linux-kernel - Re: [RFC v3 4/7] dmaengine: Add slave DMA interface

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]

Message-ID: <20080218142949.2c5b2810@dhcp-252-066.norway.atmel.com>
Date:	Mon, 18 Feb 2008 14:29:49 +0100
From:	Haavard Skinnemoen <hskinnemoen@...el.com>
To:	"Nelson, Shannon" <shannon.nelson@...el.com>
Cc:	"Haavard Skinnemoen" <hskinnemoen@...way.atmel.com>,
	"Williams, Dan J" <dan.j.williams@...el.com>,
	<linux-kernel@...r.kernel.org>,
	"David Brownell" <david-b@...bell.net>, <kernel@...32linux.org>,
	"Francis Moreau" <francis.moro@...il.com>,
	"Paul Mundt" <lethal@...ux-sh.org>,
	"Vladimir A. Barinov" <vbarinov@...mvista.com>,
	"Pierre Ossman" <drzeus-list@...eus.cx>
Subject: Re: [RFC v3 4/7] dmaengine: Add slave DMA interface

On Fri, 15 Feb 2008 09:12:35 -0800
"Nelson, Shannon" <shannon.nelson@...el.com> wrote:

> I'll jump in here briefly - I'm okay with the direction this is going,
> but I want to be protective of ioatdma performance.  As used in struct
> ioat_desc_sw, the cookie and ack elements end up very close to the end
> of a cache line and I'd like them to not get pushed out across the
> boundry.  I don't think this proposal changes the layout, I'm just
> bringing up my concern.

Sure, performance is very important, and it's good to see that you're
critical about the changes I'm proposing. That said, the memory layout
doesn't change at all with this patch -- the fields that didn't go into
the generic dma descriptor were at the end of the struct to begin with.

I can add a comment saying that cookie and ack must always come first.
Any other fields that we need to be careful about?

Haavard
--
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/