Re: Tracking vm activity

[William Cohen <wcohen at redhat dot com>]

Stone, Joshua I wrote:
> William Cohen wrote:
> > I am playing around with getting information about page faults and I 
> > noticed that there is a probe alias for the entry for the pagefault 
> > code. However, there is no matching probe point for the return. It is 
> > useful to look at the return value to determine what kind of page 
> > fault occurred (major or minor). The attached patch provides a similar 
> > probe point for the return point. any comments on the patch?
>
> I see that you committed it, and added a variable for the return value 
> (fault_type).  Could you elaborate in the documentation what the 
> possible types are (major, minor) and their values?
>
> Thanks,
>
> Josh

Hi Josh,

Is this suitable for comment for vm.pagefault.return? If suitable, I will go 
ahead and check it in.


/* probe vm.pagefault.return
 *
 *  Records type of fault that occurred.
 *
 * Context:
 *  The process which triggered the fault.
 *
 * Argumentss:
 *  fault_type - type of fault
 *	VM_FAULT_OOM	0	out of memory
 *	VM_FAULT_SIGBUS	1	if not oom, minor, or major fault, this val
 *	VM_FAULT_MINOR	2	no blocking operation to handle fault
 *	VM_FAULT_MAJOR	3	required blocking operation to handle fault
 */

-Will