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From: Torsten Duwe <duwe@lst.de>
To: Pavel Machek <pavel@ucw.cz>
Cc: Jiri Kosina <jikos@kernel.org>, Miroslav Benes <mbenes@suse.cz>,
	Josh Poimboeuf <jpoimboe@redhat.com>,
	matz@suse.de, live-patching@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Disable non-ABI-compliant optimisations for live patching
Date: Mon, 27 Jun 2016 08:59:49 +0200	[thread overview]
Message-ID: <20160627065949.GA3399@lst.de> (raw)
In-Reply-To: <20160626223956.GD21026@amd>

On Mon, Jun 27, 2016 at 12:39:56AM +0200, Pavel Machek wrote:

> Would it be possible to document which kind of guarantees live
> patching needs from compiler?

Sure, here you go, all required guarantees:

Stick to the ABI.

> I always assumed that whoever is preparing the patch does manual
> investigation to see what needs to be changed and how, but apparantly
> that's not the case, so documentation would be good.

See above for the documentation. Imagine each architecture had a whole
hand-optimised assembler kernel. That would give some performance
improvement, right? Same issue here, only much smaller. It's ultimate
performance vs. maintainability.

HTH,
	Torsten

  reply	other threads:[~2016-06-27  7:00 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-22 14:24 [PATCH] Disable non-ABI-compliant optimisations for live patching Torsten Duwe
2016-06-22 15:19 ` Josh Poimboeuf
2016-06-23  7:45   ` Miroslav Benes
2016-06-23 10:05     ` Torsten Duwe
2016-06-23 10:45       ` Jiri Kosina
2016-06-23 12:47         ` Jiri Kosina
2016-06-26 22:39           ` Pavel Machek
2016-06-27  6:59             ` Torsten Duwe [this message]
2016-06-26 22:37 ` Pavel Machek
2016-06-27  8:13   ` Jiri Kosina
2016-06-27  8:21     ` Pavel Machek
2016-06-27  8:26       ` Jiri Kosina
2016-06-27  8:32         ` Pavel Machek
2016-06-27 11:36           ` Jiri Kosina

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