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* perf lock contention: Add -G/--cgroup-filter optionNamhyung Kim2023-09-121-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The -G/--cgroup-filter is to limit lock contention collection on the tasks in the specific cgroups only. $ sudo ./perf lock con -abt -G /user.slice/.../vte-spawn-52221fb8-b33f-4a52-b5c3-e35d1e6fc0e0.scope \ ./perf bench sched messaging # Running 'sched/messaging' benchmark: # 20 sender and receiver processes per group # 10 groups == 400 processes run Total time: 0.174 [sec] contended total wait max wait avg wait pid comm 4 114.45 us 60.06 us 28.61 us 214847 sched-messaging 2 111.40 us 60.84 us 55.70 us 214848 sched-messaging 2 106.09 us 59.42 us 53.04 us 214837 sched-messaging 1 81.70 us 81.70 us 81.70 us 214709 sched-messaging 68 78.44 us 6.83 us 1.15 us 214633 sched-messaging 69 73.71 us 2.69 us 1.07 us 214632 sched-messaging 4 72.62 us 60.83 us 18.15 us 214850 sched-messaging 2 71.75 us 67.60 us 35.88 us 214840 sched-messaging 2 69.29 us 67.53 us 34.65 us 214804 sched-messaging 2 69.00 us 68.23 us 34.50 us 214826 sched-messaging ... Export cgroup__new() function as it's needed from outside. Reviewed-by: Ian Rogers <irogers@google.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Hao Luo <haoluo@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Song Liu <song@kernel.org> Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20230906174903.346486-5-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf lock contention: Add --lock-cgroup optionNamhyung Kim2023-09-121-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The --lock-cgroup option shows lock contention stats break down by cgroups. Add LOCK_AGGR_CGROUP mode and use it instead of use_cgroup field. $ sudo ./perf lock con -ab --lock-cgroup sleep 1 contended total wait max wait avg wait cgroup 8 15.70 us 6.34 us 1.96 us / 2 1.48 us 747 ns 738 ns /user.slice/.../app.slice/app-gnome-google\x2dchrome-6442.scope 1 848 ns 848 ns 848 ns /user.slice/.../session.slice/org.gnome.Shell@x11.service 1 220 ns 220 ns 220 ns /user.slice/.../session.slice/pipewire-pulse.service For now, the cgroup mode only works with BPF (-b). Committer notes: Remove -g as it is used in the other tools with a clear meaning of collect/show callchains. As agreed with Namhyung off list. Reviewed-by: Ian Rogers <irogers@google.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Hao Luo <haoluo@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Song Liu <song@kernel.org> Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20230906174903.346486-4-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf lock contention: Prepare to handle cgroupsNamhyung Kim2023-09-121-2/+7
| | | | | | | | | | | | | | | | | Save cgroup info and display cgroup names if requested. This is a preparation for the next patch. Reviewed-by: Ian Rogers <irogers@google.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Hao Luo <haoluo@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Song Liu <song@kernel.org> Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20230906174903.346486-3-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf lock contention: Update total/bad stats for hidden entriesNamhyung Kim2023-04-061-0/+1
| | | | | | | | | | | | | | | | | | | | | When -E option is used, it only prints the given number of entries but the event stat at the end should have the numbers for entire entries. Likewise, -S option will hide entries that don't have the named function in the callstack. Also update event stat for them. