Message-ID: <1499914980.5107.18.camel@gmx.de>
Subject: Re: [PATCH v3 00/10] x86: ORC unwinder (previously undwarf)
From: Mike Galbraith <efault@gmx.de>
To: Andi Kleen <andi@firstfloor.org>, Josh Poimboeuf <jpoimboe@redhat.com>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
        live-patching@vger.kernel.org,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Andy Lutomirski <luto@kernel.org>, Jiri Slaby <jslaby@suse.cz>,
        Ingo Molnar <mingo@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>,
        Peter Zijlstra <peterz@infradead.org>
Date: Thu, 13 Jul 2017 05:03:00 +0200
In-Reply-To: <87wp7dmgoo.fsf@firstfloor.org>
References: <cover.1499786555.git.jpoimboe@redhat.com>
         <87wp7dmgoo.fsf@firstfloor.org>
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On Wed, 2017-07-12 at 15:30 -0700, Andi Kleen wrote:
> Josh Poimboeuf <jpoimboe@redhat.com> writes:
> >
> > The ORC data format does have a few downsides compared to DWARF.  The
> > ORC unwind tables take up ~1MB more memory than DWARF eh_frame tables.
> >
> Can we have an option to just use dwarf instead? For people
> who don't want to waste a MB+ to solve a problem that doesn't
> exist (as proven by many years of opensuse kernel experience)

Sure the dwarf unwinder works well for crashes, but at the price of
demolishing ftrace/perf utility.

	-Mike