svn commit: r312296 - in head: lib/libc/sys sys/kern sys/netinet sys/netinet6 sys/sys tools/regression/sockets/udp_pingpong tools/regression/sockets/unix_cmsg

[Alan Somers]

On Mon, Jan 16, 2017 at 10:46 AM, Maxim Sobolev <sobomax at freebsd.org> wrote:
> Author: sobomax
> Date: Mon Jan 16 17:46:38 2017
> New Revision: 312296
> URL: https://svnweb.freebsd.org/changeset/base/312296
>
> Log:
>   Add a new socket option SO_TS_CLOCK to pick from several different clock
>   sources to return timestamps when SO_TIMESTAMP is enabled. Two additional
>   clock sources are:
>
>   o nanosecond resolution realtime clock (equivalent of CLOCK_REALTIME);
>   o nanosecond resolution monotonic clock (equivalent of CLOCK_MONOTONIC).
>
>   In addition to this, this option provides unified interface to get bintime
>   (equivalent of using SO_BINTIME), except it also supported with IPv6 where
>   SO_BINTIME has never been supported. The long term plan is to depreciate
>   SO_BINTIME and move everything to using SO_TS_CLOCK.
>
>   Idea for this enhancement has been briefly discussed on the Net session
>   during dev summit in Ottawa last June and the general input was positive.
>
>   This change is believed to benefit network benchmarks/profiling as well
>   as other scenarios where precise time of arrival measurement is necessary.
>
>   There are two regression test cases as part of this commit: one extends unix
>   domain test code (unix_cmsg) to test new SCM_XXX types and another one
>   implementis totally new test case which exchanges UDP packets between two
>   processes using both conventional methods (i.e. calling clock_gettime(2)
>   before recv(2) and after send(2)), as well as using setsockopt()+recv() in
>   receive path. The resulting delays are checked for sanity for all supported
>   clock types.
>
>   Reviewed by:    adrian, gnn
>   Differential Revision:  https://reviews.freebsd.org/D9171

While the new SCM_TIMESTAMP code works fine on both amd64 and i386, it
doesn't work on amd64 under 32-bit emulation.  That is, programs that
use SCM_TIMESTAMP built for i386 will fail when run on an amd64
machine.  I don't know whether this commit introduced that bug; on
stable-10 SCM_TIMESTAMP doesn't appear to work at all on i386.  But
sobomax, since you're obviously familiar with this code, would you
mind taking a look?
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=222039

-Alan