From: Peter Zijlstra <peterz@infradead.org>
To: Andi Kleen <ak@linux.intel.com>
Cc: Kyle Huey <me@kylehuey.com>,
Kan Liang <kan.liang@linux.intel.com>,
Ingo Molnar <mingo@kernel.org>,
Robert O'Callahan <robert@ocallahan.org>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Arnaldo Carvalho de Melo <acme@redhat.com>,
Jiri Olsa <jolsa@redhat.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Stephane Eranian <eranian@google.com>,
Thomas Gleixner <tglx@linutronix.de>,
Vince Weaver <vincent.weaver@maine.edu>,
acme@kernel.org, open list <linux-kernel@vger.kernel.org>
Subject: Re: [REGRESSION] x86, perf: counter freezing breaks rr
Date: Thu, 29 Nov 2018 16:35:26 +0100 [thread overview]
Message-ID: <20181129153526.GR2131@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20181127233615.GY13936@tassilo.jf.intel.com>
On Tue, Nov 27, 2018 at 03:36:15PM -0800, Andi Kleen wrote:
> > It does seem that FREEZE_PERFMON_ON_PMI (misnamed as it is) is of
> > rather limited use (or even negative, in our case) to a counter that's
> > already restricted to ring 3.
>
> It's much faster. The PMI cost goes down dramatically.
faster doesn't mean much when its broken.
prev parent reply other threads:[~2018-11-29 15:35 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-20 16:19 [REGRESSION] x86, perf: counter freezing breaks rr Kyle Huey
2018-11-20 17:08 ` Peter Zijlstra
2018-11-20 17:59 ` [tip:perf/urgent] perf/x86/intel: Fix regression by default disabling perfmon v4 interrupt handling tip-bot for Peter Zijlstra
2018-11-20 18:20 ` [REGRESSION] x86, perf: counter freezing breaks rr Stephane Eranian
2018-11-20 19:50 ` Kyle Huey
2018-11-20 19:41 ` Andi Kleen
2018-11-20 19:54 ` Kyle Huey
2018-11-20 20:11 ` Andi Kleen
2018-11-20 20:53 ` Kyle Huey
2018-11-20 21:18 ` Andi Kleen
2018-11-20 21:46 ` Kyle Huey
2018-11-20 22:19 ` Andi Kleen
2018-11-20 21:19 ` Stephane Eranian
2018-11-20 21:34 ` Kyle Huey
2018-11-20 22:16 ` Peter Zijlstra
2018-11-20 22:25 ` Peter Zijlstra
2018-11-20 22:38 ` Andi Kleen
2018-11-21 8:14 ` Peter Zijlstra
2018-11-27 22:08 ` Kyle Huey
2018-11-27 23:36 ` Andi Kleen
2018-11-28 1:25 ` Stephane Eranian
2018-11-29 14:50 ` Liang, Kan
2018-11-29 15:35 ` Peter Zijlstra [this message]
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