Re: [RFC PATCH] time/nohz: allow the boot CPU to be nohz_full

2019-01-23 Thread Frederic Weisbecker
On Wed, Jan 23, 2019 at 06:25:26PM +1000, Nicholas Piggin wrote: > Frederic Weisbecker's on January 17, 2019 3:54 am: > > On Mon, Jan 14, 2019 at 04:47:45PM +1000, Nicholas Piggin wrote: > >> We have a supercomputer site testing nohz_full to reduce jitter with > >> good results, but they want CPU0

Re: [RFC PATCH] time/nohz: allow the boot CPU to be nohz_full

2019-01-23 Thread Nicholas Piggin
Frederic Weisbecker's on January 17, 2019 3:54 am: > On Mon, Jan 14, 2019 at 04:47:45PM +1000, Nicholas Piggin wrote: >> We have a supercomputer site testing nohz_full to reduce jitter with >> good results, but they want CPU0 to be nohz_full. That happens to be >> the boot CPU, which is disallowed

Re: [RFC PATCH] time/nohz: allow the boot CPU to be nohz_full

2019-01-16 Thread Frederic Weisbecker
On Mon, Jan 14, 2019 at 04:47:45PM +1000, Nicholas Piggin wrote: > We have a supercomputer site testing nohz_full to reduce jitter with > good results, but they want CPU0 to be nohz_full. That happens to be > the boot CPU, which is disallowed by the nohz_full code. > > They have existing job

[RFC PATCH] time/nohz: allow the boot CPU to be nohz_full

2019-01-13 Thread Nicholas Piggin
We have a supercomputer site testing nohz_full to reduce jitter with good results, but they want CPU0 to be nohz_full. That happens to be the boot CPU, which is disallowed by the nohz_full code. They have existing job scheduling code which wants this, I don't know too much detail beyond that, but