From: Andi Kleen <andi@firstfloor.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Andi Kleen <andi@firstfloor.org>,
kan.liang@intel.com, eranian@google.com, acme@infradead.org,
linux-kernel@vger.kernel.org, Andi Kleen <ak@linux.intel.com>
Subject: Re: [PATCH 2/9] x86, perf: Add support for PEBSv3 profiling
Date: Fri, 8 May 2015 13:59:54 +0200 [thread overview]
Message-ID: <20150508115954.GT2366@two.firstfloor.org> (raw)
In-Reply-To: <20150508105958.GD27504@twins.programming.kicks-ass.net>
> That's wrong. It does not respect perf_event_attr::clock_id.
Ok.
Are we really defaulting to real time now? (CLOCK_REALTIME == 0)
What happens when ntpd is active and lets the time drift? That
sounds very bad for event accuracy.
The clockid patch looks broken to me. At least it should default
to MONOTONIC time, not just the time that happens to be 0 by
accident.
Also I question we really need that many different kinds of
time stamps.
-Andi
--
ak@linux.intel.com -- Speaking for myself only.
next prev parent reply other threads:[~2015-05-08 12:00 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-07 22:56 perf: Add basic Skylake PMU support Andi Kleen
2015-05-07 22:56 ` [PATCH 1/9] x86: Add a native_perf_sched_clock_from_tsc Andi Kleen
2015-05-07 22:56 ` [PATCH 2/9] x86, perf: Add support for PEBSv3 profiling Andi Kleen
2015-05-08 10:59 ` Peter Zijlstra
2015-05-08 11:59 ` Andi Kleen [this message]
2015-05-08 12:06 ` Peter Zijlstra
2015-05-07 22:56 ` [PATCH 3/9] x86: Add new MSRs and MSR bits used for Skylake perfmon Andi Kleen
2015-05-07 22:56 ` [PATCH 4/9] perf: Add cycles to branch_info Andi Kleen
2015-05-07 22:56 ` [PATCH 5/9] x86, perf: Add support for LBRv5 Andi Kleen
2015-05-07 22:56 ` [PATCH 6/9] x86, perf: Add Skylake support Andi Kleen
2015-05-07 22:56 ` [PATCH 7/9] perf, x86: Handle new status bits Andi Kleen
2015-05-07 22:56 ` [PATCH 8/9] perf, x86: Optimize v4 LBR unfreezing Andi Kleen
2015-05-08 11:19 ` Peter Zijlstra
2015-05-07 22:56 ` [PATCH 9/9] perf, tools: Add tools support for cycles, weight branch_info field Andi Kleen
-- strict thread matches above, loose matches on Subject: below --
2015-05-10 19:22 perf: Add basic Skylake PMU support v2 Andi Kleen
2015-05-10 19:22 ` [PATCH 2/9] x86, perf: Add support for PEBSv3 profiling Andi Kleen
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