Re: [PATCH 3/6] 2.6.16-rc1 perfmon2 patch for review

[Greg KH <greg@kroah.com>]

On Wed, Jan 25, 2006 at 08:55:10PM -0800, Stephane Eranian wrote:
> Greg,
> 
> On Wed, Jan 25, 2006 at 03:52:04PM -0800, Greg KH wrote:
> > On Wed, Jan 25, 2006 at 12:08:13PM -0800, Bryan O'Sullivan wrote:
> > > On Tue, 2006-01-24 at 07:09 -0800, Stephane Eranian wrote:
> > > 
> > > > Because I tried regrouping all the /proc AND related interface into a single
> > > > C file.
> > > 
> > > sysctls seem to be every bit as deprecated as /proc for what you are
> > > tring to do.
> > > 
> > > > Well, it is not clear to me what criteria is used for /sys vs /proc.
> > > 
> > > My understanding is that only process-related stuff belongs in /proc
> > > now.  Other random cruft that has accumulated over the years is left
> > > there for backwards compatibility, but /sys interfaces are the way
> > > forward now.
> > 
> > Yes, that is exactly right.
> > 
> I don't have a problem moving the perfmon stuff to /sys, except for
> /proc/perfmon which is already being used by a bunch of tools. Unless
> we duplicate the information or use a simlink (if that's possible).

symlink will not work, sorry.

> Please indicate a location in the /sys tree where these would fit:
> 
> /proc/perfmon
> /proc/perfmon_map

What are the contents of these files?

> These are currently sysctl():
> 
> /proc/sys/kernel/perfmon/arg_size_max
> /proc/sys/kernel/perfmon/debug
> /proc/sys/kernel/perfmon/debug_ovfl
> /proc/sys/kernel/perfmon/expert_mode
> /proc/sys/kernel/perfmon/reset_stats
> /proc/sys/kernel/perfmon/smpl_buf_size_max
> /proc/sys/kernel/perfmon/sys_group
> /proc/sys/kernel/perfmon/task_group
> 

What are the contents of these different files?

Remember that sysfs is one value per file, so sysctls translate usually
very easily to sysfs files.

You can always just use /sys/kernel/perfmon/ if you like, as I don't
think you are bound to anything that would be in the /sys/devices tree
(you don't export per-cpu statistics, right?)

Hope this helps,

greg k-h