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Re: [PATCH] Reduce performance penalty for turned off traces

From
Stefan Beller <sbeller@google.com>
Date
Nov 15, 2017, 19:14 UTC
Message-ID
<CAGZ79kb4Eo0AC4Z42_ks5_+Pcy4DrDCufNb=5J=g8L6pMnHd7A@mail.gmail.com>
In-Reply-To
<20171112141737.nmnsygm4wrhtkqwb@sigill.intra.peff.net>
On Sun, Nov 12, 2017 at 6:17 AM, Jeff King <peff@peff.net> wrote:
Show 7 quoted lines
> On Sat, Nov 11, 2017 at 07:28:58PM +0000, gennady.kupava@gmail.com wrote:
>
>> From: Gennady Kupava <gkupava@bloomberg.net>
>>
>> Signed-off-by: Gennady Kupava <gkupava@bloomberg.net>
>
> Thanks, and welcome to the list.
Welcome to the list!
> I did manually disable HAVE_VARIADIC_MACROS and confirmed that the
> result builds and passes the test suite (though I suspect that GIT_TRACE
> is not well exercised by the suite).

GIT_TRACE is exercised in the test suite (though I am not sure if it counts as well-exercised) in t7406-submodule-update.sh for example, which uses GIT_TRACE to obtain information about thread parallelism used by Git, as that is not observable otherwise, if we assume that performance tests in the standard test suite are not feasible.

Show 7 quoted lines
> I tried timing a simple loop like:
> ....
> Without your patch, the times for GIT_TRACE=1 and GIT_TRACE=0 are about
> 500ms and 9ms respectively.
>
> After your patch, the GIT_TRACE=1 time remains the same but GIT_TRACE=0
> drops to 1ms.
So does that mean we can use a lot more tracing now?

Thanks, Stefan

Previous: Jeff KingNext: Jeff King
Message 5 of 20 in “Reduce performance penalty for turned off traces”
  1. Reduce performance penalty for turned off tracesgennady.kupava@gmail.com, Nov 11, 2017
  2. Jeff KingNov 12, 2017
  3. Gennady KupavaNov 12, 2017
  4. Jeff KingNov 17, 2017
  5. Stefan BellerNov 15, 2017
  6. Jeff KingNov 17, 2017
  7. 1/2 Simplify tracing code by removing trace key normalization conceptgennady.kupava@gmail.com, Nov 19, 2017
  8. 2/2 Reduce performance cost of the trace if trace category is disabledgennady.kupava@gmail.com, Nov 19, 2017
  9. Johannes SixtNov 19, 2017
  10. Gennady KupavaNov 19, 2017
  11. Junio C HamanoNov 19, 2017
  12. Gennady KupavaNov 19, 2017
  13. Junio C HamanoNov 20, 2017
  14. Junio C HamanoNov 20, 2017
  15. 1/2 trace: remove trace key normalizationgennady.kupava@gmail.com, Nov 26, 2017
  16. 2/2 trace: improve performance while category is disabledgennady.kupava@gmail.com, Nov 26, 2017
  17. Junio C HamanoNov 27, 2017
  18. Junio C HamanoNov 27, 2017
  19. Junio C HamanoNov 27, 2017
  20. Gennady KupavaNov 27, 2017

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