BMC/Intel-BMC/linux.git/tools/perf/util/evsel.c, branch dev-4.6

perf evsel: Handle EACCESS + perf_event_paranoid=2 in fallback()

2016-05-12T19:13:16+00:00

Now with the default for the kernel.perf_event_paranoid sysctl being 2 [1] we need to fall back to :u, i.e. to set perf_event_attr.exclude_kernel to 1. Before: [acme@jouet linux]$ perf record usleep 1 Error: You may not have permission to collect stats. Consider tweaking /proc/sys/kernel/perf_event_paranoid, which controls use of the performance events system by unprivileged users (without CAP_SYS_ADMIN). The current value is 2: -1: Allow use of (almost) all events by all users >= 0: Disallow raw tracepoint access by users without CAP_IOC_LOCK >= 1: Disallow CPU event access by users without CAP_SYS_ADMIN >= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN [acme@jouet linux]$ After: [acme@jouet linux]$ perf record usleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.016 MB perf.data (7 samples) ] [acme@jouet linux]$ perf evlist cycles:u [acme@jouet linux]$ perf evlist -v cycles:u: size: 112, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|PERIOD, disabled: 1, inherit: 1, exclude_kernel: 1, mmap: 1, comm: 1, freq: 1, enable_on_exec: 1, task: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1 [acme@jouet linux]$ And if the user turns on verbose mode, an explanation will appear: [acme@jouet linux]$ perf record -v usleep 1 Warning: kernel.perf_event_paranoid=2, trying to fall back to excluding kernel samples mmap size 528384B [ perf record: Woken up 1 times to write data ] Looking at the vmlinux_path (8 entries long) Using /lib/modules/4.6.0-rc7+/build/vmlinux for symbols [ perf record: Captured and wrote 0.016 MB perf.data (7 samples) ] [acme@jouet linux]$ [1] 0161028b7c8a ("perf/core: Change the default paranoia level to 2") Reported-by: Ingo Molnar Cc: Adrian Hunter Cc: Andy Lutomirski Cc: David Ahern Cc: Jiri Olsa Cc: Kees Cook Cc: Linus Torvalds Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-b20jmx4dxt5hpaa9t2rroi0o@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf evsel: Improve EPERM error handling in open_strerror()

2016-05-12T18:44:55+00:00

We were showing a hardcoded default value for the kernel.perf_event_paranoid sysctl, now that it became more paranoid (1 -> 2 [1]), this would need to be updated, instead show the current value: [acme@jouet linux]$ perf record ls Error: You may not have permission to collect stats. Consider tweaking /proc/sys/kernel/perf_event_paranoid, which controls use of the performance events system by unprivileged users (without CAP_SYS_ADMIN). The current value is 2: -1: Allow use of (almost) all events by all users >= 0: Disallow raw tracepoint access by users without CAP_IOC_LOCK >= 1: Disallow CPU event access by users without CAP_SYS_ADMIN >= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN [acme@jouet linux]$ [1] 0161028b7c8a ("perf/core: Change the default paranoia level to 2") Reported-by: Ingo Molnar Cc: Adrian Hunter Cc: Andy Lutomirski Cc: David Ahern Cc: Jiri Olsa Cc: Kees Cook Cc: Linus Torvalds Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-0gc4rdpg8d025r5not8s8028@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Add cpumode to struct perf_sample

2016-03-23T15:03:07+00:00

To avoid parsing event->header.misc in many locations. This will also allow setting perf.sample.{ip,cpumode} in a single place, from tracepoint fields, as needed by 'perf kvm' with PPC guests, where the guest hardware counters is not available at the host. Cc: Adrian Hunter Cc: Hemant Kumar Cc: Jiri Olsa Cc: Namhyung Kim Cc: Naveen N. Rao Cc: Ravi Bangoria Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-qp3yradhyt6q3wl895b1aat0@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Introduce bpf-output event

