On Wed, Oct 16, 2024 at 12:36:00PM +0800, lizhe.67@xxxxxxxxxxxxx wrote: > From: Li Zhe <lizhe.67@xxxxxxxxxxxxx> > > In function collapse_huge_page(), we drop mmap read lock and get > mmap write lock to prevent most accesses to pagetables. There is > a small time window to allow other tasks to acquire the mmap lock. > With the use of upgrade_read(), we don't need to check vma and pmd > again in most cases. This is clearly a performance optimisation. So you must have some numebrs that justify this, please include them.
