tree 84655a5404fb290f8492f3f953f9e61007f7c3e2
parent 32520b2c695b23221751eb09360a6a3dd3105b52
author Oleg Nesterov <oleg@redhat.com> 1365860209 +0200
committer Oleg Nesterov <oleg@redhat.com> 1366040392 +0200

uprobes/perf: Avoid perf_trace_buf_prepare/submit if ->perf_events is empty

perf_trace_buf_prepare() + perf_trace_buf_submit() make no sense
if this task/CPU has no active counters. Change uprobe_perf_print()
to return if hlist_empty(call->perf_events).

Note: this is not uprobe-specific, we can change other users too.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>