Re: [PATCH] Fix race in ring_buffer_consume(): Replace ring_buffer_consume and ring_buffer_peek with ring_buffer_get_event

From: Indan Zupancic
Date: Thu Jan 01 2009 - 00:10:37 EST


On Mon, December 29, 2008 13:24, Ingo Molnar wrote:
>
> * Indan Zupancic <indan@xxxxxx> wrote:
>
>> Original mail was mangled, patch resent via git.
>>
>> Signed-off-by: Indan Zupancic <indan@xxxxxx>
>> ---
>> include/linux/ring_buffer.h | 4 +---
>> kernel/trace/ring_buffer.c | 39
>> ++++++++-------------------------------
>> kernel/trace/trace.c | 15 ++++++++-------
>> kernel/trace/trace_selftest.c | 2 +-
>> 4 files changed, 18 insertions(+), 42 deletions(-)
>
> there's been a number of updates here - could you please do a patch
> against tip/master:
>
> http://people.redhat.com/mingo/tip.git/README

Thanks for that readme, now I discovered git remote, which is not
mentioned often enough for some reason.

A lot changed indeed, most importantly the race that I hit is
fixed in tip by improved locking. Replace ring_buffer_consume()
and ring_buffer_peek() with ring_buffer_get_event() or not is
just a matter of taste now. Are you still interested in such a
patch?

(34 EXPORT_SYMBOL_GPLs in ring_buffer.c seems a bit excessive though.)

Greetings,

Indan


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