Re: [GIT PULL 0/7] perf/core improvements and fixes

[Ingo Molnar <mingo@kernel.org>]

* Jiri Olsa <jolsa@redhat.com> wrote:

> On Tue, Nov 24, 2015 at 09:10:42AM +0100, Ingo Molnar wrote:
> 
> SNIP
> 
> > 
> >   GEN      common-cmds.h
> >   CC       perf-read-vdso32
> >   CC       perf-read-vdsox32
> >   CC       ui/gtk/browser.o
> >   CC       ui/gtk/hists.o
> >   CC       ui/gtk/setup.o
> >   CC       ui/gtk/util.o
> >   CC       ui/gtk/helpline.o
> >   CC       ui/gtk/progress.o
> >   CC       ui/gtk/annotate.o
> >   CC       util/abspath.o
> >   CC       fd/array.o
> > 
> > Auto-detecting system features:
> >   CC       event-parse.o
> > ...                        libelf: [ on  ]
> >   PERF_VERSION = 4.4.rc2.g9327ca
> > ...                           bpf: [ on  ]
> > 
> >   CC       util/alias.o
> >   CC       libbpf.o
> > 
> > 
> > while normally we'd first do feature detection, then only do the build (knowing 
> > which features to build).
> 
> the bpf lib is doing its own feature detection, to be able
> to stand alone.. I'll see if we could share detected features
> somehow, so sub builds don't need to do that
> 
> > 
> > Occasionally it also triggers a build failure:
> > 
> >   CC       plugin_kvm.o
> >   CC       arch/common.o
> >   CC       util/db-export.o
> >   LD       plugin_kmem-in.o
> > fixdep: error opening depfile: ./.plugin_kmem.o.d: No such file or directory
> > /home/mingo/tip/tools/build/Makefile.build:77: recipe for target 'plugin_kmem.o' 
> > failed
> > make[3]: *** [plugin_kmem.o] Error 2
> > Makefile:189: recipe for target 'plugin_kmem-in.o' failed
> > make[2]: *** [plugin_kmem-in.o] Error 2
> > Makefile.perf:424: recipe for target 'install-traceevent-plugins' failed
> > make[1]: *** [install-traceevent-plugins] Error 2
> > make[1]: *** Waiting for unfinished jobs....
> > 
> > that too seems to be a result of unwanted, over-eager parallelism.
> 
> hm, haven't seen that one for long time now ;-) will check

So maybe that's a side effect, because I do:

  make clean install

and maybe 'clean' happens in parallel with 'install'?

Thanks,

	Ingo