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authorWang Nan <wangnan0@huawei.com>2016-02-22 09:10:37 +0000
committerArnaldo Carvalho de Melo <acme@redhat.com>2016-02-22 14:37:21 -0300
commit03e0a7df3efd959e40cd7ff40b1fabddc234ec5a (patch)
tree1ea26255f2094fa42429cce70f0cf22b9038d189 /tools/perf/util/bpf-loader.c
parent95088a591e197610bd03f4059f5fdbe9e376425b (diff)
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perf tools: Introduce bpf-output event
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 <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 ... Signed-off-by: Wang Nan <wangnan0@huawei.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Cody P Schafer <dev@codyps.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jeremie Galarneau <jeremie.galarneau@efficios.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kirill Smelkov <kirr@nexedi.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Zefan Li <lizefan@huawei.com> 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 <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/bpf-loader.c')
-rw-r--r--tools/perf/util/bpf-loader.c5
1 files changed, 2 insertions, 3 deletions
diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index 44824e3eeaed..0967ce601931 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -1331,13 +1331,12 @@ apply_config_evsel_for_key(const char *name, int map_fd, void *pkey,
return -BPF_LOADER_ERRNO__OBJCONF_MAP_EVTINH;
}
+ if (perf_evsel__is_bpf_output(evsel))
+ check_pass = true;
if (attr->type == PERF_TYPE_RAW)
check_pass = true;
if (attr->type == PERF_TYPE_HARDWARE)
check_pass = true;
- if (attr->type == PERF_TYPE_SOFTWARE &&
- attr->config == PERF_COUNT_SW_BPF_OUTPUT)
- check_pass = true;
if (!check_pass) {
pr_debug("ERROR: Event type is wrong for map %s\n", name);
return -BPF_LOADER_ERRNO__OBJCONF_MAP_EVTTYPE;