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Re: [PATCH, RFC] Fix build problems related to profile-directed optimization

From
Junio C Hamano <gitster@pobox.com>
Date
Feb 3, 2012, 00:58 UTC
Message-ID
<7vvcnou40u.fsf@alter.siamese.dyndns.org>
In-Reply-To
<20120202201226.GA1032@thunk.org>
Ted Ts'o <tytso@mit.edu> writes:
Show 9 quoted lines
> ...
> At least in theory, it should be possible to have something which
> supports both PROFILE_GEN/PROFILE_USE as well as a combined
> PROFILE_BUILD.
>
> The hard part is that PROFILE_BUILD requires a multi-pass process; you
> need to build with one set of CFLAGS, then run the sample workload to
> get the data for your feedback directed optimizations, and then re-run
> the build with another set of CFLAGS.

Yeah, I can see how that forces us to some kludgy solution, but I tend to agree that the separation between GEN/USE is a good thing.

> I think what we could to check
> for PROFILE_BUILD, and if it is set, do the first PROFILE_GEN / make
> test commands as part of the top-level Makefile's all: rule, and then
> do the normal build after that.

Yeah, something like that would emulate the "make profile-all" well enough for people not to notice the change while giving us the flexibility of GEN/USE separation. I kinda like it.

Thanks.
Previous: Ted Ts'oNext: Ted Ts'o
Message 5 of 18 in “Fix build problems related to profile-directed optimization”
  1. Fix build problems related to profile-directed optimizationTheodore Ts'o, Feb 2, 2012
  2. Junio C HamanoFeb 2, 2012
  3. Ted Ts'oFeb 2, 2012
  4. Ted Ts'oFeb 2, 2012
  5. Junio C HamanoFeb 3, 2012
  6. Ted Ts'oFeb 3, 2012
  7. Junio C HamanoFeb 3, 2012
  8. Theodore TsoFeb 3, 2012
  9. Junio C HamanoFeb 3, 2012
  10. Fix build problems related to profile-directed optimizationTheodore Ts'o, Feb 6, 2012
  11. Jeff KingFeb 6, 2012
  12. Ted Ts'oFeb 6, 2012
  13. Fix build problems related to profile-directed optimizationTheodore Ts'o, Feb 6, 2012
  14. Ted Ts'oFeb 8, 2012
  15. Junio C HamanoFeb 9, 2012
  16. Johannes SixtFeb 9, 2012
  17. Junio C HamanoFeb 9, 2012
  18. Andi KleenFeb 3, 2012

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