kernel/tools/perf/util/bpf_lock_contention.c, branch linux-6.2.y

perf lock contention: Support lock addr/name filtering for BPF

2022-12-21T17:52:39Z

Likewise, add addr_filter BPF hash map and check it with the lock address. $ sudo ./perf lock con -ab -L tasklist_lock -- ./perf bench sched messaging # Running 'sched/messaging' benchmark: # 20 sender and receiver processes per group # 10 groups == 400 processes run Total time: 0.169 [sec] contended total wait max wait avg wait type caller 18 174.09 us 25.31 us 9.67 us rwlock:W do_exit+0x36d 5 32.34 us 10.87 us 6.47 us rwlock:R do_wait+0x8b 4 15.41 us 4.73 us 3.85 us rwlock:W release_task+0x6e Signed-off-by: Namhyung Kim Cc: Adrian Hunter Cc: Blake Jones Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Peter Zijlstra Cc: Song Liu Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20221219201732.460111-6-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf lock contention: Support lock type filtering for BPF

2022-12-21T17:52:39Z

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 Cc: Adrian Hunter Cc: Blake Jones Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Peter Zijlstra Cc: Song Liu Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20221219201732.460111-4-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Fix usage of the verbose variable

2022-12-20T18:16:33Z

The data type of the verbose variable is integer and can be negative, replace improperly used cases in a unified manner: 1. if (verbose) => if (verbose > 0) 2. if (!verbose) => if (verbose <= 0) 3. if (XX && verbose) => if (XX && verbose > 0) 4. if (XX && !verbose) => if (XX && verbose <= 0) Reviewed-by: Adrian Hunter Signed-off-by: Yang Jihong Cc: Alexander Shishkin Cc: Andi Kleen Cc: Carsten Haitzler Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Leo Yan Cc: Mark Rutland Cc: Martin KaFai Lau Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Ravi Bangoria Link: https://lore.kernel.org/r/20221220035702.188413-3-yangjihong1@huawei.com Signed-off-by: Arnaldo Carvalho de Melo

perf lock contention: Add -l/--lock-addr option

2022-12-14T14:24:31Z

The -l/--lock-addr option is to implement per-lock-instance contention stat using LOCK_AGGR_ADDR. It displays lock address and optionally symbol name if exists. $ sudo ./perf lock con -abl sleep 1 contended total wait max wait avg wait address symbol 1 36.28 us 36.28 us 36.28 us ffff92615d6448b8 9 10.91 us 1.84 us 1.21 us ffffffffbaed50c0 rcu_state 1 10.49 us 10.49 us 10.49 us ffff9262ac4f0c80 8 4.68 us 1.67 us 585 ns ffffffffbae07a40 jiffies_lock 3 3.03 us 1.45 us 1.01 us ffff9262277861e0 1 924 ns 924 ns 924 ns ffff926095ba9d20 1 436 ns 436 ns 436 ns ffff9260bfda4f60 Signed-off-by: Namhyung Kim Cc: Adrian Hunter Cc: Blake Jones Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Peter Zijlstra Cc: Song Liu Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20221209190727.759804-4-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf lock contention: Implement -t/--threads option for BPF

2022-12-14T14:24:31Z

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 Cc: Adrian Hunter Cc: Blake Jones Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Peter Zijlstra Cc: Song Liu Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20221209190727.759804-3-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf lock contention: Add lock_data.h for common data

2022-12-14T14:24:31Z

Accessing BPF maps should use the same data types. Add bpf_skel/lock_data.h to define the common data structures. No functional changes. Committer notes: Fixed contention_key.stack_id missing rename to contention_key.stack_or_task_id. Signed-off-by: Namhyung Kim Cc: Adrian Hunter Cc: Blake Jones Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Peter Zijlstra Cc: Song Liu Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20221209190727.759804-2-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

machine: Adopt is_lock_function() from builtin-lock.c

2022-12-14T14:16:12Z

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 Cc: Alexander Shishkin Cc: Ian Rogers Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Nick Desaulniers Cc: Peter Zijlstra Cc: Stephane Eranian Cc: bpf@vger.kernel.org Link: http://lore.kernel.org/lkml/ Signed-off-by: Arnaldo Carvalho de Melo

perf lock contention: Do not use BPF task local storage

2022-11-23T13:42:28Z

It caused some troubles when a lock inside kmalloc is contended because task local storage would allocate memory using kmalloc. It'd create a recusion and even crash in my system. There could be a couple of workarounds but I think the simplest one is to use a pre-allocated hash map. We could fix the task local storage to use the safe BPF allocator, but it takes time so let's change this until it happens actually. Signed-off-by: Namhyung Kim Acked-by: Martin KaFai Lau Cc: Adrian Hunter Cc: Blake Jones Cc: Chris Li Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Peter Zijlstra Cc: Song Liu Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20221118190109.1512674-1-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf lock contention: Avoid variable length arrays

2022-10-31T14:07:45Z

The msan also warns about the use of VLA for stack_trace variable. We can dynamically allocate instead. While at it, simplify the error handle a bit (and fix bugs). Signed-off-by: Namhyung Kim Cc: Adrian Hunter Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20221028180128.3311491-4-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf lock contention: Fix memory sanitizer issue

2022-10-31T14:07:29Z

The msan reported a use-of-uninitialized-value warning for the struct lock_contention_data in lock_contention_read(). While it'd be filled by bpf_map_lookup_elem(), let's just initialize it to silence the warning. ==12524==WARNING: MemorySanitizer: use-of-uninitialized-value #0 0x562b0f16b1cd in lock_contention_read util/bpf_lock_contention.c:139:7 #1 0x562b0ef65ec6 in __cmd_contention builtin-lock.c:1737:3 #2 0x562b0ef65ec6 in cmd_lock builtin-lock.c:1992:8 #3 0x562b0ee7f50b in run_builtin perf.c:322:11 #4 0x562b0ee7efc1 in handle_internal_command perf.c:376:8 #5 0x562b0ee7e1e9 in run_argv perf.c:420:2 #6 0x562b0ee7e1e9 in main perf.c:550:3 #7 0x7f065f10e632 in __libc_start_main (/usr/lib64/libc.so.6+0x61632) #8 0x562b0edf2fa9 in _start (perf+0xfa9) SUMMARY: MemorySanitizer: use-of-uninitialized-value (perf+0xe15160) in lock_contention_read Signed-off-by: Namhyung Kim Cc: Adrian Hunter Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20221028180128.3311491-2-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo