Re: Nigel's current for-rafael queue

[Rafael J. Wysocki]

On Saturday, September 25, 2010, Nigel Cunningham wrote:
> Hi Rafael.

Hi Nigel,

> Please find attached a slightly updated version of the patchset I sent
> a few months ago. The main change is that I've prepended and additional
> patch which lets the user see the speed at which the image is being
> read and written. This is accomplished by recording the MB/s in a single
> byte in the image header, and using a couple of __nosavedata variables
> to get the data back through the atomic restore. I realise the char limits
> us to 255MB/s at the moment. In future patches, I intend to address this
> by storing the data in a 'proper' image header (it's a real problem -
> TuxOnIce reads and writes on the same set up at speeds around 250MB/s).
> 
> Results on my Dell XPS M1530, which has an SSD hard drive are:
> 
> With just patch 1 applied:
> Attempt 1: Write 74MB/s; Read 52MB/s
> Attempt 2: Write 68MB/s; Read 52MB/s
> Attempt 3: Write 73MB/s; Read 53MB/s
> 
> With the whole sequence:
> Attempt 1: Write 181MB/s; Read 52MB/s
> Attempt 2: Write 156MB/s; Read 53MB/s
> Attempt 3: Write 160MB/s; Read 52MB/s

Thanks for the patches, they look like a real improvement to me.

I only had a couple of minor comments, sent separately in replies to individual
patches.  I'd like to push this series for 2.6.37, if the comments are
addressed timely.

Best regards,
Rafael
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