Messages in this thread | | | Date | Mon, 27 Oct 2014 14:09:38 -0700 | From | Andrew Morton <> | Subject | Re: [GIT] Sparc |
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On Fri, 24 Oct 2014 12:47:48 -0700 Linus Torvalds <torvalds@linux-foundation.org> wrote:
> On Fri, Oct 24, 2014 at 10:32 AM, David Miller <davem@davemloft.net> wrote: > > > > It's really idiotic to have a weak symbolled fallback that just > > returns zero, and causes this kind of bug. There should be no > > backup implementation and the link should fail if the architecture > > fails to provide __get_user_pages_fast() and supports transparent > > hugepages. > > Agreed. I think the weak fallback is for the "no hugepages support" > case, but that does sound very annoying and fragile. >
Yup. I'm thinking the get_user_pages_fast() and __get_user_pages_fast() in mm/util.c should be made non-weak and moved to mm/nommu.c.
With that change, MMU architctures will need to either define CONFIG_HAVE_GENERIC_RCU_GUP or implement their own versions.
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?
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