Re: Prezeroing V2 [1/4]: __GFP_ZERO / clear_page() removal

[Brian Gerst]

Christoph Lameter wrote:
> This patch introduces __GFP_ZERO as an additional gfp_mask element to allow
> to request zeroed pages from the page allocator.
>
> o Modifies the page allocator so that it zeroes memory if __GFP_ZERO is set
>
> o Replace all page zeroing after allocating pages by request for
>   zeroed pages.
>
> o requires arch updates to clear_page in order to function properly.
>
> Signed-off-by: Christoph Lameter <clameter@xxxxxxx>

> @@ -125,22 +125,19 @@
>  	int i;
>  	struct packet_data *pkt;
>
> -	pkt = kmalloc(sizeof(struct packet_data), GFP_KERNEL);
> +	pkt = kmalloc(sizeof(struct packet_data), GFP_KERNEL|__GFP_ZERO);
>  	if (!pkt)
>  		goto no_pkt;
> -	memset(pkt, 0, sizeof(struct packet_data));
>
>  	pkt->w_bio = pkt_bio_alloc(PACKET_MAX_SIZE);
>  	if (!pkt->w_bio)

This part is wrong.  kmalloc() uses the slab allocator instead of 
getting a full page.

--
				Brian Gerst
-
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