Commit-ID: 60303ed3f4b9332b9aa9bc17c68bc174e7343e2d Gitweb: http://git.kernel.org/tip/60303ed3f4b9332b9aa9bc17c68bc174e7343e2d Author: David Sharp <dhsh...@google.com> AuthorDate: Thu, 11 Oct 2012 16:27:52 -0700 Committer: Steven Rostedt <rost...@goodmis.org> CommitDate: Fri, 2 Nov 2012 10:21:47 -0400
tracing: Reset ring buffer when changing trace_clocks Because the "tsc" clock isn't in nanoseconds, the ring buffer must be reset when changing clocks so that incomparable timestamps don't end up in the same trace. Tested: Confirmed switching clocks resets the trace buffer. Google-Bug-Id: 6980623 Link: http://lkml.kernel.org/r/1349998076-15495-3-git-send-email-dhsh...@google.com Cc: Masami Hiramatsu <masami.hiramatsu...@hitachi.com> Signed-off-by: David Sharp <dhsh...@google.com> Signed-off-by: Steven Rostedt <rost...@goodmis.org> --- kernel/trace/trace.c | 8 ++++++++ 1 files changed, 8 insertions(+), 0 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 88111b0..6ed6013 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4073,6 +4073,14 @@ static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf, if (max_tr.buffer) ring_buffer_set_clock(max_tr.buffer, trace_clocks[i].func); + /* + * New clock may not be consistent with the previous clock. + * Reset the buffer so that it doesn't have incomparable timestamps. + */ + tracing_reset_online_cpus(&global_trace); + if (max_tr.buffer) + tracing_reset_online_cpus(&max_tr); + mutex_unlock(&trace_types_lock); *fpos += cnt; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
