Re: counters

Jerry Cooperstein
2002-05-17T14:52:22Z

This is doable (some other OS's do it) but:

1) It requires some changes to the basic read/write call to gather
the statistics. It also requires stashing the counters somewhere
such as in the task_struct and thus requires modifying it.

2) It doesn't directly tell you about I/O statistics themselves
(which are available under /proc/stat) because the I/O request
may be gotten from cache, or may never be flushed from cache
to disk depending on subsequent events, so it will always
tend to overestimate the amount of real I/O done on the device.

Jerry Cooperstein <coop@axian.com>
Axian, Inc. Software Consulting and Training
4800 SW Griffith Dr., Ste. 202, Beaverton, OR 97005 USA
http://www.axian.com/

On Thu, May 16, 2002 at 07:44:35PM +0530, Manik Raina wrote:
> anyone knows if there are counters in the linux kernel
> which can be read via /proc like mechanism for the
> following :
>
> 1. total number of bytes read by process by syscalls
> like read()
>
> 2. total number of bytes written by each process by
> syscalls like write()
>
> thanks
> -