From: Andi Kleen <ak@linux.intel.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Don Zickus <dzickus@redhat.com>,
dave.hansen@linux.intel.com, eranian@google.com,
jmario@redhat.com, linux-kernel@vger.kernel.org,
acme@infradead.org, mingo@kernel.org
Subject: Re: [PATCH] perf, x86: Optimize intel_pmu_pebs_fixup_ip()
Date: Wed, 16 Oct 2013 13:52:27 -0700 [thread overview]
Message-ID: <20131016205227.GJ7456@tassilo.jf.intel.com> (raw)
In-Reply-To: <20131016105755.GX10651@twins.programming.kicks-ass.net>
> So avoid having to call copy_from_user_nmi() for every instruction.
> Since we already limit the max basic block size, we can easily
> pre-allocate a piece of memory to copy the entire thing into in one
> go.
It would be better/more generic if you split copy_from_user_nmi() into
init() copy() end()
(and some state that checks if the underlying page changes)
Then first you don't need the buffer and it could be also
be applied to the other cases, like the stack unwinding,
where copying everything is likely too slow.
-Andi
next prev parent reply other threads:[~2013-10-16 20:52 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-14 20:35 x86, perf: throttling issues with long nmi latencies Don Zickus
2013-10-14 21:28 ` Andi Kleen
2013-10-15 10:14 ` Peter Zijlstra
2013-10-15 13:02 ` Peter Zijlstra
2013-10-15 14:32 ` Peter Zijlstra
2013-10-15 15:07 ` Peter Zijlstra
2013-10-15 15:41 ` Don Zickus
2013-10-16 10:57 ` [PATCH] perf, x86: Optimize intel_pmu_pebs_fixup_ip() Peter Zijlstra
2013-10-16 12:46 ` Don Zickus
2013-10-16 13:31 ` Peter Zijlstra
2013-10-16 13:54 ` Don Zickus
2013-10-17 11:21 ` Peter Zijlstra
2013-10-17 13:33 ` Peter Zijlstra
2013-10-29 14:07 ` [tip:perf/urgent] perf/x86: Fix NMI measurements tip-bot for Peter Zijlstra
2013-10-16 20:52 ` Andi Kleen [this message]
2013-10-16 21:03 ` [PATCH] perf, x86: Optimize intel_pmu_pebs_fixup_ip() Peter Zijlstra
2013-10-16 23:07 ` Peter Zijlstra
2013-10-17 9:41 ` Peter Zijlstra
2013-10-17 16:00 ` Don Zickus
2013-10-17 16:04 ` Don Zickus
2013-10-17 16:30 ` Peter Zijlstra
2013-10-17 18:26 ` Linus Torvalds
2013-10-17 21:08 ` Peter Zijlstra
2013-10-17 21:11 ` Peter Zijlstra
2013-10-17 22:01 ` Peter Zijlstra
2013-10-17 22:27 ` Linus Torvalds
2013-10-22 21:12 ` Peter Zijlstra
2013-10-23 7:09 ` Linus Torvalds
2013-10-23 20:48 ` Peter Zijlstra
2013-10-24 10:52 ` Peter Zijlstra
2013-10-24 13:47 ` Don Zickus
2013-10-24 14:06 ` Peter Zijlstra
2013-10-25 16:33 ` Don Zickus
2013-10-25 17:03 ` Peter Zijlstra
2013-10-26 10:36 ` Ingo Molnar
2013-10-28 13:19 ` Don Zickus
2013-10-29 14:08 ` [tip:perf/core] perf/x86: Further optimize copy_from_user_nmi() tip-bot for Peter Zijlstra
2013-10-23 7:44 ` [PATCH] perf, x86: Optimize intel_pmu_pebs_fixup_ip() Ingo Molnar
2013-10-17 14:49 ` Don Zickus
2013-10-17 14:51 ` Peter Zijlstra
2013-10-17 15:03 ` Don Zickus
2013-10-17 15:09 ` Peter Zijlstra
2013-10-17 15:11 ` Peter Zijlstra
2013-10-17 16:50 ` [tip:perf/core] perf/x86: " tip-bot for Peter Zijlstra
2013-10-15 16:22 ` x86, perf: throttling issues with long nmi latencies Don Zickus
2013-10-15 14:36 ` Don Zickus
2013-10-15 14:39 ` Peter Zijlstra
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