On Tue, Apr 27, 2021 at 9:59 AM Michael Pratt <mpr...@google.com> wrote: > > Oops, I should say the syscall package could do this. x/sys/unix has the > extra complexity of not being tied to a Go release.
It's a good idea, although I'll note that the syscall package does not currently define ClockGettime. I think it would be manageable to use build tags to do this in x/sys/unix. Ian > On Tue, Apr 27, 2021, 12:53 Michael Pratt <mpr...@google.com> wrote: >> >> I'm not sure if calling through the VDSO is the best solution to this >> specific issue, though it does sound like a case that would certainly >> benefit. >> >> Regardless, one fairly clean way we could support this would be to make >> x/sys/unix.ClockGettime (and Gettimeofday) call through the VDSO rather than >> performing the syscall. That is always a valid operation (the VDSO will make >> the syscall if it doesn't support the specific options passed), and I think >> would solve this problem without even changing the API. It seems we don't do >> that already for simplicity of implementation and prior lack of need. >> >> On Tue, Apr 27, 2021 at 12:13 PM Ian Lance Taylor <i...@golang.org> wrote: >>> >>> On Tue, Apr 27, 2021, 8:55 AM Manlio Perillo <manlio.peri...@gmail.com> >>> wrote: >>>> >>>> Il giorno martedì 27 aprile 2021 alle 17:51:46 UTC+2 Ian Lance Taylor ha >>>> scritto: >>>>> >>>>> On Tue, Apr 27, 2021 at 7:43 AM Manlio Perillo <manlio....@gmail.com> >>>>> wrote: >>>>> > >>>>> > Il giorno lunedì 26 aprile 2021 alle 10:24:09 UTC+2 Pure White ha >>>>> > scritto: >>>>> >> >>>>> >> So I really want to know what is the right way to do vdso call outside >>>>> >> runtime? >>>>> >> >>>>> > What about using a different function instead of time.Now, and using >>>>> > RawSyscall? >>>>> >>>>> That wouldn't be a VDSO call. VDSO calls are in general faster than >>>>> system calls. There is more background at >>>>> https://man7.org/linux/man-pages/man7/vdso.7.html. >>>>> >>>>> Ian >>>> >>>> >>>> Yes, that wouldn't a VDSO call. But since a VDSO call will require cgo , >>>> maybe RawSyscall will be more efficient? >>> >>> >>> The meaningful comparison is to time.Now, which uses VDSO. I suppose it is >>> possible that RawSyscall of clock_gettime with a coarse clock would be >>> faster than time.Now, but I would be surprised. >>> >>> Ian >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "golang-nuts" group. >>> To unsubscribe from this group and stop receiving emails from it, send an >>> email to golang-nuts+unsubscr...@googlegroups.com. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/golang-nuts/CAOyqgcX9mfSFq5gucrTCi0PJyVdLzA2xGXNByDeOGOyaFLo1hA%40mail.gmail.com. -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/CAOyqgcX69R0dEmPjhBvJ0Z5twMqysuP6WMV6dq5WzsPeLSto3A%40mail.gmail.com.
