + +#include -- cgit v1.3.1