Re: [GIT PULL 0/9] perf/core improvements and fixes

[Ingo Molnar <mingo@kernel.org>]

* Ingo Molnar <mingo@kernel.org> wrote:

> 
> * Arnaldo Carvalho de Melo <acme@infradead.org> wrote:
> 
> > Em Fri, Oct 26, 2012 at 04:54:51PM +0200, Ingo Molnar escreveu:
> > > * Arnaldo Carvalho de Melo <acme@infradead.org> wrote:
> > > > . Makefile improvements from Namhyung Kim.
> > > 
> > > These are really useful: there used to be a couple of 
> > > seconds of wait time at the beginning of every perf build - 
> > > these are now nicely explained with the various CHK entries.
> > 
> > The optimal way, I guess, would be to have some cache file 
> > with the results of such feature tests, that would be created 
> > and then used till the build fails using its findings, which 
> > would trigger a new feature check round, followed by an 
> > automatic rebuild.
> > 
> > That would be tricky because we would have to have an 
> > automated way of discovering if the build failed due to 
> > missing packages or if it failed due to some ordinary coding 
> > mistake.
> 
> The feature tests aren't a big problem right now - but making 
> it *visible* is really useful. It also tells us which feature 
> test fails, etc.

Btw., there's another thing that would be nice in addition to 
simplifying the PERF-VERSION-GEN script: to be able to run the 
CHK tests in parallel, like the object file runes.

Right now the CHK tests are serialized and they take several 
seconds to build and run. A parallel make rule would reduce
that to about a second I think.

Thanks,

	Ingo