Re: extending wait4(2) or waitid(2) linux syscall

[Florian Weimer <fweimer@redhat.com>]

* Arnd Bergmann:

> On Thu, Nov 15, 2018 at 7:38 AM <hpa@zytor.com> wrote:
>> On November 15, 2018 7:30:11 AM PST, "Dmitry V. Levin" <ldv@altlinux.org> wrote:
>> >On Thu, Nov 15, 2018 at 06:39:03AM -0800, Arnd Bergmann wrote:
>> >> On Thu, Nov 15, 2018 at 6:05 AM Dmitry V. Levin wrote:
>> >> > On Thu, Apr 20, 2017 at 03:20:51PM +0200, Albert ARIBAUD wrote:
>
>> >2. The time precision provided by struct rusage returned by wait4(2)
>> >and waitid(2) is too low for syscall time counting (strace -c) nowadays,
>> >this can be observing by running in a row a simple command like "strace -c
>> >pwd".
>> >
>> >The fix is to return a more appropriate structure than struct rusage
>> >by the new pwait6(2)/pwaitid(2) syscall mentioned above, where
>> >struct timeval is replaced with struct timespec or even struct
>> >timespec64.
>>
>> Arnd: w.r.t. our previous discussion, this would seem to justify going to timespec(64) for these kind of cases.
>
> Ok, and I assume we want the same layout for getrusage(2) then, right?

Or introduce something that covers FreeBSD's wait6 functionality as well
(resource usage by subprocesses of the subprocess).

Thanks,
Florian