Re: [PATCH] hugetlbfs: Take read_lock on i_mmap for PMD sharing

[Andrew Morton]

On Thu, 7 Nov 2019 18:04:56 -0800 Davidlohr Bueso <dave@xxxxxxxxxxxx> wrote:

> On Thu, 07 Nov 2019, Mike Kravetz wrote:
> 
> >Note that huge_pmd_share now increments the page count with the semaphore
> >held just in read mode.  It is OK to do increments in parallel without
> >synchronization.  However, we don't want anyone else changing the count
> >while that check in huge_pmd_unshare is happening.  Hence, the need for
> >taking the semaphore in write mode.
> 
> This would be a nice addition to the changelog methinks.

Done.