On Tuesday 13 May 2014 22:35:08 Geert Uytterhoeven wrote: > > On Tue, May 13, 2014 at 9:32 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote: > > I think we have three categories: > > Thanks for the list! > > > a) interfaces that uses relative time_t/timespec/timeval: > > b) interfaces that don't make sense for times in the past: > > > c) interfaces that require absolute times: > > - stat/lstat/fstatat/ > > - utime/utimes/futimesat > > > > These absolutely have to use something better than time_t > > both in user space and in the kernel so we can deal with > > old files. A lot of file systems need to be fixed as well so > > we can actually store the times, regardless of whether we > > are running a 32 or 64 bit kernel. > > So these are the ones we have to worry about. > It looks like they all involve I/O? Apart from the case of using block data > from the buffer cache, the 64-bit operations should disappear in the > actual I/O noise, right? Right. Also there have been proposals for a better 'stat' replacement for years, which would solve half of the interface problem for the file system interfaces. However, we also need to find a solution for category b), I only put them into a different category above because we can treat them differently in the kernel. For instance, we could use ktime_t for the kernel code in category b) and a new struct timespec64 for the times in struct inode. On the user interface side, using timespec64 would be a reasonable choice for both categories, because we already have two implementations of all those syscalls in order to handle 32-on-64 compat tasks, and we could use the same set of syscall implementations for time64-on-32. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
