On Fri, Feb 5, 2016 at 12:13 PM, Andrew Morton <a...@linux-foundation.org> wrote: > On Fri, 5 Feb 2016 10:08:43 -0800 John Stultz <john.stu...@linaro.org> wrote: >> @@ -2218,6 +2222,27 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, >> arg2, unsigned long, arg3, >> case PR_GET_TID_ADDRESS: >> error = prctl_get_tid_address(me, (int __user **)arg2); >> break; >> + case PR_SET_TIMERSLACK_PID: >> + rcu_read_lock(); >> + tsk = find_task_by_vpid((pid_t)arg3); > > hm, as far as I can tell this is the first instance in which prctl() is > used to play with a task other than "current". Maybe this isn't a good > precedent. > > If you look at all the other diddle-other-task functions in > kernel/sys.c, you'll see that they are standalone syscalls. What > you've done here is just a bit lazy: added what is effectively a new > standalone syscall, only it has been hidden within the prctl() switch > statement. > > I don't see a practical problem with this - we could have implemented > all those other syscalls as prctl submodes as well. But we didn't... > > IOW, it would be more consistent to add sys_set_timer_slack()?
I'm fine with moving this way. Ruchi/Rom: Any objections to that idea? Thomas/Arjan: Any other functionality we should consider including when adding a syscall to tweak timer slack? thanks -john
