linux-kernel - Re: [PATCH] sata_sil: Greatly improve DMA support

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:	Sat, 19 May 2007 18:03:44 -0400
From:	Jeff Garzik <jeff@...zik.org>
To:	Indan Zupancic <indan@....nu>
CC:	linux-ide@...r.kernel.org, LKML <linux-kernel@...r.kernel.org>,
	Alan Cox <alan@...rguk.ukuu.org.uk>
Subject: Re: [PATCH] sata_sil: Greatly improve DMA support

Indan Zupancic wrote:
> This patch seems to work with my SiI 3512, though I don't notice any
> difference, neither a speedup, nor a slowdown. Hdparm gives the same
> speeds (-tT), and cp -a'ing kernel sources is abysmal slow in both cases,
> (need to look into that one) so I didn't really test it that well.

It won't result in much of a speedup, except in situations where IOMMU 
or other situation that causes you to run into the 64k boundary being an 
issue -- generally only on huge transfers.

A good measure is to dd(1) to/from the block device, rather than using a 
filesystem.  As has been shown on LKML, the filesystem can really slow 
things down in some cases.

	Jeff

-
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/