From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Wang Nan <wangnan0@huawei.com>
Cc: "Alexei Starovoitov" <ast@kernel.org>,
"Arnaldo Carvalho de Melo" <acme@redhat.com>,
"Brendan Gregg" <brendan.d.gregg@gmail.com>,
"Adrian Hunter" <adrian.hunter@intel.com>,
"Cody P Schafer" <dev@codyps.com>,
"David S. Miller" <davem@davemloft.net>,
"He Kuang" <hekuang@huawei.com>,
"Jérémie Galarneau" <jeremie.galarneau@efficios.com>,
"Jiri Olsa" <jolsa@kernel.org>,
"Kirill Smelkov" <kirr@nexedi.com>,
"Li Zefan" <lizefan@huawei.com>,
"Masami Hiramatsu" <masami.hiramatsu.pt@hitachi.com>,
"Namhyung Kim" <namhyung@kernel.org>,
"Peter Zijlstra" <peterz@infradead.org>,
pi3orama@163.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 10/48] perf tools: Introduce bpf-output event
Date: Tue, 23 Feb 2016 14:45:39 -0300 [thread overview]
Message-ID: <20160223174539.GG15284@kernel.org> (raw)
In-Reply-To: <1456132275-98875-11-git-send-email-wangnan0@huawei.com>
Em Mon, Feb 22, 2016 at 09:10:37AM +0000, Wang Nan escreveu:
> Commit a43eec304259a6c637f4014a6d4767159b6a3aa3 (bpf: introduce
> bpf_perf_event_output() helper) add a helper to enable BPF program
> output data to perf ring buffer through a new type of perf event
> PERF_COUNT_SW_BPF_OUTPUT. This patch enable perf to create perf
> event of that type. Now perf user can use 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 <uapi/linux/bpf.h>
> 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 ...
So, there is something strange here:
if (unlikely(event->oncpu != smp_processor_id()))
return -EOPNOTSUPP;
This is where I am hitting, with:
[acme@jouet linux]$ uname -r
4.5.0-rc4
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);
And then:
[root@jouet bpf]# tail /sys/kernel/debug/tracing/trace
perf-13040 [003] d... 12062.807729: : Error: failed to output: -95
perf-13040 [003] d... 12062.807731: : Error: failed to output: -95
perf-13040 [003] d... 12062.807732: : Error: failed to output: -95
perf-13040 [003] d... 12062.807735: : Error: failed to output: -95
perf-13040 [003] d... 12062.807737: : Error: failed to output: -95
perf-13040 [003] d... 12062.807744: : Error: failed to output: -95
gnome-terminal--3091 [001] d... 12062.807773: : Error: failed to output: -95
gnome-terminal--3091 [001] d... 12062.807784: : Error: failed to output: -95
gmain-2830 [002] d... 12062.811791: : Error: failed to output: -95
gmain-2830 [002] d... 12062.811810: : Error: failed to output: -95
[root@jouet bpf]#
Ideas? AFK for a while, will continue investigating.
This already was submitted to Ingo, BTW.
I used, as in the changeset comment tests:
perf record -a -e bpf-output/no-inherit,name=evt/ -e ./test_bpf_output.c/map:channel.event=evt/ ls /
And perf script told me:
[root@jouet bpf]# perf script | tail
perf 13040 [003] 12062.708337: evt: ffffffff81234eb1 sys_write (/lib/modules/4.5.0-rc4/build/vmlinux)
perf 13040 [003] 12062.708339: evt: ffffffff81234eb1 sys_write (/lib/modules/4.5.0-rc4/build/vmlinux)
perf 13040 [003] 12062.708340: evt: ffffffff81234eb1 sys_write (/lib/modules/4.5.0-rc4/build/vmlinux)
perf 13040 [003] 12062.708341: evt: ffffffff81234eb1 sys_write (/lib/modules/4.5.0-rc4/build/vmlinux)
perf 13040 [003] 12062.708343: evt: ffffffff81234eb1 sys_write (/lib/modules/4.5.0-rc4/build/vmlinux)
perf 13040 [003] 12062.708344: evt: ffffffff81234eb1 sys_write (/lib/modules/4.5.0-rc4/build/vmlinux)
perf 13040 [003] 12062.708346: evt: ffffffff81234eb1 sys_write (/lib/modules/4.5.0-rc4/build/vmlinux)
perf 13040 [003] 12062.708347: evt: ffffffff81234eb1 sys_write (/lib/modules/4.5.0-rc4/build/vmlinux)
perf 13040 [003] 12062.708348: evt: ffffffff81234eb1 sys_write (/lib/modules/4.5.0-rc4/build/vmlinux)
perf 13040 [003] 12062.708350: evt: ffffffff81234eb1 sys_write (/lib/modules/4.5.0-rc4/build/vmlinux)
[root@jouet bpf]#
Wonder where that /lib/modules/4.5.0-rc4/build/vmlinux came from...
