Re: [PATCH] async_tx: use memchr_inv

From: Vinod Koul
Date: Mon Oct 29 2012 - 01:07:24 EST


On Sun, 2012-10-28 at 00:49 +0900, Akinobu Mita wrote:
> Use memchr_inv() to check the specified page is filled with zero.
>
> Signed-off-by: Akinobu Mita <akinobu.mita@xxxxxxxxx>
> Cc: Vinod Koul <vinod.koul@xxxxxxxxx>
> Cc: Dan Williams <djbw@xxxxxx>
> ---
Looks fine to me, need Dan;s ack before applying

> crypto/async_tx/async_xor.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/crypto/async_tx/async_xor.c b/crypto/async_tx/async_xor.c
> index 154cc84..8ade0a0 100644
> --- a/crypto/async_tx/async_xor.c
> +++ b/crypto/async_tx/async_xor.c
> @@ -230,9 +230,7 @@ EXPORT_SYMBOL_GPL(async_xor);
>
> static int page_is_zero(struct page *p, unsigned int offset, size_t len)
> {
> - char *a = page_address(p) + offset;
> - return ((*(u32 *) a) == 0 &&
> - memcmp(a, a + 4, len - 4) == 0);
> + return !memchr_inv(page_address(p) + offset, 0, len);
> }
>
> static inline struct dma_chan *


--
Vinod Koul
Intel Corp.

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