Re: [PATCH] Cleanup __pvclock_read_cycles to remove useless variables

From	Andy Lutomirski <luto@amacapital.net>
Newsgroups	linux.kernel
Subject	Re: [PATCH] Cleanup __pvclock_read_cycles to remove useless variables
Date	2016-05-01 00:00 +0200
Message-ID	<rtL5H-6vQ-37@gated-at.bofh.it> (permalink)
References	<rrIEW-1iI-29@gated-at.bofh.it> <rtD85-4Q-1@gated-at.bofh.it> <rtHbI-384-15@gated-at.bofh.it> <rtIAO-4s0-17@gated-at.bofh.it>
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On Apr 30, 2016 12:17 PM, "Borislav Petkov" <bp@suse.de> wrote:
>
> On Sat, Apr 30, 2016 at 10:47:49AM -0700, Andy Lutomirski wrote:
> > Take a look at vread_pvclock.  I decided that __pvclock_read_cycles
> > was too ugly to use and was very slow and I just gave up and rewrote
> > it.
>
> Should we kill __pvclock_read_cycles in favor of vread_pvclock? It looks
> doable at a quick scan...
>

The in-kernel version might have to be a bit different because it
needs to handle the !stable case.  If !stable, it should just use the
current CPU's copy which means that, realistically, it should just
get_cpu and use the local copy unconditionally.  Other than that, it
could look a lot like the vread_pvclock variant.

But I agree, the current thing is incomprehensible.

--Andy

> --
> Regards/Gruss,
>     Boris.
>
> SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg)
> --

Thread

Re: [PATCH] Cleanup __pvclock_read_cycles to remove useless variables Borislav Petkov <bp@suse.de> - 2016-04-30 15:30 +0200
  Re: [PATCH] Cleanup __pvclock_read_cycles to remove useless variables Andy Lutomirski <luto@amacapital.net> - 2016-04-30 19:50 +0200
    Re: [PATCH] Cleanup __pvclock_read_cycles to remove useless variables Borislav Petkov <bp@suse.de> - 2016-04-30 21:20 +0200
      Re: [PATCH] Cleanup __pvclock_read_cycles to remove useless variables Andy Lutomirski <luto@amacapital.net> - 2016-05-01 00:00 +0200
        Re: [PATCH] Cleanup __pvclock_read_cycles to remove useless variables Paolo Bonzini <pbonzini@redhat.com> - 2016-05-11 16:30 +0200
          Re: [PATCH] Cleanup __pvclock_read_cycles to remove useless variables Minfei Huang <mnghuan@gmail.com> - 2016-05-11 17:30 +0200

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