[root@jouet bpf]# perf script | cut -d'(' -f2 | sort | uniq -c
1141 /lib/modules/4.5.0-rc4/build/vmlinux)
- Arnaldo
next prev parent reply other threads:[~2016-02-23 17:45 UTC|newest]
Thread overview: 76+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-22 9:10 [PATCH 00/48] perf tools: Bugfix, BPF improvements and overwrite ring buffer support Wang Nan
2016-02-22 9:10 ` [PATCH 01/48] perf tools: Record text offset in dso to calculate objdump address Wang Nan
2016-02-22 9:10 ` [PATCH 02/48] perf tools: Adjust symbol for shared objects Wang Nan
2016-02-22 9:10 ` [PATCH 03/48] perf bpf: Add API to set values to map entries in a bpf object Wang Nan
2016-02-25 5:39 ` [tip:perf/core] " tip-bot for Wang Nan
2016-02-22 9:10 ` [PATCH 04/48] perf tools: Enable BPF object configure syntax Wang Nan
2016-02-25 5:39 ` [tip:perf/core] " tip-bot for Wang Nan
2016-02-22 9:10 ` [PATCH 05/48] perf record: Apply config to BPF objects before recording Wang Nan
2016-02-25 5:39 ` [tip:perf/core] " tip-bot for Wang Nan
2016-02-22 9:10 ` [PATCH 06/48] perf tools: Enable passing event to BPF object Wang Nan
2016-02-25 5:40 ` [tip:perf/core] " tip-bot for Wang Nan
2016-02-22 9:10 ` [PATCH 07/48] perf tools: Support setting different slots in a BPF map separately Wang Nan
2016-02-25 5:40 ` [tip:perf/core] " tip-bot for Wang Nan
2016-02-22 9:10 ` [PATCH 08/48] perf tools: Enable indices setting syntax for BPF map Wang Nan
2016-02-25 5:40 ` [tip:perf/core] " tip-bot for Wang Nan
2016-02-22 9:10 ` [PATCH 09/48] perf tools: Pass tracepoint options to BPF script Wang Nan
2016-02-25 5:41 ` [tip:perf/core] perf tools: Apply tracepoint event definition " tip-bot for Wang Nan
2016-02-22 9:10 ` [PATCH 10/48] perf tools: Introduce bpf-output event Wang Nan
2016-02-23 17:45 ` Arnaldo Carvalho de Melo [this message]
2016-02-24 1:58 ` Wangnan (F)
2016-02-24 2:04 ` Wangnan (F)
2016-02-24 4:03 ` Wangnan (F)
2016-02-24 5:03 ` Wangnan (F)
2016-02-24 13:36 ` Arnaldo Carvalho de Melo
2016-02-25 5:41 ` [tip:perf/core] " tip-bot for Wang Nan
2016-02-22 9:10 ` [PATCH 11/48] perf data: Support converting data from bpf_perf_event_output() Wang Nan
2016-02-23 16:14 ` Arnaldo Carvalho de Melo
2016-02-23 17:23 ` Jiri Olsa
2016-02-23 17:24 ` Jiri Olsa
2016-02-23 19:22 ` Jiri Olsa
2016-02-22 9:10 ` [PATCH 12/48] perf data: Explicitly set byte order for integer types Wang Nan
2016-02-22 9:10 ` [PATCH 13/48] perf core: Introduce new ioctl options to pause and resume ring buffer Wang Nan
2016-02-22 9:10 ` [PATCH 14/48] perf core: Set event's default overflow_handler Wang Nan
2016-02-22 9:10 ` [PATCH 15/48] perf core: Prepare writing into ring buffer from end Wang Nan
2016-02-22 9:10 ` [PATCH 16/48] perf core: Add backward attribute to perf event Wang Nan
2016-02-24 13:08 ` Jiri Olsa
2016-02-24 13:21 ` Jiri Olsa
2016-02-22 9:10 ` [PATCH 17/48] perf core: Reduce perf event output overhead by new overflow handler Wang Nan
2016-02-22 9:10 ` [PATCH 18/48] perf tools: Only validate is_pos for tracking evsels Wang Nan
2016-02-24 14:21 ` Jiri Olsa
