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From: Jiri Olsa <jolsa@redhat.com>
To: Ingo Molnar <mingo@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>,
	David Ahern <dsahern@gmail.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Thomas Gleixner <tglx@linutronix.de>,
	Andrew Morton <akpm@linux-foundation.org>,
	Namhyung Kim <namhyung@gmail.com>
Subject: Re: [PATCH] perf auto-dep: Speed up feature tests by building them in parallel
Date: Wed, 2 Oct 2013 11:26:08 +0200	[thread overview]
Message-ID: <20131002092608.GA10099@krava.brq.redhat.com> (raw)
In-Reply-To: <20130930164210.GA22342@gmail.com>

On Mon, Sep 30, 2013 at 06:42:10PM +0200, Ingo Molnar wrote:
> 
> This series (with combo patch attached) implements (much) faster 
> perf-tools feature-auto-detection.
> 
> I used 3 tricks to implement feature auto-dependencies and to speed up 
> feature detection:
> 
>   - standalone Makefile in config/feature-checks/ built in parallel
> 
>   - split-out standalone .c files in config/feature-checks/*.c
> 
>   - used GCC's auto-dependency generation feature (-MD) to track the
>     effects of system library addition/removal.
> 
> Before the changes a fully cached re-build of an already built tree took 
> 2.6 second:
> 
>     $ perf stat --null --sync --repeat 3 -a make Makefile
> 
>        2.669467209 seconds time elapsed                                          ( +-  0.07% )
> 
> After the changes it takes only 0.6 seconds:
> 
>        0.599161560 seconds time elapsed                                          ( +-  0.25% )

nice!

> 
> So the empty build got 4.4x faster.
> 

SNIP

>  ifdef NO_DEMANGLE
>    CFLAGS += -DNO_DEMANGLE
>  else
> -  ifdef HAVE_CPLUS_DEMANGLE
> +  ifdef HAVE_CPLUS_DEMANGLE_SUPPORT
>      EXTLIBS += -liberty
> -    CFLAGS += -DHAVE_CPLUS_DEMANGLE
> +    CFLAGS += -DHAVE_CPLUS_DEMANGLE_SUPPORT
>    else
>      FLAGS_BFD=$(CFLAGS) $(LDFLAGS) $(EXTLIBS) -DPACKAGE='perf' -lbfd
> -    has_bfd := $(call try-cc,$(SOURCE_BFD),$(FLAGS_BFD),libbfd)
> -    ifeq ($(has_bfd),y)
> +    ifeq ($(feature-libbfd), 1)
>        EXTLIBS += -lbfd
>      else
>        FLAGS_BFD_IBERTY=$(FLAGS_BFD) -liberty
> @@ -388,7 +410,7 @@ else
>            has_cplus_demangle := $(call try-cc,$(SOURCE_CPLUS_DEMANGLE),$(FLAGS_CPLUS_DEMANGLE),demangle)
>            ifeq ($(has_cplus_demangle),y)
>              EXTLIBS += -liberty
> -            CFLAGS += -DHAVE_CPLUS_DEMANGLE
> +            CFLAGS += -DHAVE_CPLUS_DEMANGLE_SUPPORT
>            else
>              msg := $(warning No bfd.h/libbfd found, install binutils-dev[el]/zlib-static to gain symbol demangling)
>              CFLAGS += -DNO_DEMANGLE
> @@ -400,30 +422,29 @@ else
>  endif

Why not add tests for has_bfd_iberty/has_bfd_iberty_z/has_cplus_demangle?

