Re: async I/O seems to be blocking on 2.6.15

[Jens Axboe]

On Mon, Nov 06 2006, Chen, Kenneth W wrote:
> I haven't done the measurement whether the time to submit I/O grows
> linearly with respect to I/O size.  Most likely it will.  If it is
> not, then we might have a scaling problem (though I don't believe we
> have this problem).

I would not expect it to, but ran a simple test to check submission
times from 32KiB to 2MiB:

Size		Time (usecs)
----------------------------
2MiB		223
1MiB		112
512KiB		 56
256KiB		 29
128KiB		 14
32KiB		  4

(note that I skipped 64KiB, things got boring). That clearly shows a
linear increase in time, so no scaling problem there.

-- 
Jens Axboe

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