From: Byungchul Park <byungchul.park@lge.com>
To: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>,
Ingo Molnar <mingo@kernel.org>,
peterz@infradead.org, linux-kernel@vger.kernel.org,
walken@google.com, Peter Zijlstra <a.p.zijlstra@chello.nl>
Subject: Re: [PATCH 1/2] x86/dumpstack: Optimize save_stack_trace
Date: Tue, 19 Jul 2016 09:08:01 +0900 [thread overview]
Message-ID: <20160719000801.GS2279@X58A-UD3R> (raw)
In-Reply-To: <20160718130910.vmyvadh5arurxptv@treble>
On Mon, Jul 18, 2016 at 08:09:10AM -0500, Josh Poimboeuf wrote:
> > > > There are several different users of save_stack_trace() in the kernel, we can't
> > > > be sure that all of them are interested in dropping those guesses.
> > > >
> > > > So I'd rather advocate in favour of a new seperate helper.
> > >
> > > So how about we change save_stack_trace() to use print_context_stack()
> > > for CONFIG_FRAME_POINTER=n and print_context_stack_bp() for
> > > CONFIG_FRAME_POINTER=y? That would preserve the existing behavior, no?
> >
> > Even if CONFIG_FRAME_POINTER=y, someone may want to guess, doesn't they?
>
> For CONFIG_FRAME_POINTER=y, the guesses are ignored by
> __save_stack_address() and only the reliable addresses are saved.
Indeed. I was confused.
> We shouldn't change that behavior, unless you actually know of a caller
> who wants the guesses. And even then the "guess" variation should be
> named accordingly to make it clear that it's not a "reliable" stack
> trace, even though frame pointers are enabled.
My question was caused by being confused. I agree with you.
>
> --
> Josh
next prev parent reply other threads:[~2016-07-19 0:10 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-04 10:27 [PATCH 1/2] x86/dumpstack: Optimize save_stack_trace Byungchul Park
2016-07-04 10:27 ` [PATCH 2/2] x86/dumpstack: Add save_stack_trace_norm() Byungchul Park
2016-07-07 10:17 ` [PATCH 1/2] x86/dumpstack: Optimize save_stack_trace Byungchul Park
2016-07-08 10:08 ` Ingo Molnar
2016-07-08 14:29 ` Josh Poimboeuf
2016-07-08 14:48 ` Ingo Molnar
2016-07-08 15:02 ` Frederic Weisbecker
2016-07-08 15:22 ` Josh Poimboeuf
2016-07-18 3:14 ` Byungchul Park
2016-07-18 13:09 ` Josh Poimboeuf
2016-07-19 0:08 ` Byungchul Park [this message]
2016-07-18 2:42 ` Byungchul Park
2016-07-08 15:07 ` Frederic Weisbecker
2016-07-18 2:37 ` Byungchul Park
2016-07-08 14:08 ` Josh Poimboeuf
2016-07-08 14:44 ` Frederic Weisbecker
2016-07-18 3:25 ` Byungchul Park
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