Re: [Qemu-devel] [PATCH for-2.5 0/2] trace: decrease overhead of simpletrace and stderr backends

[Stefan Hajnoczi <stefanha@redhat.com>]

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On Wed, Oct 28, 2015 at 07:06:25AM +0100, Paolo Bonzini wrote:
> This patch series makes it faster for simpletrace and stderr backends
> to discard disabled events.  This is done in two ways: patch 1 makes
> the common case of no enabled events faster; patch 2 makes the other
> case less heavy on the data cache by packing the "tracepoint enabled"
> flag and avoiding useless pointer chasing.
> 
> This should decrease the impact of changing the default tracing backend
> to stderr aka log, which Peter suggested could be a problem.
> 
> Paolo
> 
> Paolo Bonzini (2):
>   trace: count number of enabled events
>   trace: track enabled events in a separate array
> 
>  scripts/tracetool/format/events_c.py |  2 +-
>  trace/control-internal.h             | 15 ++++++++++++---
>  trace/control.c                      |  3 +++
>  trace/control.h                      |  2 +-
>  trace/event-internal.h               |  2 --
>  5 files changed, 17 insertions(+), 7 deletions(-)

Thanks, applied to my tracing tree:
https://github.com/stefanha/qemu/commits/tracing

Stefan

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