[Bug libstdc++/98678] New: 30_threads/future/members/poll.cc execution test FAILs

[Bug libstdc++/98678] New: 30_threads/future/members/poll.cc execution test FAILs

[ro at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98678

            Bug ID: 98678
           Summary: 30_threads/future/members/poll.cc execution test FAILs
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ro at gcc dot gnu.org
  Target Milestone: ---
            Target: i386-pc-solaris2.11, x86_64-pc-solaris2.11,
                    arm-none-linux-gnueabi, hppa-unknown-linux-gnu,
                    x86_64-pc-linux-gnu

The 30_threads/future/members/poll.cc reliably FAILs on 32 and 64-bit
Solaris/x86:

/vol/gcc/src/hg/master/local/libstdc++-v3/testsuite/30_threads/future/members/poll.cc:95:
int main(): Assertion 'wait_until_sys_min < (ready * 100)' failed.
wait_for(0s): 11892ns for 200 calls, avg 59.46ns per call
wait_until(system_clock minimum): 1304458ns for 200 calls, avg 6522.29ns per
call
wait_until(steady_clock minimum): 1403221ns for 200 calls, avg 7016.1ns per
call
wait_until(system_clock epoch): 3343806ns for 200 calls, avg 16719ns per call
wait_until(steady_clock epoch: 2959581ns for 200 calls, avg 14797.9ns per call
wait_for when ready: 10969ns for 200 calls, avg 54.845ns per call

While I don't see the failure on Solaris/SPARC, there are reports for a couple
of other targets on gcc-testresults.  However, the Linux/x86_64 ones seem to
only affect the gcc-10 branch.

[Bug libstdc++/98678] 30_threads/future/members/poll.cc execution test FAILs

[ro at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98678

Rainer Orth <ro at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |11.0

[Bug libstdc++/98678] 30_threads/future/members/poll.cc execution test FAILs

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98678

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2021-01-14
             Status|UNCONFIRMED                 |NEW

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
The relevant part of the std::future code on the gcc-10 branch is very
different, so the timings are different on the branch too.

This test is a bit tricky. The whole point is to check that performance of one
operation is acceptable compared to a baseline. But the definition of
"acceptable" and the relative difference between the speed of the different
operations varies with arch. We could just increase the tolerances, but then we
allow worse performance on the targets that don't need it. Maybe we want to
change the 30 and 100 magic numbers to depend on the target.

[Bug libstdc++/98678] 30_threads/future/members/poll.cc execution test FAILs

[seurer at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98678

seurer at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |seurer at gcc dot gnu.org
             Target|i386-pc-solaris2.11,        |i386-pc-solaris2.11,
                   |x86_64-pc-solaris2.11,      |x86_64-pc-solaris2.11,
                   |arm-none-linux-gnueabi,     |arm-none-linux-gnueabi,
                   |hppa-unknown-linux-gnu,     |hppa-unknown-linux-gnu,
                   |x86_64-pc-linux-gnu         |x86_64-pc-linux-gnu,
                   |                            |powerpc64-linux-gnu

--- Comment #2 from seurer at gcc dot gnu.org ---
FYI I am seeing this every so often on powerpc64 BE on an older power 7
machine, too.

[Bug libstdc++/98678] 30_threads/future/members/poll.cc execution test FAILs

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98678

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|11.0                        |11.2

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 11.1 has been released, retargeting bugs to GCC 11.2.

[Bug libstdc++/98678] 30_threads/future/members/poll.cc execution test FAILs

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98678

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|11.2                        |11.3

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 11.2 is being released, retargeting bugs to GCC 11.3

[Bug libstdc++/98678] 30_threads/future/members/poll.cc execution test FAILs

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98678

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|11.3                        |11.4

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 11.3 is being released, retargeting bugs to GCC 11.4.

[Bug libstdc++/98678] 30_threads/future/members/poll.cc execution test FAILs

[danglin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98678

John David Anglin <danglin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |danglin at gcc dot gnu.org

--- Comment #6 from John David Anglin <danglin at gcc dot gnu.org> ---
Fails consistently with timeout on hppa-unknown-linux-gnu. Increasing timeout
doesn't help.

dave@mx3210:~/gnu/gcc/objdir/hppa-linux-gnu/libstdc++-v3/testsuite$ time
./poll.exe
wait_for(0s): 10000098ns for 169420 calls, avg 59.0255ns per call
wait_until(system_clock minimum): 40000394ns for 169420 calls, avg 236.102ns
per call
wait_until(steady_clock minimum): 50000492ns for 169420 calls, avg 295.127ns
per call
wait_until(system_clock epoch): 1695216533549ns for 169420 calls, avg
1.0006e+07ns per call
wait_until(steady_clock epoch: 1694205876189ns for 169420 calls, avg 1e+07ns
per call
wait_for when ready: 0ns for 169420 calls, avg 0ns per call
/home/dave/gnu/gcc/gcc/libstdc++-v3/testsuite/30_threads/future/members/poll.cc:129:
int main(): Assertion 'wait_for_0 < (ready * 30)' failed.
Aborted (core dumped)

real    56m29.632s
user    0m5.355s
sys     0m8.722s

[Bug libstdc++/98678] 30_threads/future/members/poll.cc execution test FAILs

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98678

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|11.4                        |11.5

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 11.4 is being released, retargeting bugs to GCC 11.5.