Re: O->A loan

[yamt%mwd.biglobe.ne.jp@localhost (YAMAMOTO Takashi)]

hi,

> On Sun, Nov 20, 2011 at 06:52:10PM +0000, YAMAMOTO Takashi wrote:
>> hi,
>> 
>> i'd like to to either fix or remove O->A page loaning.
>> 
>> the biggest problem is the lack of users.  thus no way to test.
>> any ideas?
> 
> some years ago I wrote some prototype code to use the O->A loaning for
> read() and write().  the read() side worked, I don't think I had tested
> the write() side so it probably has problems.  the patch is still around:
> ftp://ftp.netbsd.org/pub/NetBSD/misc/chs/diff.uvm_readloan.8
> 
> it's quite a bit out of date, but I think most of the changes needed
> to update it would be mechanical.

i'll take a look.  thanks.

did it (at least the read() side) have actual performance benefit
compared to dumb copying?

YAMAMOTO Takashi

> 
> -Chuck