Messages in this thread | | | Date | Thu, 13 Nov 2008 09:40:40 +0100 | From | Ingo Molnar <> | Subject | Re: [PATCH v2 1/1] ftrace: do not update max buffer with no users |
| |
* Steven Rostedt <rostedt@goodmis.org> wrote:
> Impact: only use max latency buffer when a user is configured > > Pekka reported a bug with the resizing of the buffers when only the > MMIO tracer was configured. The issue was, to save memory, the max > latency trace buffer was only initialized if a tracer that uses it > is configured in. > > What happened was that the max latency buffer was never initialized > when only the MMIO tracer was configurued. The MMIO tracer does not > use the max tracer, which kept it from being initialized. But the > resize code still tried to resize the max latency buffers, but > because they were never allocated, the resize code was passed a NULL > pointer. > > This patch checks if the max tracer is NULL before resizing it. It > also hides the modification functions of the max tracer behind the > TRACER_MAX_TRACE config. > > Reported-by: Pekka Paalanen <pq@iki.fi> > Signed-off-by: Steven Rostedt <srostedt@redhat.com> > --- > kernel/trace/trace.c | 171 ++++++++++++++++++++++++++------------------------ > 1 files changed, 88 insertions(+), 83 deletions(-)
This is _way_ too much churn for .28, we need a much simpler solution.
Ingo
| |