On 2015/6/30 11:03, Alex Shi wrote:
On 06/30/2015 01:25 AM, John Stultz wrote:
diff --git a/include/uapi/linux/prctl.h b/include/uapi/linux/prctl.h index 28bb0b3..8c6edff 100644 --- a/include/uapi/linux/prctl.h +++ b/include/uapi/linux/prctl.h @@ -153,7 +153,7 @@
- arg2 slack value, 0 means "use default"
- arg3 pid of the thread whose timer slack needs to be set
*/ -#define PR_SET_TIMERSLACK_PID 41 +#define PR_SET_TIMERSLACK_PID 47
Problem is that the Android userspace is redefining PR_SET_TIMERSLACK_PID back to 41 [1]. So this kernel patch alone would not help.
Yea. I think we need to ping Ruchi at google and try to sync up with their plans. If their userspace is going to switch the PR number based on kernel versions we will also be in trouble. (My usage of 47 was only in the context of submitting it upstream. Once its upstream, that would be the number to migrate to, but not before then).
Yes, merge this into upstream is the right way, but it's also a long way.
Amit & John, Would you like to ping google to do sth on this issue?
YinPing & Peter,
Before everything settling down, seems there is no good way to change sth in LSK. So you may need to modify your kernel according to your using scenarios.
ok,
for compatibility, it is better to upstream this code as soon as possible.
It might be better to have a patch which sets it to 127 or something which obviously won't collide in the near term, and then userspace can probe 127 first to see if its on a newer kernel, then fall back to 41 if its on an older kernel.
That need user APP to do this change. It looks more trouble to require this to common user.
.