From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: eranian@gmail.com
Cc: Ingo Molnar <mingo@elte.hu>, LKML <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
Robert Richter <robert.richter@amd.com>,
Paul Mackerras <paulus@samba.org>,
Andi Kleen <andi@firstfloor.org>,
Maynard Johnson <mpjohn@us.ibm.com>, Carl Love <cel@us.ibm.com>,
Corey J Ashford <cjashfor@us.ibm.com>,
Philip Mucci <mucci@eecs.utk.edu>,
Dan Terpstra <terpstra@eecs.utk.edu>,
perfmon2-devel <perfmon2-devel@lists.sourceforge.net>
Subject: Re: perf_counters issue with self-sampling threads
Date: Mon, 27 Jul 2009 18:56:41 +0200 [thread overview]
Message-ID: <1248713801.6987.1684.camel@twins> (raw)
In-Reply-To: <7c86c4470907270951i48886d56g90bc198f26bb0716@mail.gmail.com>
On Mon, 2009-07-27 at 18:51 +0200, stephane eranian wrote:
> Hi,
>
> I believe there is a problem with the current perf_counters (PCL)
> code for self-sampling threads. The problem is related to sample
> notifications via signal.
>
> PCL (just like perfmon) is using SIGIO, an asynchronous signal,
> to notify user applications of the availability of data in the event
> buffer.
>
> POSIX does not mandate that asynchronous signals be delivered
> to the thread in which they originated. Any thread in the process
> may process the signal, assuming it does not have the signal
> blocked.
Bugger, you're right. /me kicks POSIX again for creating these crazy ass
semantics.
I'll look at fixing this.
Thanks!
next prev parent reply other threads:[~2009-07-27 16:54 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-07-27 16:51 perf_counters issue with self-sampling threads stephane eranian
2009-07-27 16:56 ` Peter Zijlstra [this message]
2009-07-27 21:25 ` Andi Kleen
[not found] ` <7c86c4470907272213w2ee57080re50dd22a4d73a7e0@mail.gmail.com>
2009-07-28 8:51 ` stephane eranian
2009-07-28 8:56 ` Andi Kleen
2009-07-28 9:13 ` stephane eranian
2009-08-04 16:09 ` stephane eranian
2009-07-29 12:19 ` Peter Zijlstra
2009-07-29 12:37 ` stephane eranian
2009-07-29 12:46 ` Peter Zijlstra
2009-07-29 22:17 ` Oleg Nesterov
2009-07-30 11:31 ` Peter Zijlstra
2009-07-30 19:20 ` Oleg Nesterov
2009-07-30 20:00 ` Peter Zijlstra
2009-07-30 20:28 ` Oleg Nesterov
2009-07-30 21:09 ` stephane eranian
2009-07-31 8:35 ` [RFC][PATCH] fcntl: F_[SG]ETOWN_TID Peter Zijlstra
2009-07-31 14:01 ` stephane eranian
2009-07-31 20:52 ` Oleg Nesterov
2009-07-31 21:11 ` Andrew Morton
2009-08-01 1:27 ` [PATCH 0/2] send_sigio/do_send_sig_info (Was: [RFC][PATCH] fcntl: F_[SG]ETOWN_TID) Oleg Nesterov
2009-08-03 15:48 ` [PATCH 3/2] fcntl: F_[SG]ETOWN_TID Peter Zijlstra
2009-08-03 17:16 ` Oleg Nesterov
2009-08-03 17:47 ` Peter Zijlstra
2009-08-03 18:06 ` Oleg Nesterov
2009-08-03 18:36 ` Peter Zijlstra
2009-08-03 19:02 ` Oleg Nesterov
2009-08-04 11:39 ` [PATCH 3/2 -v3] fcntl: F_[SG]ETOWN_EX Peter Zijlstra
2009-08-04 16:20 ` Oleg Nesterov
2009-08-04 16:52 ` Peter Zijlstra
2009-08-04 17:19 ` Oleg Nesterov
2009-08-06 13:14 ` [PATCH 3/2 -v4] " Peter Zijlstra
2009-08-06 19:05 ` Oleg Nesterov
2009-08-07 12:10 ` stephane eranian
2009-08-01 1:28 ` [PATCH 1/2] signals: introduce do_send_sig_info() helper Oleg Nesterov
2009-08-01 1:28 ` [PATCH 2/2] signals: send_sigio: use do_send_sig_info() to avoid check_kill_permission() Oleg Nesterov
2009-08-03 12:53 ` [RFC][PATCH] fcntl: F_[SG]ETOWN_TID stephane eranian
2009-08-09 5:46 ` F_SETOWN_TID: F_SETOWN was thread-specific for a while Jamie Lokier
2009-08-10 12:22 ` stephane eranian
2009-08-10 17:03 ` Oleg Nesterov
2009-08-10 21:01 ` stephane eranian
2009-08-17 17:16 ` Oleg Nesterov
2009-08-17 17:40 ` Oleg Nesterov
2009-08-17 22:26 ` stephane eranian
2009-08-18 11:45 ` Oleg Nesterov
2009-08-20 10:00 ` stephane eranian
2009-08-11 13:10 ` Jamie Lokier
2009-08-17 17:05 ` Oleg Nesterov
2009-08-03 15:21 ` [RFC][PATCH] fcntl: F_[SG]ETOWN_TID Peter Zijlstra
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