Re: [PATCH] x86: Disable CONFIG_X86_DECODER_SELFTEST in allmod/allyesconfigs

From: Ingo Molnar
Date: Tue Feb 11 2014 - 02:15:47 EST



* Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:

> Hi Ingo,
>
> On Wed, 5 Feb 2014 06:51:37 +0100 Ingo Molnar <mingo@xxxxxxxxxx> wrote:
> >
> >
> > * Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> >
> > > > BTW you probably also want to do the same for the x86 instruction
> > > > decoder test. It seems to be the biggest compile time waster in
> > > > allyesconfig and I usually disable it too.
> > >
> > > Agreed, that should be disabled too by default. Although in that
> > > case I think the COMPILE_TEST combination makes more sense, since
> > > it's a coverage issue.
> >
> > I'd say randconfig will cover it often enough, and the failure is also
> > borderline build coverage related: you cannot really make the decoder
> > test fail via source level changes, only with changes in the build
> > environment, so I agree with Andi that we can disable this one too -
> > via the patch below.
> >
> > Thanks,
> >
> > Ingo
> >
> > Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
> >
> > diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
> > index 0f3621e..f0fca39 100644
> > --- a/arch/x86/Kconfig.debug
> > +++ b/arch/x86/Kconfig.debug
> > @@ -184,6 +184,11 @@ config HAVE_MMIOTRACE_SUPPORT
> > config X86_DECODER_SELFTEST
> > bool "x86 instruction decoder selftest"
> > depends on DEBUG_KERNEL && KPROBES
> > + #
> > + # It can take some time to validate the image,
> > + # make sure {allyes|allmod}config doesn't enable it:
> > + #
> > + depends on !COMPILE_TEST
> > ---help---
> > Perform x86 instruction decoder selftests at build time.
> > This option is useful for checking the sanity of x86 instruction
>
> When this got applied to the tip tree, Linus had already applied an
> earlier version as commit f8f202348208, and this one (commit
> 8c778d541bec) now duplicates the actual dependency in !COMPILE_TEST
> (but does add a useful comment) ...

Ok, I've zapped it from x86/urgent, thanks for letting me know!

Ingo
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