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/dsa/trace.h | 447 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 447 insertions(+) create mode 100644 net/dsa/trace.h (limited to 'net/dsa/trace.h') diff --git a/net/dsa/trace.h b/net/dsa/trace.h new file mode 100644 index 000000000..83f3e5f78 --- /dev/null +++ b/net/dsa/trace.h @@ -0,0 +1,447 @@ +/* SPDX-License-Identifier: GPL-2.0 + * Copyright 2022-2023 NXP + */ + +#undef TRACE_SYSTEM +#define TRACE_SYSTEM dsa + +#if !defined(_NET_DSA_TRACE_H) || defined(TRACE_HEADER_MULTI_READ) +#define _NET_DSA_TRACE_H + +#include +#include +#include +#include +#include +#include + +/* Enough to fit "bridge %s num %d" where num has 3 digits */ +#define DSA_DB_BUFSIZ (IFNAMSIZ + 16) + +void dsa_db_print(const struct dsa_db *db, char buf[DSA_DB_BUFSIZ]); +const char *dsa_port_kind(const struct dsa_port *dp); + +DECLARE_EVENT_CLASS(dsa_port_addr_op_hw, + + TP_PROTO(const struct dsa_port *dp, const unsigned char *addr, u16 vid, + const struct dsa_db *db, int err), + + TP_ARGS(dp, addr, vid, db, err), + + TP_STRUCT__entry( + __string(dev, dev_name(dp->ds->dev)) + __string(kind, dsa_port_kind(dp)) + __field(int, port) + __array(unsigned char, addr, ETH_ALEN) + __field(u16, vid) + __array(char, db_buf, DSA_DB_BUFSIZ) + __field(int, err) + ), + + TP_fast_assign( + __assign_str(dev); + __assign_str(kind); + __entry->port = dp->index; + ether_addr_copy(__entry->addr, addr); + __entry->vid = vid; + dsa_db_print(db, __entry->db_buf); + __entry->err = err; + ), + + TP_printk("%s %s port %d addr %pM vid %u db \"%s\" err %d", + __get_str(dev), __get_str(kind), __entry->port, __entry->addr, + __entry->vid, __entry->db_buf, __entry->err) +); + +/* Add unicast/multicast address to hardware, either on user ports + * (where no refcounting is kept), or on shared ports when the entry + * is first seen and its refcount is 1. + */ +DEFINE_EVENT(dsa_port_addr_op_hw, dsa_fdb_add_hw, + TP_PROTO(const struct dsa_port *dp, const unsigned char *addr, + u16 vid, const struct dsa_db *db, int err), + TP_ARGS(dp, addr, vid, db, err)); + +DEFINE_EVENT(dsa_port_addr_op_hw, dsa_mdb_add_hw, + TP_PROTO(const struct dsa_port *dp, const unsigned char *addr, + u16 vid, const struct dsa_db *db, int err), + TP_ARGS(dp, addr, vid, db, err)); + +/* Delete unicast/multicast address from hardware, either on user ports or + * when the refcount on shared ports reaches 0 + */ +DEFINE_EVENT(dsa_port_addr_op_hw, dsa_fdb_del_hw, + TP_PROTO(const struct dsa_port *dp, const unsigned char *addr, + u16 vid, const struct dsa_db *db, int err), + TP_ARGS(dp, addr, vid, db, err)); + +DEFINE_EVENT(dsa_port_addr_op_hw, dsa_mdb_del_hw, + TP_PROTO(const struct dsa_port *dp, const unsigned char *addr, + u16 vid, const struct dsa_db *db, int err), + TP_ARGS(dp, addr, vid, db, err)); + +DECLARE_EVENT_CLASS(dsa_port_addr_op_refcount, + + TP_PROTO(const struct dsa_port *dp, const unsigned char *addr, u16 vid, + const struct dsa_db *db, const refcount_t *refcount), + + TP_ARGS(dp, addr, vid, db, refcount), + + TP_STRUCT__entry( + __string(dev, dev_name(dp->ds->dev)) + __string(kind, dsa_port_kind(dp)) + __field(int, port) + __array(unsigned char, addr, ETH_ALEN) + __field(u16, vid) + __array(char, db_buf, DSA_DB_BUFSIZ) + __field(unsigned