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

[Srividya Desireddy]

On Wed, Oct 19, 2017 at 6:38 AM, Matthew Wilcox wrote: 
> On Thu, Oct 19, 2017 at 12:31:18AM +0300, Timofey Titovets 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;
>> > +       }
>> > +}
>> 
>> Same here, but with memcpy().
>
>No.  Use memset_l which is optimised for this specific job.

I have tested this patch using memset_l() function in zswap_fill_page() on 
x86 64-bit system with 2GB RAM. The performance remains same. 
But, memset_l() funcion might be optimised in future. 
@Seth Jennings/Dan Streetman:  Should I use memset_l() function in this patch.