linux-kernel - Re: [RFC 00/15] x86_64: Optimize percpu accesses

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 for Android: free password hash cracker in your pocket

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

Date:	Wed, 9 Jul 2008 21:41:36 +0200
From:	Ingo Molnar <mingo@...e.hu>
To:	Jeremy Fitzhardinge <jeremy@...p.org>
Cc:	Christoph Lameter <cl@...ux-foundation.org>,
	Mike Travis <travis@....com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	"Eric W. Biederman" <ebiederm@...ssion.com>,
	"H. Peter Anvin" <hpa@...or.com>, Jack Steiner <steiner@....com>,
	linux-kernel@...r.kernel.org
Subject: Re: [RFC 00/15] x86_64: Optimize percpu accesses


* Jeremy Fitzhardinge <jeremy@...p.org> wrote:

>> What is remaining is the task to rename
>>
>> 	pda.Y -> Z
>>
>> in order to make variable references the same under both arches. 
>> Presumably the Z is the corresponding 32 bit variable. There are 
>> likely a number of cases where the transformation is trivial if we 
>> just identify the corresponding 32 bit equivalent.
>
> Yes, I understand that, but it's still pointless churn.  The 
> intermediate step is no improvement over what was there before, and 
> isn't any closer to the desired final result.
>
> Once you've made the pda a percpu variable, and redefined all the 
> X_pda macros in terms of x86_X_percpu, then there's no need to touch 
> all the usage sites until you're *actually* going to unify something.  
> Touching them all just because you find "X_pda" unsightly doesn't help 
> anyone.  Ideally every site you touch will remove a #ifdef 
> CONFIG_X86_64, or make two as-yet unified pieces of code closer to 
> unification.

that makes sense. Does everyone agree on #1-#2-#3 and then gradual 
elimination of most pda members (without going through an intermediate 
renaming of pda members) being the way to go?

	Ingo
--
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/