Re: [Starpu-devel] Starpu stats about disk, OOC, and swapping

[Amani Alonazi <amani.alonazi@kaust.edu.sa>]

Thanks a lot, Samuel!

Hopefully last question :-) I'm using STARPU_DISK_SWAP_BACKEND=unistd. How can I analyze how much data transferred to disk during OOC computation? Shall I assume that anything exceeds the sustained BW that it runs at  the sustained BW?

I clearly notice the extra time required in executing each tasks with big/smaller STARPU_LIMIT_CPU_MEM. I just want to quantify the amount of transfer in/out to disk.

Many thanks!

A.

On Mon, Jan 14, 2019 at 8:53 PM Samuel Thibault <samuel.thibault@inria.fr> wrote:

Amani Alonazi, le lun. 14 janv. 2019 20:46:45 +0300, a ecrit:
> Indeed. But, StarPU statistics reports more than 90 MB/s, which is the
> sustained BW.

Ah, ok (please always specify what you think looks wrong :) ).

Yes, that may look a bit odd. But that can happen if you are not using
the unistd_o_direct backend, in which case the OS makes some caching.
Even with unistd_o_direct I wouldn't be surprised that the measurements
differ noticeably, since the Linux block scheduler also comes in etc.

Samuel

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