[PATCH v5 01/11] asm-generic/pgtable: Adds generic functions to monitor lockless pgtable walks

[Kirill A. Shutemov]

On Sat, Oct 05, 2019 at 02:05:29PM +0530, Aneesh Kumar K.V wrote:
> MADV_DONTNEED has caused us multiple issues due to the fact that it can run
> in parallel to page fault. I am not sure whether we have a known/noticeable
> performance gain in allowing that with mmap_sem held in read mode.

Yes we do. MADV_DONTNEED used a lot by userspace memory allocators and it
will be very noticible performance regression if we would switch it to
down_write(mmap_sem).

-- 
 Kirill A. Shutemov