We could remove the config/feature-tests.mak completely
and other cleanup like remove try-cc.

jirka

  parent reply	other threads:[~2013-10-02  9:26 UTC|newest]

Thread overview: 60+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-09-12 13:38 [GIT PULL] perf fixes Ingo Molnar
2013-09-12 18:03 ` Linus Torvalds
2013-09-12 18:10   ` Linus Torvalds
2013-09-12 18:43     ` Arnaldo Carvalho de Melo
2013-09-12 19:12       ` Arnaldo Carvalho de Melo
2013-09-12 19:13         ` Linus Torvalds
2013-09-12 19:55       ` Ingo Molnar
2013-09-12 19:58       ` David Ahern
2013-09-12 20:02         ` Arnaldo Carvalho de Melo
2013-09-12 20:31           ` Ingo Molnar
2013-09-12 20:43             ` Ingo Molnar
2013-09-15  9:10               ` [PATCH] perf test-hack: Split out feature tests to cache them and to build them in parallel Ingo Molnar
2013-09-30 16:42                 ` [PATCH] perf auto-dep: Speed up feature tests by building " Ingo Molnar
2013-09-30 17:12                   ` Arnaldo Carvalho de Melo
2013-09-30 17:27                     ` Arnaldo Carvalho de Melo
2013-09-30 17:30                       ` Arnaldo Carvalho de Melo
2013-09-30 17:36                         ` Arnaldo Carvalho de Melo
2013-09-30 17:39                           ` Arnaldo Carvalho de Melo
2013-09-30 17:46                             ` Arnaldo Carvalho de Melo
2013-09-30 18:02                               ` Arnaldo Carvalho de Melo
2013-09-30 19:15                                 ` Ingo Molnar
2013-09-30 19:09                         ` Ingo Molnar
2013-09-30 17:34                     ` Linus Torvalds
2013-09-30 17:53                       ` Arnaldo Carvalho de Melo
2013-09-30 19:04                         ` Ingo Molnar
2013-10-01 11:34                           ` [PATCH] perf autodep: Remove strlcpy feature check, add __weak strlcpy implementation Ingo Molnar
2013-10-01 12:04                             ` Ingo Molnar
2013-10-01 12:48                               ` Arnaldo Carvalho de Melo
2013-10-01 12:51                               ` [PATCH] perf autodep: Speed up the 'all features are present' case Ingo Molnar
2013-10-01 14:46                             ` [PATCH] perf tools: Speed up git-version test on re-make Ingo Molnar
2013-10-02  6:47                               ` Namhyung Kim
2013-10-02  6:50                                 ` Ingo Molnar
2013-10-02  8:04                                   ` Namhyung Kim
2013-10-01 15:27                             ` [PATCH] perf autodep: Remove strlcpy feature check, add __weak strlcpy implementation Ingo Molnar
2013-10-01 15:29                               ` [PATCH] perf tools: Speed up the final link Ingo Molnar
2013-10-01  7:04                       ` [PATCH] perf auto-dep: Speed up feature tests by building them in parallel Geert Uytterhoeven
2013-10-01  8:38                         ` Ingo Molnar
2013-10-02  6:05                   ` Namhyung Kim
2013-10-02  6:28                     ` Ingo Molnar
2013-10-02  9:26                   ` Jiri Olsa [this message]
2013-10-02 10:11                     ` Ingo Molnar
2013-09-12 20:18         ` [GIT PULL] perf fixes Ingo Molnar
2013-09-12 20:38           ` Arnaldo Carvalho de Melo
2013-09-12 20:46             ` Ingo Molnar
2013-09-12 21:09               ` David Ahern
2013-09-12 21:18                 ` Ingo Molnar
2013-09-12 22:10                   ` David Ahern
2013-09-13  5:09                     ` Ingo Molnar
2013-09-13  9:32                       ` Jean Pihet
2013-09-13  9:45                         ` Ingo Molnar
2013-09-13 17:15                           ` Jean Pihet
2013-09-12 18:51     ` Linus Torvalds
2013-09-12 20:33       ` Ingo Molnar
2013-09-12 20:38         ` Linus Torvalds
2013-09-12 20:49           ` Ingo Molnar
2013-09-12 20:52             ` Linus Torvalds
2013-09-12 21:01               ` Ingo Molnar
2013-09-12 20:10     ` Ingo Molnar
2013-10-02  7:31   ` [PATCH] tools/perf: Fix double/triple-build of the feature detection logic during 'make install' et al Ingo Molnar
2013-10-02  9:28     ` [PATCH] tools/perf/build: Automatically build in parallel, based on number of CPUs in the system Ingo Molnar

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