int, refcount) + ), + + TP_fast_assign( + __assign_str(dev); + __assign_str(kind); + __entry->port = dp->index; + ether_addr_copy(__entry->addr, addr); + __entry->vid = vid; + dsa_db_print(db, __entry->db_buf); + __entry->refcount = refcount_read(refcount); + ), + + TP_printk("%s %s port %d addr %pM vid %u db \"%s\" refcount %u", + __get_str(dev), __get_str(kind), __entry->port, __entry->addr, + __entry->vid, __entry->db_buf, __entry->refcount) +); + +/* Bump the refcount of an existing unicast/multicast address on shared ports */ +DEFINE_EVENT(dsa_port_addr_op_refcount, dsa_fdb_add_bump, + TP_PROTO(const struct dsa_port *dp, const unsigned char *addr, + u16 vid, const struct dsa_db *db, + const refcount_t *refcount), + TP_ARGS(dp, addr, vid, db, refcount)); + +DEFINE_EVENT(dsa_port_addr_op_refcount, dsa_mdb_add_bump, + TP_PROTO(const struct dsa_port *dp, const unsigned char *addr, + u16 vid, const struct dsa_db *db, + const refcount_t *refcount), + TP_ARGS(dp, addr, vid, db, refcount)); + +/* Drop the refcount of a multicast address that we still keep on + * shared ports + */ +DEFINE_EVENT(dsa_port_addr_op_refcount, dsa_fdb_del_drop, + TP_PROTO(const struct dsa_port *dp, const unsigned char *addr, + u16 vid, const struct dsa_db *db, + const refcount_t *refcount), + TP_ARGS(dp, addr, vid, db, refcount)); + +DEFINE_EVENT(dsa_port_addr_op_refcount, dsa_mdb_del_drop, + TP_PROTO(const struct dsa_port *dp, const unsigned char *addr, + u16 vid, const struct dsa_db *db, + const refcount_t *refcount), + TP_ARGS(dp, addr, vid, db, refcount)); + +DECLARE_EVENT_CLASS(dsa_port_addr_del_not_found, + + TP_PROTO(const struct dsa_port *dp, const unsigned char *addr, u16 vid, + const struct dsa_db *db), + + TP_ARGS(dp, addr, vid, db), + + TP_STRUCT__entry( + __string(dev, dev_name(dp->ds->dev)) + __string(kind, dsa_port_kind(dp)) + __field(int, port) + __array(unsigned char, addr, ETH_ALEN) + __field(u16, vid) + __array(char, db_buf, DSA_DB_BUFSIZ) + ), + + TP_fast_assign( + __assign_str(dev); + __assign_str(kind); + __entry->port = dp->index; + ether_addr_copy(__entry->addr, addr); + __entry->vid = vid; + dsa_db_print(db, __entry->db_buf); + ), + + TP_printk("%s %s port %d addr %pM vid %u db \"%s\"", + __get_str(dev), __get_str(kind), __entry->port, + __entry->addr, __entry->vid, __entry->db_buf) +); + +/* Attempt to delete a unicast/multicast address on shared ports for which + * the delete operation was called more times than the addition + */ +DEFINE_EVENT(dsa_port_addr_del_not_found, dsa_fdb_del_not_found, + TP_PROTO(const struct dsa_port *dp, const unsigned char *addr, + u16 vid, const struct dsa_db *db), + TP_ARGS(dp, addr, vid, db)); + +DEFINE_EVENT(dsa_port_addr_del_not_found, dsa_mdb_del_not_found, + TP_PROTO(const struct dsa_port *dp, const unsigned char *addr, + u16 vid, const struct dsa_db *db), + TP_ARGS(dp, addr, vid, db)); + +TRACE_EVENT(dsa_lag_fdb_add_hw, + + TP_PROTO(const struct net_device *lag_dev, const unsigned char *addr, + u16 vid, const struct dsa_db *db, int err), + + TP_ARGS(lag_dev, addr, vid, db, err), + + TP_STRUCT__entry( + __string(dev, lag_dev->name) + __array(unsigned