From: Peter Zijlstra <peterz@infradead.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>,
x86@kernel.org, linux-kernel@vger.kernel.org, luto@kernel.org
Subject: Re: [RFC][PATCH 3/3] x86/entry, ORC: Teach objtool/unwind_orc about stack irq swizzles
Date: Fri, 8 May 2020 12:12:09 +0200 [thread overview]
Message-ID: <20200508101209.GY5298@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <878si3e8v2.fsf@nanos.tec.linutronix.de>
On Thu, May 07, 2020 at 11:24:49PM +0200, Thomas Gleixner wrote:
> But over our IRC conversation I came up with a 3rd variant:
>
> For most of the vectors the indirect call overhead is just noise, so
> we can run them through the ASM switcher, but for the resched IPI
> we can just use a separate direct call stub in ASM.
Are we sure the rat-poison crap is noise for all the other system
vectors? I suppose it is for most since they'll do indirect calls
themselves anyway, right?
> I can live with that. I might have to pay up for Peter's headaches to
> teach objtool, but that's a different story. Let me check how many beers
> he owes me first ...
We're going to be so massively drunk if we ever settle that :-) For now
I'll just have to live with knowing more about the unwinders.
next prev parent reply other threads:[~2020-05-08 10:12 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-07 16:10 [RFC][PATCH 0/3] objtool vs irqstack swizzles Peter Zijlstra
2020-05-07 16:10 ` [RFC][PATCH 1/3] x86/entry: Collapse the 3 IRQ stack instances into a single macro Peter Zijlstra
2020-05-07 16:10 ` [RFC][PATCH 2/3] x86/entry: Provide ASM_INSTR_{BEGIN,END} Peter Zijlstra
2020-05-07 16:10 ` [RFC][PATCH 3/3] x86/entry, ORC: Teach objtool/unwind_orc about stack irq swizzles Peter Zijlstra
2020-05-07 17:38 ` Peter Zijlstra
2020-05-07 18:30 ` Josh Poimboeuf
2020-05-07 21:24 ` Thomas Gleixner
2020-05-08 10:12 ` Peter Zijlstra [this message]
2020-05-08 12:26 ` Thomas Gleixner
2020-05-08 12:40 ` Peter Zijlstra
2020-05-08 12:44 ` Thomas Gleixner
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