linux-kernel - RE: [patch] add an iterator index in struct pagevec

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] [day] [month] [year] [list]

Message-ID: <000201c71835$a3e585d0$ba88030a@amr.corp.intel.com>
Date:	Mon, 4 Dec 2006 22:21:43 -0800
From:	"Chen, Kenneth W" <kenneth.w.chen@...el.com>
To:	"'Andrew Morton'" <akpm@...l.org>
Cc:	"linux-kernel" <linux-kernel@...r.kernel.org>
Subject: RE: [patch] add an iterator index in struct pagevec

Andrew Morton wrote on Monday, December 04, 2006 9:45 PM
> On Mon, 4 Dec 2006 21:21:31 -0800
> "Chen, Kenneth W" <kenneth.w.chen@...el.com> wrote:
> 
> > pagevec is never expected to be more than PAGEVEC_SIZE, I think a
> > unsigned char is enough to count them.  This patch makes nr, cold
> > to be unsigned char
> 
> Is that on the right side of the speed/space tradeoff?

I haven't measured speed.  Size wise, making them char shrinks vmlinux
text size by 112 bytes on x86_64 (using default config option).


> I must say I'm a bit skeptical about the need for this.  But I haven't
> looked closely at the blockdev-specific dio code yet.

It was suggested to declare another struct that embeds pagevec to perform
iteration.  But I prefer to have pagevec having the capability, it is
more compact this way.

It would be nice if you can review blockdev-specific dio code.  I would
appreciate it very much.

- Ken
-
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/