char, addr, ETH_ALEN) + __field(u16, vid) + __array(char, db_buf, DSA_DB_BUFSIZ) + __field(int, err) + ), + + TP_fast_assign( + __assign_str(dev); + ether_addr_copy(__entry->addr, addr); + __entry->vid = vid; + dsa_db_print(db, __entry->db_buf); + __entry->err = err; + ), + + TP_printk("%s addr %pM vid %u db \"%s\" err %d", + __get_str(dev), __entry->addr, __entry->vid, + __entry->db_buf, __entry->err) +); + +TRACE_EVENT(dsa_lag_fdb_add_bump, + + TP_PROTO(const struct net_device *lag_dev, const unsigned char *addr, + u16 vid, const struct dsa_db *db, const refcount_t *refcount), + + TP_ARGS(lag_dev, addr, vid, db, refcount), + + TP_STRUCT__entry( + __string(dev, lag_dev->name) + __array(unsigned char, addr, ETH_ALEN) + __field(u16, vid) + __array(char, db_buf, DSA_DB_BUFSIZ) + __field(unsigned int, refcount) + ), + + TP_fast_assign( + __assign_str(dev); + ether_addr_copy(__entry->addr, addr); + __entry->vid = vid; + dsa_db_print(db, __entry->db_buf); + __entry->refcount = refcount_read(refcount); + ), + + TP_printk("%s addr %pM vid %u db \"%s\" refcount %u", + __get_str(dev), __entry->addr, __entry->vid, + __entry->db_buf, __entry->refcount) +); + +TRACE_EVENT(dsa_lag_fdb_del_hw, + + TP_PROTO(const struct net_device *lag_dev, const unsigned char *addr, + u16 vid, const struct dsa_db *db, int err), + + TP_ARGS(lag_dev, addr, vid, db, err), + + TP_STRUCT__entry( + __string(dev, lag_dev->name) + __array(unsigned char, addr, ETH_ALEN) + __field(u16, vid) + __array(char, db_buf, DSA_DB_BUFSIZ) + __field(int, err) + ), + + TP_fast_assign( + __assign_str(dev); + ether_addr_copy(__entry->addr, addr); + __entry->vid = vid; + dsa_db_print(db, __entry->db_buf); + __entry->err = err; + ), + + TP_printk("%s addr %pM vid %u db \"%s\" err %d", + __get_str(dev), __entry->addr, __entry->vid, + __entry->db_buf, __entry->err) +); + +TRACE_EVENT(dsa_lag_fdb_del_drop, + + TP_PROTO(const struct net_device *lag_dev, const unsigned char *addr, + u16 vid, const struct dsa_db *db, const refcount_t *refcount), + + TP_ARGS(lag_dev, addr, vid, db, refcount), + + TP_STRUCT__entry( + __string(dev, lag_dev->name) + __array(unsigned char, addr, ETH_ALEN) + __field(u16, vid) + __array(char, db_buf, DSA_DB_BUFSIZ) + __field(unsigned int, refcount) + ), + + TP_fast_assign( + __assign_str(dev); + ether_addr_copy(__entry->addr, addr); + __entry->vid = vid; + dsa_db_print(db, __entry->db_buf); + __entry->refcount = refcount_read(refcount); + ), + + TP_printk("%s addr %pM vid %u db \"%s\" refcount %u", + __get_str(dev), __entry->addr, __entry->vid, + __entry->db_buf, __entry->refcount) +); + +TRACE_EVENT(dsa_lag_fdb_del_not_found, + + TP_PROTO(const struct net_device *lag_dev, const unsigned char *addr, + u16 vid, const struct dsa_db *db), + + TP_ARGS(lag_dev, addr, vid, db), + + TP_STRUCT__entry( + __string(dev, lag_dev->name) + __array(unsigned char, addr, ETH_ALEN) + __field(u16, vid) + __array(char, db_buf, DSA_DB_BUFSIZ) + ), + + TP_fast_assign( + __assign_str(dev); + ether_addr_copy(__entry->addr, addr); + __entry->vid = vid; + dsa_db_print(db, __entry->db_buf); + ), + + TP_printk("%s addr %pM vid %u db \"%s\"", + __get_str(dev), __entry->addr, __entry->vid, __entry->db_buf) +); + +DECLARE_EVENT_CLASS(dsa_vlan_op_hw, + + TP_PROTO(const struct dsa_port *dp, + const struct switchdev_obj_port_vlan *vlan, int err), + + TP_ARGS(dp, vlan, err), + + TP_STRUCT__entry( + __string(dev, dev_name(dp->ds->dev)) + __string(kind, dsa_port_kind(dp)) + __field(int, port) + __field(u16, vid) + __field(u16, flags) + __field(bool, changed) + __field(int, err) + ), + + TP_fast_assign( + __assign_str(dev); + __assign_str(kind); + __entry->port = dp->index; + __entry->vid = vlan->vid; + __entry->flags = vlan->flags; + __entry->changed = vlan->changed; + __entry->err = err; + ), + + TP_printk("%s %s port %d vid %u%s%s%s", + __get_str(dev), __get_str(kind), __entry->port, __entry->vid, + __entry->flags & BRIDGE_VLAN_INFO_PVID ? " pvid" : "", + __entry->flags & BRIDGE_VLAN_INFO_UNTAGGED ? " untagged" : "", + __entry->changed ? " (changed)" : "") +); + +DEFINE_EVENT(dsa_vlan_op_hw, dsa_vlan_add_hw, + TP_PROTO(const struct dsa_port *dp, + const struct switchdev_obj_port_vlan *vlan, int err), + TP_ARGS(dp, vlan, err)); + +DEFINE_EVENT(dsa_vlan_op_hw, dsa_vlan_del_hw, + TP_PROTO(const struct dsa_port *dp, + const struct switchdev_obj_port_vlan *vlan, int err), + TP_ARGS(dp, vlan, err)); + +DECLARE_EVENT_CLASS(dsa_vlan_op_refcount, + + TP_PROTO(const struct dsa_port *dp, + const struct switchdev_obj_port_vlan *vlan, + const refcount_t *refcount), + + TP_ARGS(dp, vlan, refcount), + + TP_STRUCT__entry( + __string(dev, dev_name(dp->ds->dev)) + __string(kind, dsa_port_kind(dp)) + __field(int, port) + __field(u16, vid) + __field(u16, flags) + __field(bool, changed) + __field(unsigned int, refcount) + ), + + TP_fast_assign( + __assign_str(dev); + __assign_str(kind); + __entry->port = dp->index; + __entry->vid = vlan->vid; + __entry->flags = vlan->flags; + __entry->changed = vlan->changed; + __entry->refcount = refcount_read(refcount); + ), + + TP_printk("%s %s port %d vid %u%s%s%s refcount %u", + __get_str(dev), __get_str(kind), __entry->port, __entry->vid, + __entry->flags & BRIDGE_VLAN_INFO_PVID ? " pvid" : "", + __entry->flags & BRIDGE_VLAN_INFO_UNTAGGED ? " untagged" : "", + __entry->changed ? " (changed)" : "", __entry->refcount) +); + +DEFINE_EVENT(dsa_vlan_op_refcount, dsa_vlan_add_bump, + TP_PROTO(const struct dsa_port *dp, + const struct switchdev_obj_port_vlan *vlan, + const refcount_t *refcount), + TP_ARGS(dp, vlan, refcount)); + +DEFINE_EVENT(dsa_vlan_op_refcount, dsa_vlan_del_drop, + TP_PROTO(const struct dsa_port *dp, + const struct switchdev_obj_port_vlan *vlan, + const refcount_t *refcount), + TP_ARGS(dp, vlan, refcount)); + +TRACE_EVENT(dsa_vlan_del_not_found, + + TP_PROTO(const struct dsa_port *dp, + const struct switchdev_obj_port_vlan *vlan), + + TP_ARGS(dp, vlan), + + TP_STRUCT__entry( + __string(dev, dev_name(dp->ds->dev)) + __string(kind, dsa_port_kind(dp)) + __field(int, port) + __field(u16, vid) + ), + + TP_fast_assign( + __assign_str(dev); + __assign_str(kind); + __entry->port = dp->index; + __entry->vid = vlan->vid; + ), + + TP_printk("%s %s port %d vid %u", + __get_str(dev), __get_str(kind), __entry->port, __entry->vid) +); + +#endif /* _NET_DSA_TRACE_H */ + +/* We don't want to use include/trace/events */ +#undef TRACE_INCLUDE_PATH +#define TRACE_INCLUDE_PATH . +#undef TRACE_INCLUDE_FILE +#define TRACE_INCLUDE_FILE trace +/* This part must be outside protection */ +#include -- cgit v1.3.1