Re: [PATCH 0/5] [GIT PULL] tracing/splice/ringbuffer: updates for tip

Ingo Molnar
2009-04-29T06:03:57Z

* Steven Rostedt <rostedt@goodmis.org> wrote:

> Ingo,
>
> I was doing a bit of tracing that was stressing the splice code
> and I found lots of badness. Mostly, the second patch is the
> killer, and should most likely go upstream ASAP. The ref counting
> on the splice page is wrong and is never freed!

ah, this probably explains what i reported some time ago: the
ftrace-analyzer OOM hang. I've cherry-picked this into
tracing/urgent as well.

> The rest are fixes to the read side. While debugging the memory
> leak I pulled out my old logdev and used it to monitor what was
> happening inside of ftrace (tracing the tracer). I did not like
> the amount of copying that was happening in splice. This was
> mainly because splice was faster than the writer (and this was
> with function tracer running!). I added some enhancements to make
> the splice code perform a little nicer.
>
> Here's the logdev patch I was using to trace. As well as adding my
> lfcnprint statements (similar to trace_printk).
>
> http://rostedt.homelinux.com/logdev/logdev-0.6.0-2.6.30-rc1.patch
>
> Please pull the latest tip/tracing/ftrace-1 tree, which can be
> found at:
>
> git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git
> tip/tracing/ftrace-1
>
>
> Steven Rostedt (5):
> tracing: convert ftrace_dump spinlocks to raw
> tracing: fix ref count in splice pages
> tracing: only add splice page if entries exist
> tracing: have splice only copy full pages
> ring-buffer: fix printk output
>
> ----
> kernel/trace/ring_buffer.c | 2 +-
> kernel/trace/trace.c | 20 ++++++++++++++------
> 2 files changed, 15 insertions(+), 7 deletions(-)

Pulled, thanks a lot Steve!

Ingo