Greg, I'm testing the backports, and I found that this patch depends on commit 10246fa35d4ffdfe472185d4cbf9c2dfd9a9f023 "tracing: Use flag buffer_disabled for irqsoff tracer" Please add that to 3.10 before applying this fix. Thanks! -- Steve On Sat, 2013-08-03 at 08:49 -0400, Steven Rostedt wrote: > plain text document attachment > (0004-tracing-Fix-reset-of-time-stamps-during-trace_clock-.patch) > From: Alexander Z Lam <azl@xxxxxxxxxx> > > Fixed two issues with changing the timestamp clock with trace_clock: > > - The global buffer was reset on instance clock changes. Change this to pass > the correct per-instance buffer > - ftrace_now() is used to set buf->time_start in tracing_reset_online_cpus(). > This was incorrect because ftrace_now() used the global buffer's clock to > return the current time. Change this to use buffer_ftrace_now() which > returns the current time for the correct per-instance buffer. > > Also removed tracing_reset_current() because it is not used anywhere > > Link: http://lkml.kernel.org/r/1375493777-17261-2-git-send-email-azl@xxxxxxxxxx > > Cc: Vaibhav Nagarnaik <vnagarnaik@xxxxxxxxxx> > Cc: David Sharp <dhsharp@xxxxxxxxxx> > Cc: Alexander Z Lam <lambchop468@xxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx # 3.10 > Signed-off-by: Alexander Z Lam <azl@xxxxxxxxxx> > Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx> > --- > kernel/trace/trace.c | 24 ++++++++++++------------ > 1 file changed, 12 insertions(+), 12 deletions(-) > > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > index 531c9e6..496f94d 100644 > --- a/kernel/trace/trace.c > +++ b/kernel/trace/trace.c > @@ -243,20 +243,25 @@ int filter_current_check_discard(struct ring_buffer *buffer, > } > EXPORT_SYMBOL_GPL(filter_current_check_discard); > > -cycle_t ftrace_now(int cpu) > +cycle_t buffer_ftrace_now(struct trace_buffer *buf, int cpu) > { > u64 ts; > > /* Early boot up does not have a buffer yet */ > - if (!global_trace.trace_buffer.buffer) > + if (!buf->buffer) > return trace_clock_local(); > > - ts = ring_buffer_time_stamp(global_trace.trace_buffer.buffer, cpu); > - ring_buffer_normalize_time_stamp(global_trace.trace_buffer.buffer, cpu, &ts); > + ts = ring_buffer_time_stamp(buf->buffer, cpu); > + ring_buffer_normalize_time_stamp(buf->buffer, cpu, &ts); > > return ts; > } > > +cycle_t ftrace_now(int cpu) > +{ > + return buffer_ftrace_now(&global_trace.trace_buffer, cpu); > +} > + > /** > * tracing_is_enabled - Show if global_trace has been disabled > * > @@ -1211,7 +1216,7 @@ void tracing_reset_online_cpus(struct trace_buffer *buf) > /* Make sure all commits have finished */ > synchronize_sched(); > > - buf->time_start = ftrace_now(buf->cpu); > + buf->time_start = buffer_ftrace_now(buf, buf->cpu); > > for_each_online_cpu(cpu) > ring_buffer_reset_cpu(buffer, cpu); > @@ -1219,11 +1224,6 @@ void tracing_reset_online_cpus(struct trace_buffer *buf) > ring_buffer_record_enable(buffer); > } > > -void tracing_reset_current(int cpu) > -{ > - tracing_reset(&global_trace.trace_buffer, cpu); > -} > - > /* Must have trace_types_lock held */ > void tracing_reset_all_online_cpus(void) > { > @@ -4634,12 +4634,12 @@ static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf, > * 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.trace_buffer); > + tracing_reset_online_cpus(&tr->trace_buffer); > > #ifdef CONFIG_TRACER_MAX_TRACE > if (tr->flags & TRACE_ARRAY_FL_GLOBAL && tr->max_buffer.buffer) > ring_buffer_set_clock(tr->max_buffer.buffer, trace_clocks[i].func); > - tracing_reset_online_cpus(&global_trace.max_buffer); > + tracing_reset_online_cpus(&tr->max_buffer); > #endif > > mutex_unlock(&trace_types_lock); -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html