linux-kernel - Re: i686 quirk for AMD Geode

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 10 Nov 2009 22:27:56 +0000
From:	lsorense@...lub.uwaterloo.ca (Lennart Sorensen)
To:	"H. Peter Anvin" <hpa@...or.com>
Cc:	Willy Tarreau <w@....eu>, Pavel Machek <pavel@....cz>,
	Avi Kivity <avi@...hat.com>,
	Alan Cox <alan@...rguk.ukuu.org.uk>,
	Matteo Croce <technoboy85@...il.com>,
	Sven-Haegar Koch <haegar@...net.de>,
	Ingo Molnar <mingo@...e.hu>, linux-kernel@...r.kernel.org
Subject: Re: i686 quirk for AMD Geode

On Tue, Nov 10, 2009 at 01:19:30PM -0800, H. Peter Anvin wrote:
> Willy, perhaps you can come up with a list of features you think should
> be emulated, together with an explanation of why you opted for that list
> of features and *did not* opt for others.
> 
> Note: emulated FPU is a special subcase.  The FPU operations are
> heavyweight enough that the overhead of trapping versus library calls is
> relatively insignificant.

That doesn't seem to be the experience of the arm EABI versus the old
arm ABI with kernel FPU emulation.  Using user space library calls for
FPU is vastly faster than the trapping and kernel FPU emulation.

-- 
Len Sorensen
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/