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, 4 May 2011 01:12:43 +0200 [thread overview]
Message-ID: <20110503231241.GG2678@nowhere> (raw)
In-Reply-To: <4DC020D9.3050000@zytor.com>
On Tue, May 03, 2011 at 08:35:53AM -0700, H. Peter Anvin wrote:
> On 04/27/2011 12:50 PM, Frederic Weisbecker wrote:
> > 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.
>
> It really is very bad... without breakpoints, you lose almost all
> debugging support.
Right, so it should be fine for embedded environment to disable breakpoints.
It depends on CONFIG_EXPERT now.
next prev parent reply other threads:[~2011-05-03 23:12 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
2011-05-03 15:35 ` H. Peter Anvin
2011-05-03 23:12 ` Frederic Weisbecker [this message]
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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