Re: [PATCH v2 00/14] Introducing TIF_NOTIFY_IPI flag
From: Peter Zijlstra
Date: Fri Jun 14 2024 - 21:45:35 EST
On Sat, Jun 15, 2024 at 03:28:14AM +0200, Peter Zijlstra wrote:
> On Fri, Jun 14, 2024 at 12:48:37PM +0200, Vincent Guittot wrote:
> > The main problem is that need_resched becomes somewhat meaningless
> > because it doesn't only mean "I need to resched a task" and we have
> > to add more tests around even for those not using polling
>
> True, however we already had some of that by having the wakeup list,
> that made nr_running less 'reliable'.
Doesn't using !idle_cpu() instead of need_resched() in those balance
paths already do the right thing?
Checking need_resched() as an indicator of it getting work is already a
bit an assumption.
Also, Ingo, idle_cpu() and friends don't really belong in syscalls.c...