Messages in this thread | | | Date | Tue, 21 Dec 2004 14:54:46 -0800 (PST) | From | Christoph Lameter <> | Subject | Re: Increase page fault rate by prezeroing V1 [1/3]: Introduce __GFP_ZERO |
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On Tue, 21 Dec 2004, Andi Kleen wrote:
> Christoph Lameter <clameter@sgi.com> writes: > > @@ -0,0 +1,52 @@ > > +/* > > + * Zero a page. > > + * rdi page > > + */ > > + .globl zero_page > > + .p2align 4 > > +zero_page: > > + xorl %eax,%eax > > + movl $4096/64,%ecx > > + shl %ecx, %esi > > Surely must be shl %esi,%ecx
Ahh. Thanks.
> But for the one instruction it seems overkill to me to have a new > function. How about you just extend clear_page with the order argument?
We can just
#define clear_page(__p) zero_page(__p, 0)
and remove clear_page?
> > BTW I think Andrea has been playing with prezeroing on x86 and > he found no benefit at all. So it's doubtful it makes any sense > on x86/x86-64.
Andrea's approach was:
1. Zero hot pages 2. Zero single pages
which simply results in shifting the processing time somewhere else. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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