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. Thanks, Davidlohr
