linux-kernel - Re: [PATCH 3/3] [UDP6]: Counter increment on BH mode

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-next>] [day] [month] [year] [list]

Date:	Mon, 3 Dec 2007 22:54:35 +1100
From:	Herbert Xu <herbert@...dor.apana.org.au>
To:	Alexey Kuznetsov <kuznet@....inr.ac.ru>
Cc:	Wang Chen <wangchen@...fujitsu.com>,
	Gerrit Renker <gerrit@....abdn.ac.uk>, davem@...emloft.net,
	andi@...stfloor.org, netdev@...r.kernel.org,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Christoph Lameter <clameter@....com>,
	Ingo Molnar <mingo@...e.hu>
Subject: Re: [PATCH 3/3] [UDP6]: Counter increment on BH mode

On Mon, Dec 03, 2007 at 02:49:12PM +0300, Alexey Kuznetsov wrote:
> On Mon, Dec 03, 2007 at 10:39:35PM +1100, Herbert Xu wrote:
> > So we need to fix this, and whatever the fix is will probably render
> > the BH/USER distinction obsolete.
> 
> Hmm, I would think opposite. USER (or generic) is expensive variant,
> BH is lite. No?

Yes that would certainly be the obvious fix.  In other words, just use
smp_processor_id instead of the raw version.  I suppose the only issue
would be that disabling/enabling preemption isn't exactly cost-free and
we're going to be doing that for every single increment.

Hmm, wasn't someone else talking about a non-atomic version of atomic
ops lately (i.e., atomic with respect to the local CPU only)? Perhaps
this is the killer app for it :)

Thanks,
-- 
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@...dor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
--
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/