Re: counters

[Jerry Cooperstein <coop@axian.com>]

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
> -