On Wed, Oct 18, 2017 at 04:33:43PM +0300, Timofey Titovets wrote: > 2017-10-18 15:34 GMT+03:00 Matthew Wilcox <[email protected]>: > > 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)); > > } > > IIRC kernel have special zero page, and if i understand correctly. > You can map all zero pages to that zero page and not touch zswap completely. > (Your situation look like some KSM case (i.e. KSM can handle pages > with same content), but i'm not sure if that applicable there)
You're confused by the word "same". What Srividya meant was that the page is filled with a pattern, eg 0xfffefffefffefffe..., not that it is the same as any other page.