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Hao Luo <haoluo@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Song Liu <song@kernel.org> Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20230406210611.1622492-2-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf lock contention: Add data failure statNamhyung Kim2023-04-061-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's possible to fail to update the data when the lock_stat map is full. We should check that case and show the number at the end. $ sudo ./perf lock con -ablv -E3 -- ./perf bench sched messaging ... contended total wait max wait avg wait address symbol 6157 208.48 ms 69.29 us 33.86 us ffff934c001c1f00 (spinlock) 4030 72.04 ms 61.84 us 17.88 us ffff934c000415c0 (spinlock) 3201 50.30 ms 47.73 us 15.71 us ffff934c2eead850 (spinlock) === output for debug === bad: 0, total: 13388 bad rate: 0.00 % histogram of failure reasons task: 0 stack: 0 time: 0 data: 0 <----- added Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Hao Luo <haoluo@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Song Liu <song@kernel.org> Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20230406210611.1622492-2-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf lock contention: Show detail failure reason for BPFNamhyung Kim2023-04-041-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It can fail to collect lock stat from BPF for various reasons. For example, I've got a report that sometimes time calculation seems wrong in case of contended spinlocks. I suspect the time delta went negative for some reason. Count them separately and show in the output like below: $ sudo perf lock contention -abE5 sleep 10 contended total wait max wait avg wait type caller 13 785.61 us 79.36 us 60.43 us spinlock remove_wait_queue+0x14 10 469.02 us 87.51 us 46.90 us spinlock prepare_to_wait+0x27 9 289.09 us 69.08 us 32.12 us spinlock finish_wait+0x36 114 251.05 us 8.56 us 2.20 us spinlock try_to_wake_up+0x1f5 132 188.63 us 5.01 us 1.43 us spinlock __wake_up_common_lock+0x62 === output for debug === bad: 1, total: 279 bad rate: 0.36 % histogram of failure reasons task: 1 stack: 0 time: 0 Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Hao Luo <haoluo@google.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20230327225711.245738-1-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf lock contention: Add -o/--lock-owner optionNamhyung Kim2023-02-081-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When there're many lock contentions in the system, people sometimes want to know who caused the contention, IOW who's the owner of the locks. The -o/--lock-owner option tries to follow the lock owners for the contended mutexes and rwsems from BPF, and then attributes the contention time to the owner instead of the waiter. It's a best effort approach to get the owner info at the time of the contention and doesn't guarantee to have the precise tracking of owners if it's changing over time. Currently it only handles mutex and rwsem that have owner field in their struct and it basically points to a task_struct that owns the lock at the moment. Technically its type is atomic_long_t and it comes with some LSB bits used for other meanings. So it needs to clear them when casting it to a pointer to task_struct. Also the atomic_long_t is a typedef of the atomic 32 or 64 bit types depending on arch which is a wrapper struct for the counter value. I'm not aware of proper ways to access those kernel atomic types from BPF so I just read the internal counter value directly. Please let me know if there's a better way. When -o/--lock-owner option is used, it goes to the task aggregation mode like -t/--threads option does. However it cannot get the owner for other lock types like spinlock and sometimes even for mutex. $ sudo ./perf lock con -abo -- ./perf bench sched pipe # Running 'sched/pipe' benchmark: # Executed 1000000 pipe operations between two processes Total time: 4.766 [sec] 4.766540 usecs/op 209795 ops/sec contended total wait max wait avg wait pid owner 403 565.32 us 26.81 us 1.40 us -1 Unknown 4 27.99 us 8.57 us 7.00 us 1583145 sched-pipe 1 8.25 us 8.25 us 8.25 us 1583144 sched-pipe 1 2.03 us 2.03 us 2.03 us 5068 chrome As you can see, the owner is unknown for the most cases. But if we filter only for the mutex locks, it'd more likely get the onwers. $ sudo ./perf lock con -abo -Y mutex -- ./perf bench sched pipe # Running 'sched/pipe' benchmark: # Executed 1000000 pipe operations between two processes Total time: 4.910 [sec] 4.910435 usecs/op 203647 ops/sec contended total wait max wait avg wait pid owner 2 15.50 us 8.29 us 7.75 us 1582852 sched-pipe 7 7.20 us 2.47 us 1.03 us -1 Unknown 1 6.74 us 6.74 us 6.74 us 1582851 sched-pipe Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Hao Luo <haoluo@google.