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From: "adhemerval.zanella at linaro dot org" <sourceware-bugzilla@sourceware.org> To: glibc-bugs@sourceware.org Subject: [Bug time/30200] time sometimes appears to go backwards Date: Tue, 21 Mar 2023 16:02:36 +0000 [thread overview] Message-ID: <bug-30200-131-ncWRsRZAFs@http.sourceware.org/bugzilla/> (raw) In-Reply-To: <bug-30200-131@http.sourceware.org/bugzilla/> https://sourceware.org/bugzilla/show_bug.cgi?id=30200 --- Comment #14 from Adhemerval Zanella <adhemerval.zanella at linaro dot org> --- (In reply to Bruno Haible from comment #13) > (In reply to Adhemerval Zanella from comment #12) > > So this problem *always* existed > > From "This problem always existed" you cannot imply "This problem never > caused trouble, otherwise it would have been reported". I will quote myself "I completely agree with you [Paul] that this is problematic" to make it clear I agree this is a problem. I even sent a fix to make it use the same clock for all time interface that does not specify the clock id [1], although I ended up retiring it because Florian explicit say he would revert it on RH distros because of performance implications. [1] https://sourceware.org/pipermail/libc-alpha/2023-March/146088.html > > In https://sourceware.org/pipermail/libc-alpha/2023-March/146219.html I > explain: > > On a typical system, there are > - hundreds of programs that call gettimeofday() or timespec_get(), > - hundreds of programs that call time(). > Each time a program calls gettimeofday() or timespec_get(), and then, > within 1 to 3 milliseconds, a program (the same or a different one) > calls time(), there is the potential for trouble because the time > appears to go backwards. This trouble can occur with probability > between 0.1% and 0.3%. > > This is the kind of trouble that does occur, but that people don't report > because > - it occurs only 1 in 300 to 1000 times, > - it is nearly impossible to track down to glibc, since it will appear as an > interoperation bug between two different programs in the first place. -- You are receiving this mail because: You are on the CC list for the bug.
next prev parent reply other threads:[~2023-03-21 16:02 UTC|newest] Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-03-05 17:21 [Bug time/30200] New: " bruno at clisp dot org 2023-03-05 17:22 ` [Bug time/30200] " bruno at clisp dot org 2023-03-05 17:23 ` bruno at clisp dot org 2023-03-05 17:55 ` girish946 at gmail dot com 2023-03-05 18:28 ` schwab@linux-m68k.org 2023-03-05 18:58 ` schwab@linux-m68k.org 2023-03-05 19:04 ` bruno at clisp dot org 2023-03-06 12:15 ` adhemerval.zanella at linaro dot org 2023-03-06 12:25 ` fweimer at redhat dot com 2023-03-06 12:45 ` bruno at clisp dot org 2023-03-06 13:08 ` adhemerval.zanella at linaro dot org 2023-03-06 13:14 ` fweimer at redhat dot com 2023-03-19 23:43 ` eggert at cs dot ucla.edu 2023-03-21 4:18 ` sam at gentoo dot org 2023-03-21 15:06 ` adhemerval.zanella at linaro dot org 2023-03-21 15:29 ` bruno at clisp dot org 2023-03-21 16:02 ` adhemerval.zanella at linaro dot org [this message] 2023-03-21 20:00 ` bruno at clisp dot org 2023-03-21 20:03 ` adhemerval.zanella at linaro dot org 2023-03-21 20:25 ` fw at deneb dot enyo.de 2023-03-21 20:41 ` adhemerval.zanella at linaro dot org
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