Re: [PATCH] zswap: Same-filled pages handling

[Matthew Wilcox]

On Wed, Oct 18, 2017 at 10:48:32AM +0000, Srividya Desireddy wrote:
> +static void zswap_fill_page(void *ptr, unsigned long value)
> +{
> +	unsigned int pos;
> +	unsigned long *page;
> +
> +	page = (unsigned long *)ptr;
> +	if (value == 0)
> +		memset(page, 0, PAGE_SIZE);
> +	else {
> +		for (pos = 0; pos < PAGE_SIZE / sizeof(*page); pos++)
> +			page[pos] = value;
> +	}
> +}

I think you meant:

static void zswap_fill_page(void *ptr, unsigned long value)
{
	memset_l(ptr, value, PAGE_SIZE / sizeof(unsigned long));
}

(and you should see significantly better numbers at least on x86;
I don't know if anyone's done an arm64 version of memset_l yet).