On Sat, Mar 16, 2013 at 2:24 PM, Dan Magenheimer <dan.magenheimer@xxxxxxxxxx> wrote: >> From: Konrad Rzeszutek Wilk [mailto:konrad@xxxxxxxxxx] >> Subject: Re: [PATCH v2 1/4] introduce zero filled pages handler >> >> > + >> > + for (pos = 0; pos < PAGE_SIZE / sizeof(*page); pos++) { >> > + if (page[pos]) >> > + return false; >> >> Perhaps allocate a static page filled with zeros and just do memcmp? > > That seems like a bad idea. Why compare two different > memory locations when comparing one memory location > to a register will do? > Good point. I was hoping there was an fast memcmp that would do fancy SSE registers. But it is memory against memory instead of registers. Perhaps a cunning trick would be to check (as a shortcircuit) check against 'empty_zero_page' and if that check fails, then try to do the check for each byte in the code? > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>