Paul Eggert <eggert@xxxxxxxxxxx> wrote: > Use gettimeofday instead of time(NULL) to get current time. > This avoids clock skew on glibc 2.31+ on Linux, where in the > first 1 to 2.5 ms of every second, time(NULL) returns a > value that is one less than the tv_sec part of > higher-resolution timestamps such as those returned by > gettimeofday or timespec_get, or those in the file system. > There are similar clock skew problems on AIX and MS-Windows, > which have problems in the first 5 ms of every second. Wow, this is enlightening... and unfortunate :< I decided to check glibc archives to find more discussion on it. So far, I've found: https://inbox.sourceware.org/libc-alpha/20230306160321.2942372-1-adhemerval.zanella@xxxxxxxxxx/T/ and the original bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30200 And this is due to the time64 changes in glibc 2.31+? (<= 2.30 isn't affected?) <snip> > Yet another possibility would be to fix the Linux kernel so > that the time syscall is consistent with the other timestamp > syscalls. I suppose this has not been done due to > performance implications. (Git's use of timestamps is rare > enough that performance is not a significant consideration > for git.) However, this wouldn't fix Git's problem on older > Linux kernels, or on AIX or MS-Windows. Agreed on the older kernels and other OSes part.
