linux-kernel - Re: [PATCH 3/7] slub: Do not use c->page on free

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:	Tue, 16 Dec 2014 16:15:21 +0100
From:	Jesper Dangaard Brouer <brouer@...hat.com>
To:	Christoph Lameter <cl@...ux.com>
Cc:	Joonsoo Kim <iamjoonsoo.kim@....com>,
	Andrey Ryabinin <ryabinin.a.a@...il.com>,
	akpm@...uxfoundation.org, rostedt@...dmis.org,
	LKML <linux-kernel@...r.kernel.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	"linux-mm@...ck.org" <linux-mm@...ck.org>,
	Pekka Enberg <penberg@...nel.org>, brouer@...hat.com
Subject: Re: [PATCH 3/7] slub: Do not use c->page on free

On Tue, 16 Dec 2014 08:53:08 -0600 (CST)
Christoph Lameter <cl@...ux.com> wrote:

> On Tue, 16 Dec 2014, Joonsoo Kim wrote:
> 
> > > Like this:
> > >
> > >         return d > 0 && d < page->objects * s->size;
> > >
> >
> > Yes! That's what I'm looking for.
> > Christoph, how about above change?
> 
> Ok but now there is a multiplication in the fast path.

Could we pre-calculate the value (page->objects * s->size) and e.g store it
in struct kmem_cache, thus saving the imul ?

-- 
Best regards,
  Jesper Dangaard Brouer
  MSc.CS, Sr. Network Kernel Developer at Red Hat
  Author of http://www.iptv-analyzer.org
  LinkedIn: http://www.linkedin.com/in/brouer
--
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/