pcp
[Top] [All Lists]

Re: [pcp] add thread count to linux_proc

To: pcp@xxxxxxxxxxx
Subject: Re: [pcp] add thread count to linux_proc
From: Ken McDonell <kenj@xxxxxxxxxxxxxxxx>
Date: Wed, 15 May 2013 07:34:56 +1000
Delivered-to: pcp@xxxxxxxxxxx
In-reply-to: <5192AB4E.7090202@xxxxxxxxxx>
References: <5192AB4E.7090202@xxxxxxxxxx>
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130329 Thunderbird/17.0.5
One small nit Stan ...

I think proc.psinfo.threads should have the semantics of PM_SEM_INSTANT rather than PM_SEM_DISCRETE ... the number of threads can go up and down during the life of the process, which is a better semantic match to PM_SEM_INSTANT.

PM_SEM_DISCRETE is intended for metrics that once observed are very unlikely to change over time, e.g. the number of CPUs in a system or the kernel's hz value.

The only case where it makes a difference is when the metric appears in an archive, for PM_SEM_DISCRETE there are no interpolated values beyond the last observed value (playing forwards) nor before the first observed value (when playing backwards). But for PM_SEM_DISCRETE provided the value appears once in the archive, then a value is available from the start of the archive to the end of the archive.

On 15/05/13 07:23, Stan Cox wrote:
This adds VmSwap and Threads to linux_proc as proc.memory.vmswap and
proc.psinfo.threads.
...

<Prev in Thread] Current Thread [Next in Thread>