From: Andi Kleen <andi@firstfloor.org>
To: Chris Freehill <cfreehill@utexas.edu>
Cc: Andi Kleen <andi@firstfloor.org>, linux-perf-users@vger.kernel.org
Subject: Re: perf uncore behavior
Date: Sat, 2 May 2015 14:16:11 +0200 [thread overview]
Message-ID: <20150502121611.GK2366@two.firstfloor.org> (raw)
In-Reply-To: <CANFySvcwE52VTqPKc5vzkQkq+wAenFr=deaGX8ZxGQFTU1SjVg@mail.gmail.com>
On Fri, May 01, 2015 at 09:31:58PM -0500, Chris Freehill wrote:
> A follow up...can you define what "sockets/nodes" means in this
> context? What is the relationship between sockets/nodes and CPU's.
In Linux terminology a CPU is a logical CPU thread. A socket
is a physical chip.
> What is the distinction? For core events, they would be the same,
> right? Could you give an example of what "-a" would sum up when we are
> talking about uncore events?
It sums up events from all sockets
>
> I think my main confusion is an assumption (up to now, anyway) that
> there is only one set of uncore events, for the multicore device, so
> it wouldn't make sense to sum up anything.
There is one set per socket (or rather chip, if you talk about an
multi-chip-module)
> For core events, my
> understanding is that with no "-C<core id>" specified, perf sums up
> the core event counts and presents this as output. For uncore, the
> events are not per-core, so I'm not sure how to interpret that "sum".
It's the sum of all cores on that socket.
-Andi
prev parent reply other threads:[~2015-05-02 12:16 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-01 20:55 perf uncore behavior Chris Freehill
2015-05-02 1:40 ` Andi Kleen
2015-05-02 2:31 ` Chris Freehill
2015-05-02 12:16 ` Andi Kleen [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20150502121611.GK2366@two.firstfloor.org \
--to=andi@firstfloor.org \
--cc=cfreehill@utexas.edu \
--cc=linux-perf-users@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.