I/O stats for lmtp, imap and pop

[Jeroen van Meeuwen (Kolab Systems)]

On 2012-01-07 6:05, Wesley Craig wrote:
> I don't see a good reason to include code that digs around in /proc
> when getrusage() has the exact same data.  I think adding, e.g., I/O
> to the telemetry calls would be peachy, either as a runtime option or
> if someone wants to exercise their autoconf-foo, at build time as
> appropriate to the platform in question.
>
> When I wrote the getruage() code, I included only system & user CPU
> time because the platform I was working on provided them -- because
> POSIX requires them.  POSIX similarly requires that the other fields
> be present, but they didn't happen to have any content when I wrote
> that code, on the platform I was working on.  The present day version
> of the platform in question (Linux) provides much more data, and most
> non-Linux platforms have provided more than just CPU usage for many
> years.
>

Thanks Oliver and Wes, for the clarification.

I think master, or 2.5+, is definitely something that would run on 
current day systems. I think it's fair enough to state that is Linux 
kernel 2.6+, while 2.6.18 is Red Hat Enterprise Linux 5 / CentOS 5, but 
not 2.4 for example.

If I understand things correctly, it is the Linux kernel that as of 
version 2.6.22 or so is providing all the statistics we'd want?

I guess what remains is to figure out what other (current?) platforms 
support, and if the code can be made so to be compatible across the 
board. I don't think we currently have a complete and exhaustive list of 
supported platforms (and versions), let alone points of contact in the 
community that can verify certain things on certain platforms for us. I 
can work on making this list happen, though.

Can we settle on what we have now, and target we figure things out 
working towards using getrusage() for the statistics wanted?

I agree with Wes that if getrusage() provides the data, and can be made 
to sustainably work on all platforms supported (of which we currently 
have no list), we should target using getrusage(), and avoid probing 
/proc/.

Thanks,

Kind regards,

Jeroen van Meeuwen

-- 
Systems Architect, Kolab Systems AG

e: vanmeeuwen at kolabsys.com
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