On Fri, Nov 20, 2020 at 2:23 PM Arnd Bergmann <arnd@xxxxxxxxxx> wrote: > > On Fri, Nov 20, 2020 at 5:01 PM Willem de Bruijn > <willemdebruijn.kernel@xxxxxxxxx> wrote: > > > > On Fri, Nov 20, 2020 at 3:13 AM Arnd Bergmann <arnd@xxxxxxxxxx> wrote: > > > > > > On Thu, Nov 19, 2020 at 9:13 PM Willem de Bruijn > > > <willemdebruijn.kernel@xxxxxxxxx> wrote: > > > > On Thu, Nov 19, 2020 at 10:45 AM Arnd Bergmann <arnd@xxxxxxxxxx> wrote: > > > Thanks for the suggestion. > > > > I do have an initial patchset. As expected, it does involve quite a > > bit of code churn to pass slack through the callers. I'll take a look > > at your suggestion to simplify it. > > > > As is, the patchset is not ready to send to the list for possible > > merge. In the meantime, I did push the patchset to github at > > https://github.com/wdebruij/linux/commits/epoll-nstimeo-1 . I can send > > a version marked RFC to the list if that's easier. > > Looks all good to me, just two small things I noticed that you can > address before sending the new series: > > * The div_u64_rem() in ep_timeout_to_timespec() looks wrong, as > you are actually dividing a 'long' that does not need it. > > * In "epoll: wire up syscall epoll_pwait2", the alpha syscall has the > wrong number, it > should be 110 higher than the others, not 109. Thanks! I'll fix these up. > > Btw, the other change, to convert epoll implementation to timespec64 > > before adding the syscall, equally adds some code churn compared to > > patch v3. But perhaps the end state is cleaner and more consistent. > > Right, that's what I meant. If it causes too much churn, don't worry > about it it. I think it'll be better to split the patchsets: epoll: convert internal api to timespec64 epoll: add syscall epoll_pwait2 epoll: wire up syscall epoll_pwait2 selftests/filesystems: expand epoll with epoll_pwait2 and select: compute slack based on relative time epoll: compute slack based on relative time and judge the slack conversion on its own merit. I also would rather not tie this up with the compat deduplication. Happy to take a stab at that though. On that note, when combining functions like int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp, fd_set __user *exp, struct timespec64 *end_time, u64 slack) and static int compat_core_sys_select(int n, compat_ulong_t __user *inp, compat_ulong_t __user *outp, compat_ulong_t __user *exp, struct timespec64 *end_time, u64 slack) by branching on in_compat_syscall() inside get_fd_set/set_fd_set and deprecating their compat_.. counterparts, what would the argument pointers look like? Or is that not the approach you have in mind?
