Re: counters

Frank Schaefer
2002-05-20T05:22:23Z

that's right, but it would give one a picture how much a process --let's
say-- requests I/O.

Regards
Frank

On Fri, 2002-05-17 at 16:52, Jerry Cooperstein wrote:
> 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
> > -
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