linux-kernel - Re: [PATCH] x86/smpboot: check if CLFLUSH is actually necessary

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:	Wed, 11 Feb 2015 13:55:34 -0800
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Scotty Bauer <sbauer@....utah.edu>, tglx@...utronix.de,
	mingo@...heat.com
CC:	linux-kernel@...r.kernel.org, x86@...nel.org
Subject: Re: [PATCH] x86/smpboot: check if CLFLUSH is actually necessary

On 01/30/2015 01:26 PM, Scotty Bauer wrote:
> mwait_play_dead previously issued a CLFLUSH to work around a bug on
> some xeon processors. We can now determine if the CPU is a buggy CPU.
> This patch checks if if we're on a buggy CPU which allows non-buggy
> cpu's to eliminate the CLFLUSH.

Here is my first question: does this matter at all?  Otherwise I don't
see a point.

	-hpa


--
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/