On Tue, Nov 23, 2021 at 9:20 AM David Hildenbrand [off-list ref] wrote:

On 23.11.21 18:17, Shakeel Butt wrote:

quoted

On Tue, Nov 23, 2021 at 8:57 AM David Hildenbrand [off-list ref] wrote:

quoted

[...]

quoted

quoted

quoted

I do wonder which these locking contexts are exactly, and if we could
also do the same thing on ordinary munmap -- because I assume it can be
similarly problematic for some applications.

This is a good question regarding munmap. One main difference is
munmap takes mmap_lock in write mode and usually performance critical
applications avoid such operations.

Maybe we can extend it too most page zapping, if that makes things simpler.

Do you mean doing sync THP split for most of page zapping functions
(but only if that makes things simpler)?

Yes -- if there are no downsides.

I will try. At the moment the assumption of "Not null zap_details
implies leave swap entries" is giving me a headache.

Thanks for the suggestions and your time.