On Thu, Apr 24, 2014 at 09:55:25AM +0100, Chung-Lin Tang wrote: > On 2014/4/24 02:26 PM, Chung-Lin Tang wrote: > > On 2014/4/24 上午 02:15, Pinski, Andrew wrote: > >> > >>>> On Apr 23, 2014, at 10:59 AM, "Chung-Lin Tang" <cltang@xxxxxxxxxxxxxxxx> wrote: > >>>> > >>>>>> On 2014/4/22 07:20 PM, Ley Foon Tan wrote: > >>>>>> On Tue, Apr 22, 2014 at 6:56 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote: > >>>>>>>>>> On Tuesday 22 April 2014 18:37:11 Ley Foon Tan wrote: > >>>>>>>>>>>>>> Hi Arnd and Peter Anvin, > >>>>>>>>>>>>>> > >>>>>>>>>>>>>> Other than 64-bit time_t, clock_t and suseconds_t, can you confirm > >>>>>>>>>>>>>> that we don't need to have 64 bit off_t? See detail in link below. > >>>>>>>>>>>>>> I can submit the patches for 64-bit time changes > >>>>>>>>>>>>>> (include/asm-generic/posix_types.h and other archs) if everyone is > >>>>>>>>>>>>>> agreed on this. > >>>>>>>>>> > >>>>>>>>>> Yes. > >>>>>> Okay, will doing that. > >>>> > >>>> I believe that arm64 ILP32 will also be affected. What is the status of > >>>> this configuration? Has the glibc/kernel ABI been finalized? > >> Not yet. I am still working out the signal handling part. But we > >> already agreed on 64bit time_t, clock_t, and suseconds_t. And we > >> agreed to a 64bit offset_t too. > >> > >> On a related note suseconds in the timespec in posix is defined to > >> be long. So it would nice if the kernel ignores the upper 32bits so > >> we (glibc developers) can fix this for new targets including x32 > >> and arm64/ilp32. > > > > Hmm, but that means for purely 32-bit architectures like nios2, which > > unlike x86_64 or arm64, never has a 64-bit mode, suseconds_t as a 64-bit > > type in the kernel is simply wasted. > > The more I think of this, the more I feel that suseconds_t should jsut > be 'long', not strictly 64-bitified. An ILP32 sub-mode in a 64-bit > kernel should be using compat_* code paths, something like a > COMPAT_USE_32BIT_SUSECONDS case. ILP32 mode should use LP64 syscalls as much as possible and that's the aim with arm64 as well (of course, we still have a few that wouldn't be possible and we route them via compat). But here if time_t is 64-bit while susecconds_t is 32-bit, the compat code wouldn't help. -- Catalin -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