2016-02-22T17:37:21+00:00

Commit a43eec304259 ("bpf: introduce bpf_perf_event_output() helper") adds a helper to enable a BPF program to output data to a perf ring buffer through a new type of perf event, PERF_COUNT_SW_BPF_OUTPUT. This patch enables perf to create events of that type. Now a perf user can use the following cmdline to receive output data from BPF programs: # perf record -a -e bpf-output/no-inherit,name=evt/ \ -e ./test_bpf_output.c/map:channel.event=evt/ ls / # perf script perf 1560 [004] 347747.086295: evt: ffffffff811fd201 sys_write ... perf 1560 [004] 347747.086300: evt: ffffffff811fd201 sys_write ... perf 1560 [004] 347747.086315: evt: ffffffff811fd201 sys_write ... ... Test result: # cat test_bpf_output.c /************************ BEGIN **************************/ #include struct bpf_map_def { unsigned int type; unsigned int key_size; unsigned int value_size; unsigned int max_entries; }; #define SEC(NAME) __attribute__((section(NAME), used)) static u64 (*ktime_get_ns)(void) = (void *)BPF_FUNC_ktime_get_ns; static int (*trace_printk)(const char *fmt, int fmt_size, ...) = (void *)BPF_FUNC_trace_printk; static int (*get_smp_processor_id)(void) = (void *)BPF_FUNC_get_smp_processor_id; static int (*perf_event_output)(void *, struct bpf_map_def *, int, void *, unsigned long) = (void *)BPF_FUNC_perf_event_output; struct bpf_map_def SEC("maps") channel = { .type = BPF_MAP_TYPE_PERF_EVENT_ARRAY, .key_size = sizeof(int), .value_size = sizeof(u32), .max_entries = __NR_CPUS__, }; SEC("func_write=sys_write") int func_write(void *ctx) { struct { u64 ktime; int cpuid; } __attribute__((packed)) output_data; char error_data[] = "Error: failed to output: %d\n"; output_data.cpuid = get_smp_processor_id(); output_data.ktime = ktime_get_ns(); int err = perf_event_output(ctx, &channel, get_smp_processor_id(), &output_data, sizeof(output_data)); if (err) trace_printk(error_data, sizeof(error_data), err); return 0; } char _license[] SEC("license") = "GPL"; int _version SEC("version") = LINUX_VERSION_CODE; /************************ END ***************************/ # perf record -a -e bpf-output/no-inherit,name=evt/ \ -e ./test_bpf_output.c/map:channel.event=evt/ ls / # perf script | grep ls ls 2242 [003] 347851.557563: evt: ffffffff811fd201 sys_write ... ls 2242 [003] 347851.557571: evt: ffffffff811fd201 sys_write ... Signed-off-by: Wang Nan Cc: Adrian Hunter Cc: Alexei Starovoitov Cc: Brendan Gregg Cc: Cody P Schafer Cc: He Kuang Cc: Jeremie Galarneau Cc: Jiri Olsa Cc: Kirill Smelkov Cc: Li Zefan Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1456132275-98875-11-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo

perf record: Add --all-user/--all-kernel options

2016-02-18T13:48:44+00:00

Allow user to easily switch all events to user or kernel space with simple --all-user or --all-kernel options. This will be handy within perf mem/c2c wrappers to switch easily monitoring modes. Committer note: Testing it: # perf record --all-kernel --all-user -a sleep 2 Error: option `all-user' cannot be used with all-kernel Usage: perf record [] [] or: perf record [] -- [] --all-user Configure all used events to run in user space. --all-kernel Configure all used events to run in kernel space. # perf record --all-user --all-kernel -a sleep 2 Error: option `all-kernel' cannot be used with all-user Usage: perf record [] [] or: perf record [] -- [] --all-kernel Configure all used events to run in kernel space. --all-user Configure all used events to run in user space. # perf record --all-user -a sleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 1.416 MB perf.data (162 samples) ] # perf report | grep '\[k\]' # perf record --all-kernel -a sleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 1.423 MB perf.data (296 samples) ] # perf report | grep '\[\.\]' # Signed-off-by: Jiri Olsa Tested-by: Arnaldo Carvalho de Melo Cc: Andi Kleen Cc: David Ahern Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/r/1455525293-8671-2-git-send-email-jolsa@kernel.org [ Made those options to be mutually exclusive ] Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Document the perf sysctls

