Messages in this thread | | | Date | Tue, 28 Oct 2014 10:49:18 +0000 | From | Steve Capper <> | Subject | Re: [GIT] Sparc |
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On Mon, Oct 27, 2014 at 06:43:27PM -0400, David Miller wrote: > From: Andrew Morton <akpm@linux-foundation.org> > Date: Mon, 27 Oct 2014 14:09:38 -0700 > > > Perhaps sparc should be defining CONFIG_HAVE_GENERIC_RCU_GUP. > > > > We really should switch x86 to the generic version - from a quick read > > it looks like it will work without needing any changes. > > > > Steve, thoughts? > > We need to add the necessary hooks to the generic code so that x86 > doesn't so specualtive gets and instead do direct increments, > otherwise it's a performance regression, and then sparc can make use > of that as well.
Agreed, I think x86 may require a helper to read 64-bit ptes (as it can't do that atomically). Also I think there's some subtlety in the way access_ok works that should be checked.
The overall structure of the code looks the same to me, and I think it would be beneficial to extend then use the generic version for x86.
Cheers, -- Steve
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