[PATCH RFC v1 06/12] staging/gasket: Prepare gasket_release_page() for PG_reserved changes

[David Hildenbrand]

On 22.10.19 19:12, David Hildenbrand wrote:
> Right now, ZONE_DEVICE memory is always set PG_reserved. We want to
> change that.
> 
> The pages are obtained via get_user_pages_fast(). I assume, these
> could be ZONE_DEVICE pages. Let's just exclude them as well explicitly.
> 
> Cc: Rob Springer <rspringer at google.com>
> Cc: Todd Poynor <toddpoynor at google.com>
> Cc: Ben Chan <benchan at chromium.org>
> Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
> Signed-off-by: David Hildenbrand <david at redhat.com>
> ---
>   drivers/staging/gasket/gasket_page_table.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/gasket/gasket_page_table.c b/drivers/staging/gasket/gasket_page_table.c
> index f6d715787da8..d43fed58bf65 100644
> --- a/drivers/staging/gasket/gasket_page_table.c
> +++ b/drivers/staging/gasket/gasket_page_table.c
> @@ -447,7 +447,7 @@ static bool gasket_release_page(struct page *page)
>   	if (!page)
>   		return false;
>   
> -	if (!PageReserved(page))
> +	if (!PageReserved(page) && !is_zone_device_page(page))
>   		SetPageDirty(page);
>   	put_page(page);
>   
> 


@Dan, is SetPageDirty() on ZONE_DEVICE pages bad or do we simply not 
care? I think that ending up with ZONE_DEVICE pages here is very 
unlikely. I'd like to drop this (and the next) patch and document why it 
is okay to do so.

-- 

Thanks,

David / dhildenb