2016-01-26T14:52:45+00:00

perf_event_paranoid was only documented in source code and a perf error message. Copy the documentation from the error message to Documentation/sysctl/kernel.txt. perf_cpu_time_max_percent was already documented but missing from the list at the top, so add it there. Signed-off-by: Ben Hutchings Cc: Peter Zijlstra Cc: linux-doc@vger.kernel.org Link: http://lkml.kernel.org/r/20160119213515.GG2637@decadent.org.uk [ Remove reference to external Documentation file, provide info inline, as before ] Signed-off-by: Arnaldo Carvalho de Melo

perf evlist: Add --trace-fields option to show trace fields

2016-01-08T17:23:02+00:00

To use dynamic sort keys, it might be good to add an option to see the list of field names. $ perf evlist -i perf.data.sched sched:sched_switch sched:sched_stat_wait sched:sched_stat_sleep sched:sched_stat_iowait sched:sched_stat_runtime sched:sched_process_fork sched:sched_wakeup sched:sched_wakeup_new sched:sched_migrate_task # Tip: use 'perf evlist --trace-fields' to show fields for tracepoint events $ perf evlist -i perf.data.sched --trace-fields sched:sched_switch: trace_fields: prev_comm,prev_pid,prev_prio,prev_state,next_comm,next_pid,next_prio sched:sched_stat_wait: trace_fields: comm,pid,delay sched:sched_stat_sleep: trace_fields: comm,pid,delay sched:sched_stat_iowait: trace_fields: comm,pid,delay sched:sched_stat_runtime: trace_fields: comm,pid,runtime,vruntime sched:sched_process_fork: trace_fields: parent_comm,parent_pid,child_comm,child_pid sched:sched_wakeup: trace_fields: comm,pid,prio,success,target_cpu sched:sched_wakeup_new: trace_fields: comm,pid,prio,success,target_cpu sched:sched_migrate_task: trace_fields: comm,pid,prio,orig_cpu,dest_cpu Committer notes: For another file, in verbose mode: # perf evlist -v --trace-fields sched:sched_switch: type: 2, size: 112, config: 0x10b, { sample_period, sample_freq }: 1, sample_type: IP|TID|TIME|CPU|PERIOD|RAW, disabled: 1, inherit: 1, mmap: 1, comm: 1, task: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1, trace_fields: prev_comm,prev_pid,prev_prio,prev_state,next_comm,next_pid,next_prio # Signed-off-by: Namhyung Kim Cc: Andi Kleen Cc: David Ahern Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Wang Nan Link: http://lkml.kernel.org/r/1452125549-1511-5-git-send-email-namhyung@kernel.org [ Replaced 'trace_fields=' with 'trace_fields: ' to make the output consistent in -v mode ] Signed-off-by: Arnaldo Carvalho de Melo

perf evsel: Disable branch flags/cycles for --callgraph lbr

2015-12-14T15:11:22+00:00

[The kernel patch needed for this is in tip now (b16a5b52eb9 perf/x86: Add option to disable ...) So this user tools patch to make use of it should be merged now] Automatically disable collecting branch flags and cycles with --call-graph lbr. This allows avoiding a bunch of extra MSR reads in the PMI on Skylake. When the kernel doesn't support the new flags they are automatically cleared in the fallback code. v2: Switch to use branch_sample_type instead of sample_type. Adjust description. Fix the fallback logic. Signed-off-by: Andi Kleen Acked-by: Jiri Olsa Link: http://lkml.kernel.org/r/1449879144-29074-1-git-send-email-andi@firstfloor.org Signed-off-by: Arnaldo Carvalho de Melo

perf evsel: Introduce disable() method

2015-12-07T21:12:57+00:00

Adding perf_evsel__disable function to have complement for perf_evsel__enable function. Both will be used in following patch to factor perf_evlist__(enable|disable). Signed-off-by: Jiri Olsa Cc: Adrian Hunter Cc: David Ahern Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1449133606-14429-3-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf evsel: Use event maps directly in perf_evsel__enable

2015-12-07T21:12:57+00:00

All events now share proper cpu and thread maps. There's no need to pass those maps from evlist, it's safe to use evsel maps for enabling event. Signed-off-by: Jiri Olsa Cc: Adrian Hunter Cc: David Ahern Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1449133606-14429-2-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo