Messages in this thread | | | Date | Tue, 20 Oct 2015 23:03:33 +0200 | From | Frederic Weisbecker <> | Subject | Re: [PATCH v8 08/14] nohz_full: allow disabling the 1Hz minimum tick at boot |
| |
On Tue, Oct 20, 2015 at 04:36:06PM -0400, Chris Metcalf wrote: > While the current fallback to 1-second tick is still required for > a number of kernel accounting tasks (e.g. vruntime, load balancing > data, and load accounting), it's useful to be able to disable it > for testing purposes. Paul McKenney observed that if we provide > a mode where the 1Hz fallback timer is removed, this will provide > an environment where new code that relies on that tick will get > punished, and we won't forgive such assumptions silently. > > This option also allows easy testing of nohz_full and task-isolation > modes to determine what functionality needs to be implemented, > and what possibly-spurious timer interrupts are scheduled when > the basic 1Hz tick has been turned off. > > Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
There have been proposals to disable/tune the 1 Hz tick via debugfs which I Nacked because once you give such an opportunity to the users, they will use that hack and never fix the real underlying issue.
For the same reasons, I'm sorry but I have to Nack this proposal as well.
If this is for development or testing purpose, scheduler_max_tick_deferment() is easily commented out.
| |