On Tue, 2007-08-28 at 15:13 -0700, Nish Aravamudan wrote:

On 8/28/07, Christoph Lameter [off-list ref] wrote:

quoted

On Tue, 28 Aug 2007, Lee Schermerhorn wrote:

quoted

I thought I'd give it a try, but thinking that /proc variables were
discouraged, where else but sysfs to put them.  A class attribute
to /sys/devices/system/node seemed like the appropriate place.

Right. That is the right place.

quoted

I'm not wedded to this interface.  However, I realy don't think it's
worth doing as multiple files.

I think one single file per nodemask makes sense. Otherwise files become
difficult to parse. I just forgot....

quoted

its executed, in the grand scheme of things.  However, I must admit that
I've become addicted to the ease with which one can write one-off
scripts to query configuration/statistics, tune/modify behavior or
trigger actions via just cat'ing from and/or echo'ing to a /proc or /sys
file.

So, where to go with this patch?  Drop it?  Leave it as is?  Move
it /proc so that it can be a single file?   Make it multiple files in
sysfs?  Putting it as politely as possible, the last is not my favorite
option, but if folks think this info is useful and that's the way to go,
so be it.  And what about mask vs list?  It's a 4 character change in
the code to go either way.

I would suggest to do the one file thing in sysfs and use the function
that already exists in the kernel to print the nice nodelists. Using the
nice function is just calling another function since the code is already
there.

At some point we may even allow changing the nodemasks. One could imagine
that we would add nodemasks that allow use of hugepages on certain nodes
or the slab allocator to allocate on certain nodes.

Just to chime in here -- I've been on vacation for a bit recently -- I
fully support the one-value per file rule for sysfs. I think it makes
things a bit clearer. I like this attribute as well, and the idea of
expanding it down the road is easiest if we use one file per-nodemask.

Welcome back, Nish.

OK, I relent.  I'll respin with one file per state.  I'll go with a
slight modification to the names suggested by Yasunori-san:

possible, online, has_memory, has_cpu

Some come, mon...

Lee

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