Re: [PATCH] xfs: stop using the page cache to back the buffer cache

[Christoph Hellwig <hch@xxxxxxxxxxxxx>]

> +             if (((unsigned long)(bp->b_addr + bp->b_buffer_length - 1) &
> +                                                             PAGE_MASK) !=
> +                 ((unsigned long)bp->b_addr & PAGE_MASK)) {
> +                     /* b_addr spans two pages - use alloc_page instead */
> +                     kmem_free(bp->b_addr);
> +                     bp->b_addr = NULL;
> +                     goto use_alloc_page;
> +             }

Did you manage to hit this case?  If it happens with any frequency under
real workloads we really need to find a wayto avoid the allocation to
start with.


Otherwise looks good,

Reviewed-by: Christoph Hellwig <hch@xxxxxx>