On Fri, 24 Oct 2014 12:47:48 -0700 Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > On Fri, Oct 24, 2014 at 10:32 AM, David Miller <davem@xxxxxxxxxxxxx> 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? -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
