Re: 5.14-rc breaks iotop swap io monitoring.

[Dave Jones]

On Tue, Aug 24, 2021 at 09:34:02AM -0700, Linus Torvalds wrote:
 > On Tue, Aug 24, 2021 at 8:19 AM Dave Jones <davej@xxxxxxxxxxxxxxxxx> wrote:
 > >
 > > On Tue, Aug 24, 2021 at 10:31:16AM +0200, Peter Zijlstra wrote:
 > >  >
 > >  > If you need DELAYACCT I'm thinking:
 > >  >
 > >  >   e4042ad49235 ("delayacct: Default disabled")
 > >  >
 > >  > and
 > >  >
 > >  >   0cd7c741f01d ("delayacct: Add sysctl to enable at runtime")
 > >
 > > That does sound more relevant. however, even after echo 1  > /proc/sys/kernel/task_delayacct,
 > > it still fails in the same way.
 > 
 > Hmm.
 > 
 > What happens if you boot with the 'delayacct' kernel parameter.
 > 
 > Even if you enable it at run-time, processes that have been started
 > before it was enabled won't actually have the 'tsk->delays'
 > allocation. So I'm not sure how effective the run-time thing is.

Yeah that boot option does make iotop work again.

	Dave