Re: [RFC v10 PATCH 1/3] mm: mmap: zap pages with read mmap_sem in munmap

[Matthew Wilcox]

On Sat, Sep 15, 2018 at 04:34:57AM +0800, Yang Shi wrote:
> Suggested-by: Michal Hocko <mhocko@xxxxxxxxxx>
> Suggested-by: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx>
> Suggested-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>

Reviewed-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>

Looks good!  Thanks for sticking with this patch series.

Minor spelling fixes:

> -	/*
> -	 * Remove the vma's, and unmap the actual pages
> -	 */
> +	/* Detatch vmas from rbtree */

"Detach"

> +	/*
> +	 * mpx unmap need to be handled with write mmap_sem. It is safe to
> +	 * deal with it before unmap_region().
> +	 */

	 * mpx unmap needs to be called with mmap_sem held for write.
	 * It is safe to call it before unmap_region()

> +	ret = __do_munmap(mm, start, len, &uf, downgrade);
> +	/*
> +	 * Returning 1 indicates mmap_sem is down graded.
> +	 * But 1 is not legal return value of vm_munmap() and munmap(), reset
> +	 * it to 0 before return.
> +	 */

"downgraded" is one word.