On 12/07/2017 09:01 PM, Masami Hiramatsu wrote:

On Thu, 7 Dec 2017 10:34:51 -0600
Paul Clarke [off-list ref] wrote:

quoted

On 12/07/2017 01:20 AM, Masami Hiramatsu wrote:

quoted

Cut off the version suffix (e.g. @GLIBC_2.2.5 etc.) from
automatic generated event name. This fixes wildcard event
adding like below case;

  =====
  # perf probe -x /lib64/libc-2.25.so malloc*
  Internal error: "malloc_get_state@GLIBC_2" is wrong event name.
    Error: Failed to add events.
  =====

This failure was caused by a versioned suffix symbol.
With this fix, perf probe automatically cuts the
suffix after @ as below.

  =====
  # ./perf probe -x /lib64/libc-2.25.so malloc*
  Added new events:
    probe_libc:malloc_printerr (on malloc* in /usr/lib64/libc-2.25.so)
    probe_libc:malloc_consolidate (on malloc* in /usr/lib64/libc-2.25.so)
    probe_libc:malloc_check (on malloc* in /usr/lib64/libc-2.25.so)
    probe_libc:malloc_hook_ini (on malloc* in /usr/lib64/libc-2.25.so)
    probe_libc:malloc    (on malloc* in /usr/lib64/libc-2.25.so)
    probe_libc:malloc_trim (on malloc* in /usr/lib64/libc-2.25.so)
    probe_libc:malloc_usable_size (on malloc* in /usr/lib64/libc-2.25.so)
    probe_libc:malloc_stats (on malloc* in /usr/lib64/libc-2.25.so)
    probe_libc:malloc_info (on malloc* in /usr/lib64/libc-2.25.so)
    probe_libc:mallochook (on malloc* in /usr/lib64/libc-2.25.so)
    probe_libc:malloc_get_state (on malloc* in /usr/lib64/libc-2.25.so)
    probe_libc:malloc_set_state (on malloc* in /usr/lib64/libc-2.25.so)

  You can now use it in all perf tools, such as:

	  perf record -e probe_libc:malloc_set_state -aR sleep 1

  =====

I think this will still fall over for a case where there are multiple versions of the same base symbol, like:

$ nm /lib64/libc.so.6 | egrep ' sched_getaffinity'
0000000000134430 T sched_getaffinity@GLIBC_2.3.3
00000000000dcf00 T sched_getaffinity@@GLIBC_2.3.4

No, in that case perf probe adds number suffix (_1, _2...) for new events :)

This feature (number suffix) is anyway required for the case that inlined
function is spreaded in multiple places. I think this is natural for perf probe.

I can live with that.

Is the versioning tag retained for display with "perf probe -l" display, so the probe points can be distinguished?

In other words, will one see:
# perf probe -l
  probe_libc:sched_getaffinity (on sched_getaffinity@GLIBC_2.3.3 in /usr/lib64/libc-2.17.so)
  probe_libc:sched_getaffinity_1 (on sched_getaffinity@@GLIBC_2.3.4 in /usr/lib64/libc-2.17.so)
or
# perf probe -l
  probe_libc:sched_getaffinity (on sched_getaffinity in /usr/lib64/libc-2.17.so)
  probe_libc:sched_getaffinity_1 (on sched_getaffinity in /usr/lib64/libc-2.17.so)

PC