On 2016/11/15 12:57, Alexei Starovoitov wrote:
On Mon, Nov 14, 2016 at 8:05 PM, Wang Nan <[email protected]> wrote:
This is version 2 of perf builtin clang patch series. Compare to v1,
add an exciting feature: jit compiling perf hook functions. This
features allows script writer report result through BPF map in a
customized way.
looks great.
SEC("perfhook:record_start")
void record_start(void *ctx)
{
int perf_pid = getpid(), key = G_perf_pid;
printf("Start count, perfpid=%d\n", perf_pid);
jit_helper__map_update_elem(ctx, &GVALS, &key, &perf_pid, 0);
the name, I think, is too verbose.
Why not to keep them as bpf_map_update_elem
even for user space programs?
I can make it shorter by give it a better name or use a wrapper like
BPF_MAP(update_elem)
but the only thing I can't do is to make perfhook and in-kernel script
use a uniform name for these bpf_map functions, because
bpf_map_update_elem is already defined:
"static long (*bpf_map_update_elem)(void *, void *, void *, unsigned
long) = (void *)2;\n"
SEC("perfhook:record_end")
void record_end(void *ctx)
{
u64 key = -1, value;
while (!jit_helper__map_get_next_key(ctx, &syscall_counter, &key,
&key)) {
jit_helper__map_lookup_elem(ctx, &syscall_counter, &key,
&value);
printf("syscall %ld\tcount: %ld\n", (long)key, (long)value);
this loop will be less verbose as well.
