Some positive feedback on the responsiveness of bzr(explorer)

[Martitza Mendez]

On Mon, May 9, 2011 at 10:20 PM, John Arbash Meinel
<john at arbash-meinel.com>wrote:

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> ...
> >> Maximum memory consumption during commit was 315MB.  Total page faults
> >> about 800,000 (on a machine with 2GB RAM).
> >
> > What is "Total page faults"?
>
> A page fault is when a program wants to access a bit of virtual memory
> but it isn't actually present in memory.
> http://en.wikipedia.org/wiki/Page_fault
>
> This happens in a variety of contexts. One is during "swapping", when
> the OS runs out of memory and writes the virtual pages to disk. Then
> when the program accesses them again, it has to read back from disk.
>
> I *think* it might also happen based on how you allocate. I know in
> Linux you can do tons of mallocs(), but until you touch the memory it
> doesn't actually assign real memory to your process. I believe you don't
> hit a page fault during malloc() just during the later access.
>
>
This set of observations was on WinXP (I should have mentioned that).  And
I'm actually not sure whether or how 'lazy' memory allocation is on WIn32.
Good question.  I suppose I should know.  I'll have to test that when I get
a few minutes.

~M
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