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

From: Brian Gerst
Date: Thu Dec 23 2004 - 15:09:12 EST

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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