Re: [PATCH] x86/sgx: Fix free page accounting

[Jarkko Sakkinen]

On Sun, 2021-11-07 at 18:45 +0200, Jarkko Sakkinen wrote:
> On Thu, 2021-11-04 at 11:28 -0700, Reinette Chatre wrote:
> > The consequence of sgx_nr_free_pages not being protected is that
> > its value may not accurately reflect the actual number of free
> > pages on the system, impacting the availability of free pages in
> > support of many flows. The problematic scenario is when the
> > reclaimer never runs because it believes there to be sufficient
> > free pages while any attempt to allocate a page fails because there
> > are no free pages available. The worst scenario observed was a
> > user space hang because of repeated page faults caused by
> > no free pages ever made available.
> 
> Can you go in detail with the "concrete scenario" in the commit
> message? It does not have to describe all the possible scenarios
> but at least one sequence of events.

I.e. I don't have anything fundamentally against changing it to
atomic but the commit message is completely lacking the stimulus
of changing anything.

/Jarkko