Messages in this thread | | | From | Arnd Bergmann <> | Date | Wed, 22 Sep 2021 13:27:55 +0200 | Subject | Re: [PATCH v3 2/2] perf bench: Add support for 32-bit systems with 64-bit time_t |
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On Wed, Sep 22, 2021 at 1:06 AM André Almeida <andrealmeid@collabora.com> wrote: > Às 05:08 de 21/09/21, Arnd Bergmann escreveu: > > On Tue, Sep 21, 2021 at 12:47 AM André Almeida > > <andrealmeid@collabora.com> wrote: > >> > >> #if defined(__i386__) || __TIMESIZE == 32 > >> # define NR_gettime64 __NR_clock_gettime64 > >> #else > >> # define NR_gettime64 __NR_clock_gettime > >> #endif > >> > >> struct timespec64 { > >> long long tv_sec; /* seconds */ > >> long long tv_nsec; /* nanoseconds */ > >> }; > >> > >> int gettime64(clock_t clockid, struct timespec64 *tv) > >> { > >> return syscall(NR_gettime64, clockid, tv); > >> } > >> > >> Then we can just use &timeout at __NR_futex_time64 for 32bit arch and at > >> __NR_futex for 64bit arch. > > > > This is still broken when you disable CONFIG_COMPAT_32BIT_TIME, > > which disables all system calls that take time32 arguments. > > > > Oh, I think my point was confusing then. My suggestion was to use only > the futex entry points that accepts time64, and to always use > clock_gettime that uses time64, for all platforms. Then it will work if > we disable CONFIG_COMPAT_32BIT_TIME.
Yes, that would be ok. It does require using at least linux-5.1, but we perf is already sort-of tied to the kernel version.
Arnd
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