From: David Ahern <dsahern@gmail.com>
To: Stephane Eranian <eranian@google.com>
Cc: Ingo Molnar <mingo@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
"mingo@elte.hu" <mingo@elte.hu>,
"ak@linux.intel.com" <ak@linux.intel.com>,
Arnaldo Carvalho de Melo <acme@redhat.com>,
Jiri Olsa <jolsa@redhat.com>, Hugh Dickins <hughd@google.com>
Subject: Re: [RFC] perf: mmap2 not covering VM_CLONE regions
Date: Tue, 08 Oct 2013 13:57:43 -0600 [thread overview]
Message-ID: <525463B7.3030203@gmail.com> (raw)
In-Reply-To: <CABPqkBTibSKs9qG_RARn2+vrHb6VODN9N9BPGSv_MAQEXZcGmw@mail.gmail.com>
On 10/8/13 1:54 PM, Stephane Eranian wrote:
>>> If the current MMAP2 is not a complete solution for what you (Google)
>>> need, should support be reverted before 3.12 is released? No sense in
>>> making this part of the forever API if more work is needed on it.
>>
>> Instead of a full revert we could just turn off the ABI portion minimally
>> and not recognize it for now. Assuming a more complete solution is in the
>> works for v3.13.
>>
> That's a possibility. They are also pieces in the perf tool itself.
> We could certainly make the attr->mmap2 bit disappear.
>
> I think it boils down to how can we uniquely identify virtual
> mapping to the same physical data either via shmat(), files, VM_CLONE.
> We had all covered but the last case with the ino approach. We don't have
> a solution for VM_CLONE yet.
>
I was mainly thinking the 2 parts that generate MMAP2 events: kernel
side it's the mmap2 attribute and perf_event_mmap_output; userspace side
it's perf_event__synthesize_mmap_event. Certainly the rest of the
plumbing can be left in place until the solution is refined as needed.
David
next prev parent reply other threads:[~2013-10-08 19:57 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-30 15:44 [RFC] perf: mmap2 not covering VM_CLONE regions Stephane Eranian
2013-09-30 16:15 ` Peter Zijlstra
2013-09-30 16:48 ` Stephane Eranian
2013-09-30 16:54 ` Peter Zijlstra
2013-10-01 11:22 ` Stephane Eranian
2013-10-02 11:23 ` Peter Zijlstra
2013-10-02 11:58 ` Peter Zijlstra
2013-10-02 12:39 ` Ingo Molnar
2013-10-02 12:46 ` Peter Zijlstra
2013-10-02 12:59 ` Stephane Eranian
2013-10-02 13:01 ` Peter Zijlstra
2013-10-02 13:13 ` Stephane Eranian
2013-10-02 13:37 ` Peter Zijlstra
2013-10-02 17:14 ` Kees Cook
2013-10-02 17:20 ` Stephane Eranian
2013-10-02 17:29 ` Kees Cook
2013-10-02 17:49 ` Stephane Eranian
2013-10-02 18:10 ` Kees Cook
2013-10-02 19:00 ` Peter Zijlstra
2013-10-02 19:38 ` Kees Cook
2013-10-02 20:31 ` Peter Zijlstra
2013-10-03 8:55 ` Stephane Eranian
2013-10-03 9:03 ` Peter Zijlstra
2013-10-03 9:13 ` Stephane Eranian
2013-10-03 15:34 ` Kees Cook
2013-10-07 21:04 ` Stephane Eranian
2013-10-08 6:54 ` Peter Zijlstra
2013-10-08 7:15 ` Stephane Eranian
2013-10-08 9:36 ` Peter Zijlstra
2013-10-08 9:42 ` Stephane Eranian
2013-10-08 9:54 ` Peter Zijlstra
2013-10-03 18:32 ` Andi Kleen
2013-10-07 11:16 ` Stephane Eranian
2013-10-07 11:32 ` Peter Zijlstra
2013-10-02 15:22 ` Ingo Molnar
2013-10-08 14:23 ` David Ahern
2013-10-08 19:41 ` Ingo Molnar
2013-10-08 19:54 ` Stephane Eranian
2013-10-08 19:57 ` David Ahern [this message]
2013-10-09 9:54 ` Ingo Molnar
2013-10-09 9:59 ` Ingo Molnar
2013-10-09 10:39 ` Peter Zijlstra
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=525463B7.3030203@gmail.com \
--to=dsahern@gmail.com \
--cc=acme@redhat.com \
--cc=ak@linux.intel.com \
--cc=eranian@google.com \
--cc=hughd@google.com \
--cc=jolsa@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=mingo@kernel.org \
--cc=peterz@infradead.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).