linux-kernel - Re: [patch] block layer: kmemcheck 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]

Date:	Thu, 07 Feb 2008 17:22:46 -0800 (PST)
From:	David Miller <davem@...emloft.net>
To:	torvalds@...ux-foundation.org
Cc:	mingo@...e.hu, jens.axboe@...cle.com, linux-kernel@...r.kernel.org,
	Alan.Brunelle@...com, arjan@...ux.intel.com, dgc@....com,
	npiggin@...e.de, akpm@...ux-foundation.org,
	vegard.nossum@...il.com, penberg@...il.com
Subject: Re: [patch] block layer: kmemcheck fixes

From: Linus Torvalds <torvalds@...ux-foundation.org>
Date: Thu, 7 Feb 2008 09:42:56 -0800 (PST)

> Can we please just stop doing these one-by-one assignments, and just do 
> something like
> 
> 	memset(rq, 0, sizeof(*rq));
> 	rq->q = q;
> 	rq->ref_count = 1;
> 	INIT_HLIST_NODE(&rq->hash);
> 	RB_CLEAR_NODE(&rq->rb_node);
> 
> instead?
> 
> The memset() is likely faster and smaller than one-by-one assignments 
> anyway, even if the one-by-ones can avoid initializing some field or there 
> ends up being a double initialization..

The problem is store buffer compression.  At least a few years
ago this made a huge difference in sk_buff initialization in the
networking.

Maybe cpus these days have so much store bandwith that doing
things like the above is OK, but I doubt it :-)
--
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/