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From: "danglin at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libstdc++/98678] 30_threads/future/members/poll.cc execution test FAILs
Date: Tue, 25 Jun 2024 18:15:39 +0000	[thread overview]
Message-ID: <bug-98678-4-eqaQPe4yQF@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-98678-4@http.gcc.gnu.org/bugzilla/>

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

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
  Attachment #58500|0                           |1
        is obsolete|                            |

--- Comment #13 from John David Anglin <danglin at gcc dot gnu.org> ---
Created attachment 58515
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=58515&action=edit
Really fix poll.cc on hppa-linux

hppa-linux doesn't have high resolution timer support.  Timer resolutions
range from 1 to 10ms depending on CONFIG_HZ.  The ready loop takes about
5ns per call.  As a result, we need a lot of iterations to obtain reasonable
accuracy in the ready loop.  I reduced the number of iteration in the
wait_until_sys_epoch and wait_until_steady_epoch loops to 1000 so test
would run in a reasonable time.  The results for these two loops are
currently not checked.

Here is output on 1GHz c8000 with HZ=250:
dave@atlas:~/gnu/gcc/objdir/hppa-linux-gnu/libstdc++-v3/testsuite$ ./poll.exe
wait_for(0s): 4919957362ns for 100000000 calls, avg 49.1996ns per call
wait_until(system_clock minimum): 22053828859ns for 100000000 calls, avg
220.538ns per call
wait_until(steady_clock minimum): 22277782883ns for 100000000 calls, avg
222.778ns per call
wait_until(system_clock epoch): 3999965336ns for 1000 calls, avg 3.99997e+06ns
per call
wait_until(steady_clock epoch: 3999965335ns for 1000 calls, avg 3.99997e+06ns
per call
wait_for when ready: 519995494ns for 100000000 calls, avg 5.19995ns per call

  parent reply	other threads:[~2024-06-25 18:15 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-14 12:16 [Bug libstdc++/98678] New: " ro at gcc dot gnu.org
2021-01-14 12:17 ` [Bug libstdc++/98678] " ro at gcc dot gnu.org
2021-01-14 12:59 ` redi at gcc dot gnu.org
2021-04-19 21:27 ` seurer at gcc dot gnu.org
2021-04-27 11:40 ` jakub at gcc dot gnu.org
2021-07-28  7:05 ` rguenth at gcc dot gnu.org
2022-04-21  7:48 ` rguenth at gcc dot gnu.org
2023-04-05 16:51 ` danglin at gcc dot gnu.org
2023-05-29 10:03 ` jakub at gcc dot gnu.org
2024-06-05 12:12 ` ro at CeBiTec dot Uni-Bielefeld.DE
2024-06-05 12:13 ` ro at gcc dot gnu.org
2024-06-10 17:21 ` danglin at gcc dot gnu.org
2024-06-10 17:31 ` danglin at gcc dot gnu.org
2024-06-23 21:22 ` danglin at gcc dot gnu.org
2024-06-25 18:15 ` danglin at gcc dot gnu.org [this message]
2024-07-04 13:17 ` cvs-commit at gcc dot gnu.org
2024-07-19  6:17 ` rguenth at gcc dot gnu.org

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