Re: [PATCH] Prezeroing V8

[Andrew Morton]

Christoph Lameter <clameter@xxxxxxx> wrote:
>
> On Thu, 17 Mar 2005, Andrew Morton wrote:
> 
>  > > > It's hard to know what to think about this without benchmarking numbers.
> 
>  http://oss.sgi.com/projects/page_fault_performance/

Oh no, not that page again ;)

Seems to say that prezeroing makes negligible difference to kernel builds,
but speeds up a big malloc+memset by 3x to 4x, yes?

Are there any real-worldish workloads which show an appreciable benefit?

The large speedup for a big memset seems odd - I assume it's simply
transferring CPU load from the user's process over to kscrubd.  Or is it
the fancy page-zeroing hardware?  How do we differentiate the two?

Are there any workloads which are seeing a benefit on a CPU which doesn't
have the zeroing hardware?

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