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Song Liu <song@kernel.org> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will@kernel.org> Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20230207002403.63590-3-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf lock contention: Support filters for different aggregationNamhyung Kim2023-02-031-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It'd be useful to filter other than the current aggregation mode. For example, users may want to see callstacks for specific locks only. Or they may want tasks from a certain callstack. The tracepoints already collected the information but it needs to check the condition again when processing the event. And it needs to change BPF to allow the key combinations. The lock contentions on 'rcu_state' spinlock can be monitored: $ sudo perf lock con -abv -L rcu_state sleep 1 ... contended total wait max wait avg wait type caller 4 151.39 us 62.57 us 37.85 us spinlock rcu_core+0xcb 0xffffffff81fd1666 _raw_spin_lock_irqsave+0x46 0xffffffff8172d76b rcu_core+0xcb 0xffffffff822000eb __softirqentry_text_start+0xeb 0xffffffff816a0ba9 __irq_exit_rcu+0xc9 0xffffffff81fc0112 sysvec_apic_timer_interrupt+0xa2 0xffffffff82000e46 asm_sysvec_apic_timer_interrupt+0x16 0xffffffff81d49f78 cpuidle_enter_state+0xd8 0xffffffff81d4a259 cpuidle_enter+0x29 1 30.21 us 30.21 us 30.21 us spinlock rcu_core+0xcb 0xffffffff81fd1666 _raw_spin_lock_irqsave+0x46 0xffffffff8172d76b rcu_core+0xcb 0xffffffff822000eb __softirqentry_text_start+0xeb 0xffffffff816a0ba9 __irq_exit_rcu+0xc9 0xffffffff81fc00c4 sysvec_apic_timer_interrupt+0x54 0xffffffff82000e46 asm_sysvec_apic_timer_interrupt+0x16 1 28.84 us 28.84 us 28.84 us spinlock rcu_accelerate_cbs_unlocked+0x40 0xffffffff81fd1c60 _raw_spin_lock+0x30 0xffffffff81728cf0 rcu_accelerate_cbs_unlocked+0x40 0xffffffff8172da82 rcu_core+0x3e2 0xffffffff822000eb __softirqentry_text_start+0xeb 0xffffffff816a0ba9 __irq_exit_rcu+0xc9 0xffffffff81fc0112 sysvec_apic_timer_interrupt+0xa2 0xffffffff82000e46 asm_sysvec_apic_timer_interrupt+0x16 0xffffffff81d49f78 cpuidle_enter_state+0xd8 ... To see tasks calling 'rcu_core' function: $ sudo perf lock con -abt -S rcu_core sleep 1 contended total wait max wait avg wait pid comm 19 23.46 us 2.21 us 1.23 us 0 swapper 2 18.37 us 17.01 us 9.19 us 2061859 ThreadPoolForeg 3 5.76 us 1.97 us 1.92 us 3909 pipewire-pulse 1 2.26 us 2.26 us 2.26 us 1809271 MediaSu~isor #2 1 1.97 us 1.97 us 1.97 us 1514882 Chrome_ChildIOT 1 987 ns 987 ns 987 ns 3740 pipewire-pulse Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Hao Luo <haoluo@google.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Song Liu <song@kernel.org> Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20230203021324.143540-4-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf lock contention: Use lock_stat_find{,new}Namhyung Kim2023-02-031-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | This is a preparation work to support complex keys of BPF maps. Now it has single value key according to the aggregation mode like stack_id or pid. But we want to use a combination of those keys. Then lock_contention_read() should still aggregate the result based on the key that was requested by user. The other key info will be used for filtering. So instead of creating a lock_stat entry always, Check if it's already there using lock_stat_find() first. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Hao Luo <haoluo@google.