From: Robert Richter <robert.richter@amd.com>
To: Andi Kleen <andi@firstfloor.org>
Cc: "Ingo Molnar" <mingo@elte.hu>,
"Peter Zijlstra" <a.p.zijlstra@chello.nl>,
"Frédéric Weisbecker" <fweisbec@gmail.com>,
"Mike Galbraith" <efault@gmx.de>,
LKML <linux-kernel@vger.kernel.org>,
"Arnaldo Carvalho de Melo" <acme@redhat.com>,
"Pekka Enberg" <penberg@cs.helsinki.fi>,
"Paul Mackerras" <paulus@samba.org>,
oprofile-list <oprofile-list@lists.sourceforge.net>,
"H. Peter Anvin" <hpa@zytor.com>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Linus Torvalds" <torvalds@linux-foundation.org>,
"Arjan van de Ven" <arjan@infradead.org>,
"Steven Rostedt" <rostedt@goodmis.org>
Subject: Re: [PATCH 0/26] oprofile: Performance counter multiplexing
Date: Fri, 5 Mar 2010 17:46:15 +0100 [thread overview]
Message-ID: <20100305164615.GY13205@erda.amd.com> (raw)
In-Reply-To: <87ocjcqcdj.fsf@basil.nowhere.org>
On 26.02.10 15:51:04, Andi Kleen wrote:
> That said the biggest problem with oprofile right now that the
> new buffer it's using is quite a lot less reliable and drops
> events left and right on any non trivial load. That makes
> oprofile very unreliable, especially in call graph mode.
(cc'ing Steve)
Andi,
the tests I run with oprofile do not indicate unreliable ring_buffer
behavior. Maybe my use cases and loads are different. Can you describe
a setup where this may happen for sure? What is the impact, do you
have lost samples or inconsistent buffer data? Is the data loss in
kernel or user space? Also, I am not aware that the ring_buffer is
unreliable for ftrace or tracepoints, where it is heavily used. I
really want to find the root cause here.
Thanks,
-Robert
--
Advanced Micro Devices, Inc.
Operating System Research Center
email: robert.richter@amd.com
next prev parent reply other threads:[~2010-03-05 16:46 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-07-28 17:07 [PATCH 0/26] oprofile: Performance counter multiplexing Robert Richter
2009-07-28 17:07 ` [PATCH 01/26] x86/oprofile: Rework and simplify nmi_cpu_setup() Robert Richter
2009-07-28 17:07 ` [PATCH 02/26] x86/oprofile: Whitespaces changes only Robert Richter
2009-07-28 17:07 ` [PATCH 03/26] oprofile: Implement performance counter multiplexing Robert Richter
2009-07-28 17:07 ` [PATCH 04/26] x86/oprofile: Fix usage of NUM_CONTROLS/NUM_COUNTERS macros Robert Richter
2009-07-28 17:07 ` [PATCH 05/26] x86/oprofile: Use per_cpu() instead of __get_cpu_var() Robert Richter
2009-07-28 17:07 ` [PATCH 06/26] x86/oprofile: Fix initialization of switch_index Robert Richter
2009-07-28 17:07 ` [PATCH 07/26] oprofile: oprofile_set_timeout(), return with error for invalid args Robert Richter
2009-07-28 17:07 ` [PATCH 08/26] oprofile: Rename variable timeout_jiffies and move to oprofile_files.c Robert Richter
2009-07-28 17:07 ` [PATCH 09/26] oprofile: Remove oprofile_multiplexing_init() Robert Richter
2009-07-28 17:07 ` [PATCH 10/26] oprofile: Grouping multiplexing code in oprof.c Robert Richter
2009-07-28 17:07 ` [PATCH 11/26] oprofile: Introduce op_x86_phys_to_virt() Robert Richter
2009-07-28 17:07 ` [PATCH 12/26] oprofile: Grouping multiplexing code in op_model_amd.c Robert Richter
2009-07-28 17:07 ` [PATCH 13/26] x86/oprofile: Implement multiplexing setup/shutdown functions Robert Richter
2009-07-28 17:07 ` [PATCH 14/26] x86/oprofile: Moving nmi_setup_cpu_mux() in nmi_int.c Robert Richter
2009-07-28 17:07 ` [PATCH 15/26] x86/oprofile: Moving nmi_cpu_save/restore_mpx_registers() " Robert Richter
2009-07-28 17:07 ` [PATCH 16/26] x86/oprofile: Moving nmi_cpu_switch() " Robert Richter
2009-07-28 17:07 ` [PATCH 17/26] x86/oprofile: Remove const qualifier from struct op_x86_model_spec Robert Richter
2009-07-28 17:07 ` [PATCH 18/26] x86/oprofile: Remove unused num_virt_controls " Robert Richter
2009-07-28 17:07 ` [PATCH 19/26] x86/oprofile: Modify initialization of num_virt_counters Robert Richter
2009-07-28 17:07 ` [PATCH 20/26] x86/oprofile: Add function has_mux() to check multiplexing support Robert Richter
2009-07-28 17:07 ` [PATCH 21/26] x86/oprofile: Enable multiplexing only if the model supports it Robert Richter
2009-07-28 17:07 ` [PATCH 22/26] x86/oprofile: Implement mux_clone() Robert Richter
2009-07-28 17:07 ` [PATCH 23/26] oprofile: Adding switch counter to oprofile statistic variables Robert Richter
2009-07-28 17:07 ` [PATCH 24/26] x86/oprofile: Implement op_x86_virt_to_phys() Robert Richter
2009-07-28 17:07 ` [PATCH 25/26] x86/oprofile: Add counter reservation check for virtual counters Robert Richter
2009-07-28 17:07 ` [PATCH 26/26] x86/oprofile: Small coding style fixes Robert Richter
2009-07-28 18:45 ` [PATCH 0/26] oprofile: Performance counter multiplexing Andi Kleen
2009-07-28 22:18 ` Suthikulpanit, Suravee
2009-08-03 11:22 ` Ingo Molnar
2009-08-03 14:25 ` Arjan van de Ven
2009-08-04 20:11 ` Ingo Molnar
2009-08-05 12:35 ` Robert Richter
2009-08-06 7:31 ` Pekka Enberg
2009-08-06 10:51 ` Ingo Molnar
2009-08-13 16:13 ` Robert Richter
[not found] ` <20090806105134.GD11236__37984.4768475325$1249556453$gmane$org@elte.hu>
2010-02-26 14:51 ` Andi Kleen
2010-03-05 16:46 ` Robert Richter [this message]
2010-03-05 17:01 ` Steven Rostedt
2010-03-08 3:51 ` Andi Kleen
2009-08-03 16:30 ` Robert Richter
2009-08-04 17:05 ` Ingo Molnar
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