This patch adds the final step for BPF map configuration. A new syntax
is appended into parser so user can config BPF objects through '/' '/'
enclosed config terms.
After this patch, following syntax is available:
# perf record -e ./test_bpf_map_1.c/map:channel.value=10/ ...
It would takes effect after appling following commits.
Test result:
# cat ./test_bpf_map_1.c
/************************ BEGIN **************************/
#include <uapi/linux/bpf.h>
#define SEC(NAME) __attribute__((section(NAME), used))
struct bpf_map_def {
unsigned int type;
unsigned int key_size;
unsigned int value_size;
unsigned int max_entries;
};
static void *(*map_lookup_elem)(struct bpf_map_def *, void *) =
(void *)BPF_FUNC_map_lookup_elem;
static int (*trace_printk)(const char *fmt, int fmt_size, ...) =
(void *)BPF_FUNC_trace_printk;
struct bpf_map_def SEC("maps") channel = {
.type = BPF_MAP_TYPE_ARRAY,
.key_size = sizeof(int),
.value_size = sizeof(int),
.max_entries = 1,
};
SEC("func=sys_nanosleep")
int func(void *ctx)
{
int key = 0;
char fmt[] = "%d\n";
int *pval = map_lookup_elem(&channel, &key);
if (!pval)
return 0;
trace_printk(fmt, sizeof(fmt), *pval);
return 0;
}
char _license[] SEC("license") = "GPL";
int _version SEC("version") = LINUX_VERSION_CODE;
/************************* END ***************************/
- Normal case:
# ./perf record -e './test_bpf_map_1.c/map:channel.value=10/' usleep 10
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.012 MB perf.data ]
- Error case:
# ./perf record -e './test_bpf_map_1.c/map:channel.value/' usleep 10
event syntax error: '..ps:channel:value/'
\___ Config value not set (missing '=')
Hint: Valid config term:
map:[<arraymap>]:value=[value]
(add -v to see detail)
Run 'perf list' for a list of valid events
Usage: perf record [<options>] [<command>]
or: perf record [<options>] -- <command> [<options>]
-e, --event <event> event selector. use 'perf list' to list available events
# ./perf record -e './test_bpf_map_1.c/xmap:channel.value=10/' usleep 10
event syntax error: '..pf_map_1.c/xmap:channel.value=10/'
\___ Invalid object config option
[SNIP]
# ./perf record -e './test_bpf_map_1.c/map:xchannel.value=10/' usleep 10
event syntax error: '..p_1.c/map:xchannel.value=10/'
\___ Target map not exist
[SNIP]
# ./perf record -e './test_bpf_map_1.c/map:channel.xvalue=10/' usleep 10
event syntax error: '..ps:channel.xvalue=10/'
\___ Invalid object map config option
[SNIP]
# ./perf record -e './test_bpf_map_1.c/map:channel.value=x10/' usleep 10
event syntax error: '..nnel.value=x10/'
\___ Incorrect value type for map
[SNIP]
Change BPF_MAP_TYPE_ARRAY to '1' in test_bpf_map_1.c:
# ./perf record -e './test_bpf_map_1.c/map:channel.value=10/' usleep 10
event syntax error: '..ps:channel.value=10/'
\___ Can't use this config term to this type of map
Hint: Valid config term:
map:[<arraymap>].value=[value]
(add -v to see detail)
Signed-off-by: Wang Nan <wangnan0@huawei.com>
[for parser part]
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.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: 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/1456132275-98875-5-git-send-email-wangnan0@huawei.com
Signed-off-by: He Kuang <hekuang@huawei.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
a34f3be70c