linux-kernel - Re: [git pull] x86 fixes

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]

Message-ID: <20080908125525.72bc1ad2@infradead.org>
Date:	Mon, 8 Sep 2008 12:55:25 -0700
From:	Arjan van de Ven <arjan@...radead.org>
To:	Linus Torvalds <torvalds@...ux-foundation.org>
Cc:	Ingo Molnar <mingo@...e.hu>, "H. Peter Anvin" <hpa@...or.com>,
	x86 maintainers <x86@...nel.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [git pull] x86 fixes

On Mon, 8 Sep 2008 12:30:02 -0700 (PDT)
Linus Torvalds <torvalds@...ux-foundation.org> wrote:
> 
> I think there are realistically three classes:
> 
>  - _really_ old, to the point of being totally useless for SMP.
> 
>    This is really just 386 and clones. We _need_ a working WP for a 
>    race-free access_ok(), and we need cmpxchg (and lately xadd).
> 
>    Smaller pains even on UP: bswap doesn't exist. invlpg doesn't
> exist. 

I'd lump all cpus that don't have cpuid in this bucket too (eg half the
486es) simply because not having cpuid is painful in pretty much the
same way.

>  - old. pre-cmov. i486 and pentium, and some clones.

makes sense
 
>  - "modern 32-bit": PPro and better. Can take CMOV, MMX and TSC for 
>    granted.

again makes sense; question is if it makes sense to take PSE and PAE
for granted as well (although PSE we can do runtime I suppose)

> Hmm? Doesn't that sound like a sane model?

it does to me; the only question is if we hit a new bucket with the
various fancy string instructions that are in upcoming models; doing
string/copy operations inlined for those guys will make a fourth bucket.


-- 
If you want to reach me at my work email, use arjan@...ux.intel.com
For development, discussion and tips for power savings, 
visit http://www.lesswatts.org
--
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/