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Song Liu <song@kernel.org> Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20230203021324.143540-3-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf lock contention: Add -S/--callstack-filter optionNamhyung Kim2023-02-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The -S/--callstack-filter is to limit display entries having the given string in the callstack (not only in the caller in the output). The following example shows lock contention results if the callstack has 'net' substring somewhere. Note that the caller '__dev_queue_xmit' does not match to it, but it has 'inet6_csk_xmit' in the callstack. This applies even if you don't use -v option to show the full callstack. $ sudo ./perf lock con -abv -S net sleep 1 ... contended total wait max wait avg wait type caller 5 70.20 us 16.13 us 14.04 us spinlock __dev_queue_xmit+0xb6d 0xffffffffa5dd1c60 _raw_spin_lock+0x30 0xffffffffa5b8f6ed __dev_queue_xmit+0xb6d 0xffffffffa5cd8267 ip6_finish_output2+0x2c7 0xffffffffa5cdac14 ip6_finish_output+0x1d4 0xffffffffa5cdb477 ip6_xmit+0x457 0xffffffffa5d1fd17 inet6_csk_xmit+0xd7 0xffffffffa5c5f4aa __tcp_transmit_skb+0x54a 0xffffffffa5c6467d tcp_keepalive_timer+0x2fd Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Song Liu <song@kernel.org> Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20230126000936.3017683-1-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf lock contention: Add -L/--lock-filter optionNamhyung Kim2022-12-211-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The -L/--lock-filter option is to filter only given locks. The locks can be specified by address or name (if exists). $ sudo ./perf lock record -a sleep 1 $ sudo ./perf lock con -l contended total wait max wait avg wait address symbol 57 1.11 ms 42.83 us 19.54 us ffff9f4140059000 15 280.88 us 23.51 us 18.73 us ffffffff9d007a40 jiffies_lock 1 20.49 us 20.49 us 20.49 us ffffffff9d0d50c0 rcu_state 1 9.02 us 9.02 us 9.02 us ffff9f41759e9ba0 $ sudo ./perf lock con -L jiffies_lock,rcu_state contended total wait max wait avg wait type caller 15 280.88 us 23.51 us 18.73 us spinlock tick_sched_do_timer+0x93 1 20.49 us 20.49 us 20.49 us spinlock __softirqentry_text_start+0xeb $ sudo ./perf lock con -L ffff9f4140059000 contended total wait max wait avg wait type caller 38 779.40 us 42.83 us 20.51 us spinlock worker_thread+0x50 11 216.30 us 39.87 us 19.66 us spinlock queue_work_on+0x39 8 118.13 us 20.51 us 14.77 us spinlock kthread+0xe5 Committer testing: # uname -a Linux quaco 6.0.12-200.fc36.x86_64 #1 SMP PREEMPT_DYNAMIC Thu Dec 8 17:15:53 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux # perf lock record ^C[ perf record: Woken up 1 times to write data ] # perf lock con -L jiffies_lock,rcu_state contended total wait max wait avg wait type caller # perf lock con contended total wait max wait avg wait type caller 1 9.06 us 9.06 us 9.06 us spinlock call_timer_fn+0x24 # perf lock con -L call ignore unknown symbol: call contended total wait max wait avg wait type caller 1 9.06 us 9.06 us 9.06 us spinlock call_timer_fn+0x24 # Signed-off-by: Namhyung Kim <namhyung@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Blake Jones <blakejones@google.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Song Liu <song@kernel.org> Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20221219201732.460111-5-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf lock contention: Support lock type filtering for BPFNamhyung Kim2022-12-211-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Likewise, add type_filter BPF hash map and check it when user gave a lock type filter. $ sudo ./perf lock con -ab -Y rwlock -- ./perf bench sched messaging # Running 'sched/messaging' benchmark: # 20 sender and receiver processes per group # 10 groups == 400 processes run Total time: 0.203 [sec] contended total wait max wait avg wait type caller 15 156.19 us 19.45 us 10.41 us rwlock:W do_exit+0x36d 1 11.12 us 11.12 us 11.12 us rwlock:R do_wait+0x8b 1 5.09 us 5.09 us 5.09 us rwlock:W release_task+0x6e Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Blake Jones <blakejones@google.