From: Joe Mario <jmario@redhat.com>
To: Andi Kleen <andi@firstfloor.org>
Cc: Don Zickus <dzickus@redhat.com>,
Davidlohr Bueso <davidlohr@hp.com>,
acme@ghostprotocols.net, LKML <linux-kernel@vger.kernel.org>,
jolsa@redhat.com, fowles@inreach.com, eranian@google.com,
Arnaldo Carvalho de Melo <acme@redhat.com>,
David Ahern <dsahern@gmail.com>,
Frederic Weisbecker <fweisbec@gmail.com>,
Mike Galbraith <efault@gmx.de>, Paul Mackerras <paulus@samba.org>,
Peter Zijlstra <peterz@infradead.org>,
Richard Fowles <rfowles@redhat.com>
Subject: Re: [PATCH 08/19] perf c2c: Shared data analyser
Date: Mon, 03 Mar 2014 13:07:00 -0500 [thread overview]
Message-ID: <5314C4C4.1020304@redhat.com> (raw)
In-Reply-To: <20140303172316.GA22728@two.firstfloor.org>
On 03/03/2014 12:23 PM, Andi Kleen wrote:
>> Hmm, so based on Andi's reply, I am assuming you are running on a Westmere
>> (or Nehalem) due to the lack of mem-stores.
>>
>> If you don't have mem-stores, this tool isn't going to work. The tool can
>> only detect contention when sampling reads _and_ writes to the same
>> addresses.
>
> On these CPUs you could simply sample on HITM. You won't get addresses,
> but at least IPs and call stacks.
>
> -Andi
>
If you only sample on the HITMs then you don't get the store misses. That means you'll not be able to detect who is simultaneously tugging on the same cache lines. That gives up much of the value of "perf c2c".
As we developed this, we ended up settling on Ivy Bridge to get the behavior we wanted.
Joe
next prev parent reply other threads:[~2014-03-03 18:07 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-28 17:42 [PATCH 00/19 V2] perf, c2c: Add new tool to analyze cacheline contention on NUMA systems Don Zickus
2014-02-28 17:42 ` [PATCH 01/19] Revert "perf: Disable PERF_RECORD_MMAP2 support" Don Zickus
2014-02-28 17:42 ` [PATCH 02/19] perf, sort: Add physid sorting based on mmap2 data Don Zickus
2014-03-19 10:45 ` Jiri Olsa
2014-03-19 13:36 ` Don Zickus
2014-02-28 17:42 ` [PATCH 03/19] perf, sort: Allow unique sorting instead of combining hist_entries Don Zickus
2014-02-28 17:42 ` [PATCH 04/19] perf: Allow ability to map cpus to nodes easily Don Zickus
2014-03-19 12:48 ` Jiri Olsa
2014-03-19 13:38 ` Don Zickus
2014-03-19 13:22 ` Jiri Olsa
2014-02-28 17:42 ` [PATCH 05/19] perf, kmem: Utilize the new generic cpunode_map Don Zickus
2014-02-28 17:42 ` [PATCH 06/19] perf: Fix stddev calculation Don Zickus
2014-02-28 17:42 ` [PATCH 07/19] perf, callchain: Add generic callchain print handler for stdio Don Zickus
2014-02-28 17:42 ` [PATCH 08/19] perf c2c: Shared data analyser Don Zickus
2014-02-28 19:08 ` Andi Kleen
2014-02-28 19:46 ` Don Zickus
2014-02-28 21:03 ` Davidlohr Bueso
2014-02-28 22:28 ` Joe Mario
2014-03-01 0:50 ` Andi Kleen
2014-03-03 14:13 ` Don Zickus
2014-03-03 15:05 ` Don Zickus
2014-03-03 17:23 ` Andi Kleen
2014-03-03 18:07 ` Joe Mario [this message]
2014-03-03 18:41 ` Peter Zijlstra
2014-03-03 18:58 ` Andi Kleen
2014-03-03 19:48 ` Peter Zijlstra
2014-03-03 20:32 ` Don Zickus
2014-03-03 21:38 ` Andi Kleen
2014-03-03 21:41 ` Don Zickus
2014-03-03 20:30 ` Don Zickus
2014-03-03 20:26 ` Don Zickus
2014-03-03 21:36 ` Andi Kleen
2014-03-04 9:42 ` Peter Zijlstra
2014-03-03 18:21 ` Davidlohr Bueso
2014-02-28 17:42 ` [PATCH 09/19] perf c2c: Dump raw records, decode data_src bits Don Zickus
2014-02-28 17:42 ` [PATCH 10/19] perf, c2c: Rework setup code to prepare for features Don Zickus
2014-02-28 17:43 ` [PATCH 11/19] perf, c2c: Add in sort on physid Don Zickus
2014-02-28 18:59 ` Andi Kleen
2014-02-28 19:44 ` Don Zickus
2014-03-01 1:07 ` Andi Kleen
2014-03-01 1:27 ` Namhyung Kim
2014-02-28 17:43 ` [PATCH 12/19] perf, c2c: Add stats to track data source bits and cpu to node maps Don Zickus
2014-02-28 17:43 ` [PATCH 13/19] perf, c2c: Sort based on hottest cache line Don Zickus
2014-02-28 17:43 ` [PATCH 14/19] perf, c2c: Display cacheline HITM analysis to stdout Don Zickus
2014-02-28 17:43 ` [PATCH 15/19] perf, c2c: Add callchain support Don Zickus
2014-03-19 13:00 ` Jiri Olsa
2014-03-19 13:53 ` Don Zickus
2014-03-19 14:05 ` Jiri Olsa
2014-02-28 17:43 ` [PATCH 16/19] perf, c2c: Output summary stats Don Zickus
2014-02-28 17:43 ` [PATCH 17/19] perf, c2c: Dump rbtree for debugging Don Zickus
2014-02-28 17:43 ` [PATCH 18/19] perf, c2c: Add symbol count table Don Zickus
2014-02-28 17:43 ` [PATCH 19/19] perf, c2c: Add shared cachline summary table Don Zickus
2014-02-28 18:57 ` [PATCH 00/19 V2] perf, c2c: Add new tool to analyze cacheline contention on NUMA systems Andi Kleen
2014-02-28 19:42 ` Don Zickus
2014-02-28 21:54 ` Andi Kleen
2014-03-03 14:04 ` Don Zickus
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