2016-02-22 9:10 ` [PATCH 19/48] perf tools: Print write_backward value in perf_event_attr__fprintf Wang Nan
2016-02-22 9:10 ` [PATCH 20/48] perf tools: Make ordered_events reusable Wang Nan
2016-02-24 14:18 ` Jiri Olsa
2016-02-22 9:10 ` [PATCH 21/48] perf record: Extract synthesize code to record__synthesize() Wang Nan
2016-02-24 14:29 ` Jiri Olsa
2016-02-22 9:10 ` [PATCH 22/48] perf tools: Add perf_data_file__switch() helper Wang Nan
2016-02-24 14:34 ` Jiri Olsa
2016-02-22 9:10 ` [PATCH 23/48] perf record: Turns auxtrace_snapshot_enable into 3 states Wang Nan
2016-02-24 14:43 ` Jiri Olsa
2016-02-22 9:10 ` [PATCH 24/48] perf record: Introduce record__finish_output() to finish a perf.data Wang Nan
2016-02-22 9:10 ` [PATCH 25/48] perf record: Add '--timestamp-filename' option to append timestamp to output filename Wang Nan
2016-02-22 9:10 ` [PATCH 26/48] perf record: Split output into multiple files via '--switch-output' Wang Nan
2016-02-22 9:10 ` [PATCH 27/48] perf record: Force enable --timestamp-filename when --switch-output is provided Wang Nan
2016-02-22 9:10 ` [PATCH 28/48] perf record: Disable buildid cache options by default in switch output mode Wang Nan
2016-02-22 9:10 ` [PATCH 29/48] perf record: Re-synthesize tracking events after output switching Wang Nan
2016-02-24 14:57 ` Jiri Olsa
2016-02-22 9:10 ` [PATCH 30/48] perf record: Generate tracking events for process forked by perf Wang Nan
2016-02-24 15:01 ` Jiri Olsa
2016-02-22 9:10 ` [PATCH 31/48] perf record: Ensure return non-zero rc when mmap fail Wang Nan
2016-02-22 9:10 ` [PATCH 32/48] perf record: Prevent reading invalid data in record__mmap_read Wang Nan
2016-02-22 9:11 ` [PATCH 33/48] perf tools: Add evlist channel helpers Wang Nan
2016-02-22 9:11 ` [PATCH 34/48] perf tools: Automatically add new channel according to evlist Wang Nan
2016-02-22 9:11 ` [PATCH 35/48] perf tools: Operate multiple channels Wang Nan
2016-02-22 9:11 ` [PATCH 36/48] perf tools: Squash overwrite setting into channel Wang Nan
2016-02-22 9:11 ` [PATCH 37/48] perf record: Don't read from and poll overwrite channel Wang Nan
2016-02-22 9:11 ` [PATCH 38/48] perf record: Don't poll on " Wang Nan
2016-02-22 9:11 ` [PATCH 39/48] perf tools: Detect avalibility of write_backward Wang Nan
2016-02-22 9:11 ` [PATCH 40/48] perf tools: Enable overwrite settings Wang Nan
2016-02-22 9:11 ` [PATCH 41/48] perf tools: Set write_backward attribut bit for overwrite events Wang Nan
2016-02-22 9:11 ` [PATCH 42/48] perf tools: Record fd into perf_mmap Wang Nan
2016-02-22 9:11 ` [PATCH 43/48] perf tools: Add API to pause a channel Wang Nan
2016-02-22 9:11 ` [PATCH 44/48] perf record: Toggle overwrite ring buffer for reading Wang Nan
2016-02-22 9:11 ` [PATCH 45/48] perf record: Rename variable to make code clear Wang Nan
2016-02-22 9:11 ` [PATCH 46/48] perf record: Read from backward ring buffer Wang Nan
2016-02-22 9:11 ` [PATCH 47/48] perf record: Allow generate tracking events at the end of output Wang Nan
2016-02-22 9:11 ` [PATCH 48/48] perf tools: Don't warn about out of order event if write_backward is used Wang Nan
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