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Song Liu <song@kernel.org> Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20221219201732.460111-4-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf lock contention: Add -Y/--type-filter optionNamhyung Kim2022-12-211-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The -Y/--type-filter option is to filter the result for specific lock types only. It can accept comma-separated values. Note that it would accept type names like one in the output. spinlock, mutex, rwsem:R and so on. For RW-variant lock types, it converts the name to the both variants. In other words, "rwsem" is same as "rwsem:R,rwsem:W". Also note that "mutex" has two different encoding - one for sleeping wait, another for optimistic spinning. Add "mutex-spin" entry for the lock_type_table so that we can add it for "mutex" under the table. $ sudo ./perf lock record -a -- ./perf bench sched messaging $ sudo ./perf lock con -E 5 -Y spinlock contended total wait max wait avg wait type caller 802 1.26 ms 11.73 us 1.58 us spinlock __wake_up_common_lock+0x62 13 787.16 us 105.44 us 60.55 us spinlock remove_wait_queue+0x14 12 612.96 us 78.70 us 51.08 us spinlock prepare_to_wait+0x27 114 340.68 us 12.61 us 2.99 us spinlock try_to_wake_up+0x1f5 83 226.38 us 9.15 us 2.73 us spinlock folio_lruvec_lock_irqsave+0x5e Committer notes: Make get_type_flag() return UINT_MAX for error instad of -1UL, as that function returns 'unsigned int' and we store the value on a 'unsigned int' 'flags' variable which makes clang unhappy: 35 98.23 fedora:37 : FAIL clang version 15.0.6 (Fedora 15.0.6-1.fc37) builtin-lock.c:2012:14: error: result of comparison of constant 18446744073709551615 with expression of type 'unsigned int' is always true [-Werror,-Wtautological-constant-out-of-range-compare] if (flags != -1UL) { ~~~~~ ^ ~~~~ builtin-lock.c:2021:14: error: result of comparison of constant 18446744073709551615 with expression of type 'unsigned int' is always true [-Werror,-Wtautological-constant-out-of-range-compare] if (flags != -1UL) { ~~~~~ ^ ~~~~ builtin-lock.c:2037:14: error: result of comparison of constant 18446744073709551615 with expression of type 'unsigned int' is always true [-Werror,-Wtautological-constant-out-of-range-compare] if (flags != -1UL) { ~~~~~ ^ ~~~~ 3 errors generated. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Blake Jones <blakejones@google.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Song Liu <song@kernel.org> Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20221219201732.460111-3-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf lock contention: Implement -t/--threads option for BPFNamhyung Kim2022-12-141-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | The BPF didn't show the per-thread stat properly. Use task's thread id (PID) as a key instead of stack_id and add a task_data map to save task comm names. $ sudo ./perf lock con -abt -E 5 sleep 1 contended total wait max wait avg wait pid comm 1 740.66 ms 740.66 ms 740.66 ms 1950 nv_queue 3 305.50 ms 298.19 ms 101.83 ms 1884 nvidia-modeset/ 1 25.14 us 25.14 us 25.14 us 2725038 EventManager_De 12 23.09 us 9.30 us 1.92 us 0 swapper 1 20.18 us 20.18 us 20.18 us 2725033 EventManager_De Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Blake Jones <blakejones@google.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Song Liu <song@kernel.org> Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20221209190727.759804-3-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* machine: Adopt is_lock_function() from builtin-lock.cArnaldo Carvalho de Melo2022-12-141-2/+0
| | | | | | | | | | | | | | | | | | | | | | | It is used in bpf_lock_contention.c and builtin-lock.c will be made CONFIG_LIBTRACEEVENT=y conditional, so move it to machine.c, that is always available. This makes those 4 global variables for sched and lock text start and end to move to 'struct machine' too, as conceivably we can have that info for several machine instances, say some 'perf diff' like tool. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: bpf@vger.kernel.org Link: http://lore.kernel.org/lkml/ Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf lock contention: Increase default stack skip to 4Namhyung Kim2022-10-311-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In most configurations, it works well with skipping 4 entries by default. If some systems still have 3 BPF internal stack frames, the next frame should be in a lock function which will be skipped later when it tries to find a caller. So increasing to 4 won't affect such systems too. With --stack-skip=0, I can see something like this: 24 49.84 us 7.41 us 2.08 us mutex bpf_prog_e1b85959d520446c_contention_begin+0x12e 0xffffffffc045040e bpf_prog_e1b85959d520446c_contention_begin+0x12e 0xffffffffc045040e bpf_prog_e1b85959d520446c_contention_begin+0x12e 0xffffffff82ea2071 bpf_trace_run2+0x51 0xffffffff82de775b __bpf_trace_contention_begin+0xb 0xffffffff82c02045 __mutex_lock+0x245 0xffffffff82c019e3 __mutex_lock_slowpath+0x13 0xffffffff82c019c0 mutex_lock+0x20 0xffffffff830a083c kernfs_iop_permission+0x2c Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Song Liu <song@kernel.org> Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20221028180128.3311491-5-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf lock contention: Fix a build error on 32-bitNamhyung Kim2022-10-061-1/+1
| | | | | | | | | | | | | | | | | | It was reported that it failed to build the BPF lock contention skeleton on 32 bit arch due to the size of long. The lost count is used only for reporting errors due to lack of stackmap space through bad_hist which type is 'int'. Let's use int type then. Fixes: 6d499a6b3d90277d ("perf lock: Print the number of lost entries for BPF") Reported-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Song Liu <songliubraving@fb.com> Link: http://lore.kernel.org/lkml/20220926215638.3931222-1-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf lock contention: Allow to change stack depth and skipNamhyung Kim2022-10-041-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It needs stack traces to find callers of locks. To minimize the performance overhead it only collects up to 8 entries for each stack trace. And it skips first 3 entries as they came from BPF, tracepoint and lock functions which are not interested for most users. But it turned out that those numbers are different in some configuration. Using fixed number can result in non meaningful caller names. Let's make them adjustable with --stack-depth and --skip-stack options. On my setup, the default output is like below: # /perf lock con -ab -F contended,wait_total sleep 3 contended total wait type caller 28 4.55 ms rwlock:W __bpf_trace_contention_begin+0xb 33 1.67 ms rwlock:W __bpf_trace_contention_begin+0xb 12 580.28 us spinlock __bpf_trace_contention_begin+0xb 60 240.54 us rwsem:R __bpf_trace_contention_begin+0xb 27 64.45 us spinlock __bpf_trace_contention_begin+0xb If I change the stack skip to 5, the result will be like: # perf lock con -ab -F contended,wait_total --stack-skip 5 sleep 3 contended total wait type caller 32 715.45 us spinlock folio_lruvec_lock_irqsave+0x61 26 550.22 us spinlock folio_lruvec_lock_irqsave+0x61 15 486.93 us rwsem:R mmap_read_lock+0x13 12 139.66 us rwsem:W vm_mmap_pgoff+0x93 1 7.04 us spinlock tick_do_update_jiffies64+0x25 Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Song Liu <songliubraving@fb.com> Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20220912055314.744552-4-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf lock contention: Show full callstack with -v optionNamhyung Kim2022-10-041-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently it shows a caller function for each entry, but users need to see the full call stacks sometimes. Use -v/--verbose option to do that. # perf lock con -a -b -v sleep 3 Looking at the vmlinux_path (8 entries long) symsrc__init: cannot get elf header. Using /proc/kcore for kernel data Using /proc/kallsyms for symbols contended total wait max wait avg wait type caller 1 10.74 us 10.74 us 10.74 us spinlock __bpf_trace_contention_begin+0xb 0xffffffffc03b5c47 bpf_prog_bf07ae9e2cbd02c5_contention_begin+0x117 0xffffffffc03b5c47 bpf_prog_bf07ae9e2cbd02c5_contention_begin+0x117 0xffffffffbb8b8e75 bpf_trace_run2+0x35 0xffffffffbb7eab9b __bpf_trace_contention_begin+0xb 0xffffffffbb7ebe75 queued_spin_lock_slowpath+0x1f5 0xffffffffbc1c26ff _raw_spin_lock+0x1f 0xffffffffbb841015 tick_do_update_jiffies64+0x25 0xffffffffbb8409ee tick_irq_enter+0x9e 1 7.70 us 7.70 us 7.70 us spinlock __bpf_trace_contention_begin+0xb 0xffffffffc03b5c47 bpf_prog_bf07ae9e2cbd02c5_contention_begin+0x117 0xffffffffc03b5c47 bpf_prog_bf07ae9e2cbd02c5_contention_begin+0x117 0xffffffffbb8b8e75 bpf_trace_run2+0x35 0xffffffffbb7eab9b __bpf_trace_contention_begin+0xb 0xffffffffbb7ebe75 queued_spin_lock_slowpath+0x1f5 0xffffffffbc1c26ff _raw_spin_lock+0x1f 0xffffffffbb7bc27e raw_spin_rq_lock_nested+0xe 0xffffffffbb7cef9c load_balance+0x66c Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Song Liu <songliubraving@fb.com> Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20220912055314.744552-3-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf lock: Print the number of lost entries for BPFNamhyung Kim2022-08-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Like the normal 'perf lock contention' output, it'd print the number of lost entries for BPF if exists or -v option is passed. Currently it uses BROKEN_CONTENDED stat for the lost count (due to full stack maps). $ sudo perf lock con -a -b --map-nr-entries 128 sleep 5 ... === output for debug=== bad: 43, total: 14903 bad rate: 0.29 % histogram of events caused bad sequence acquire: 0 acquired: 0 contended: 43 release: 0 Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Blake Jones <blakejones@google.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Song Liu <songliubraving@fb.com> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20220802191004.347740-3-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf lock: Add --map-nr-entries optionNamhyung Kim2022-08-021-0/+1
| | | | | | | | | | | | | | | | | | | The --map-nr-entries option is to control number of max entries in the perf lock contention BPF maps. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Blake Jones <blakejones@google.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Song Liu <songliubraving@fb.com> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20220802191004.347740-2-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf lock: Introduce struct lock_contentionNamhyung Kim2022-08-021-6/+11
| | | | | | | | | | | | | | | | | | | The lock_contention struct is to carry related fields together and to minimize the change when we add new config options. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Blake Jones <blakejones@google.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Song Liu <songliubraving@fb.com> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20220802191004.347740-1-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf lock: Implement cpu and task filters for BPFNamhyung Kim2022-08-011-2/+9
| | | | | | | | | | | | | | | | | | | | | | | Add -a/--all-cpus and -C/--cpu options for cpu filtering. Also -p/--pid and --tid options are added for task filtering. The short -t option is taken for --threads already. Tracking the command line workload is possible as well. $ sudo perf lock contention -a -b sleep 1 Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Blake Jones <blakejones@google.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20220729200756.666106-4-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf lock: Use BPF for lock contention analysisNamhyung Kim2022-08-011-0/+133
Add -b/--use-bpf option to use BPF to collect lock contention stats. For simplicity it now runs system-wide and requires C-c to stop. Upcoming changes will add the usual filtering. $ sudo perf lock con -b ^C contended total wait max wait avg wait type caller 42 192.67 us 13.64 us 4.59 us spinlock queue_work_on+0x20 23 85.54 us 10.28 us 3.72 us spinlock worker_thread+0x14a 6 13.92 us 6.51 us 2.32 us mutex kernfs_iop_permission+0x30 3 11.59 us 10.04 us 3.86 us mutex kernfs_dop_revalidate+0x3c 1 7.52 us 7.52 us 7.52 us spinlock kthread+0x115 1 7.24 us 7.24 us 7.24 us rwlock:W sys_epoll_wait+0x148 2 7.08 us 3.99 us 3.54 us spinlock delayed_work_timer_fn+0x1b 1 6.41 us 6.41 us 6.41 us spinlock idle_balance+0xa06 2 2.50 us 1.83 us 1.25 us mutex kernfs_iop_lookup+0x2f 1 1.71 us 1.71 us 1.71 us mutex kernfs_iop_getattr+0x2c Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Blake Jones <blakejones@google.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20220729200756.666106-3-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>