Re: [v3 4/5] KVM: PPC: Book3S HV: retry page migration before erroring-out H_SVM_PAGE_IN

On Mon, Jul 13, 2020 at 03:20:43PM +0530, Bharata B Rao wrote:

On Sat, Jul 11, 2020 at 02:13:46AM -0700, Ram Pai wrote:

quoted

The page requested for page-in; sometimes, can have transient
references, and hence cannot migrate immediately. Retry a few times
before returning error.

As I noted in the previous patch, we need to understand what are these
transient errors and they occur on what type of pages?

Its not clear when they occur. But they occur quite irregularly and they 
do occur on pages that were shared in the previous boot.

The previous patch also introduced a bit of retry logic in the
page-in path. Can you consolidate the retry logic into a separate
patch?

yes. having the retry logic in a seperate patch gives us the flexibility
to drop it, if needed.  The retry patch is not the core element of this
patch series.

RP