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From: Frederic Weisbecker <fweisbec@gmail.com>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: LKML <linux-kernel@vger.kernel.org>, Ingo Molnar <mingo@elte.hu>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Jason Wessel <jason.wessel@windriver.com>,
	Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH 3/6] x86: Allow the user not to build hw_breakpoints
Date: Wed, 27 Apr 2011 21:50:07 +0200	[thread overview]
Message-ID: <20110427195004.GA3654@nowhere> (raw)
In-Reply-To: <008d59a3-bd23-4cb3-8a73-1640137e3ac4@email.android.com>

On Wed, Apr 27, 2011 at 11:54:17AM -0700, H. Peter Anvin wrote:
> Why do you have to be able to disable breakpoints to disable perf? That seems seriously backwards, especially since we had breakpoints long before perf...

That started when we implemented breakpoints as counters. Then we realized that
ptrace had its own scheduling that was somehow duplicating what perf was doing.
So we have finally unified that under perf. The good point is that archs don't need
to care much about ptrace breakpoints tracking, just the interface.

But yeah the bad point is that dependency.

  parent reply	other threads:[~2011-04-27 19:50 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-04-27 16:59 [PATCH 0/6] hw_breakpoint: Let the user choose not to build it (and perf too) Frederic Weisbecker
2011-04-27 16:59 ` [PATCH 1/6] hw_breakpoints: Split hardware breakpoints config Frederic Weisbecker
2011-04-27 16:59 ` [PATCH 2/6] hw_breakpoints: Migrate breakpoint conditional build under new config Frederic Weisbecker
2011-04-27 16:59 ` [PATCH 3/6] x86: Allow the user not to build hw_breakpoints Frederic Weisbecker
2011-04-27 17:38   ` H. Peter Anvin
2011-04-27 18:26     ` Frederic Weisbecker
2011-04-27 19:10       ` Michael Bohan
     [not found]       ` <008d59a3-bd23-4cb3-8a73-1640137e3ac4@email.android.com>
2011-04-27 19:50         ` Frederic Weisbecker [this message]
2011-05-03 15:35           ` H. Peter Anvin
2011-05-03 23:12             ` Frederic Weisbecker
2011-05-03 23:40               ` H. Peter Anvin
2011-05-03 23:54                 ` Frederic Weisbecker
2011-05-03 23:56                   ` H. Peter Anvin
2011-05-04  0:13                     ` Frederic Weisbecker
2011-04-27 17:00 ` [PATCH 4/6] hw_breakpoints: Breakpoints arch ability don't need perf events Frederic Weisbecker
2011-04-27 17:00 ` [PATCH 5/6] hw_breakpoints: Only force perf events if breakpoints are selected Frederic Weisbecker
2011-04-27 17:00 ` [PATCH 6/6] hw_breakpoints: Drop remaining misplaced dependency on perf Frederic Weisbecker
2011-04-27 17:02 ` [PATCH 0/6] hw_breakpoint: Let the user choose not to build it (and perf too) Frederic Weisbecker
2011-05-03 11:40 ` Will Deacon
  -- strict thread matches above, loose matches on Subject: below --
2011-05-24 21:52 [PATCH v2] " Frederic Weisbecker
2011-05-24 21:52 ` [PATCH 3/6] x86: Allow the user not to build hw_breakpoints Frederic Weisbecker
2011-07-14 15:03 [GIT PULL] hw_breakpoints updates Frederic Weisbecker
2011-07-14 15:03 ` [PATCH 3/6] x86: Allow the user not to build hw_breakpoints Frederic Weisbecker
2011-07-14 21:26   ` H. Peter Anvin
2011-07-14 21:51     ` Frederic Weisbecker
2011-07-21  7:26     ` Ingo Molnar
2011-07-21 12:36       ` Peter Zijlstra
2011-07-21 13:03       ` Frederic Weisbecker

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