linux-kernel - Re: [PATCH] pci: print out DMA mask info

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: <20081012073859.GE20056@colo.lackof.org>
Date:	Sun, 12 Oct 2008 01:38:59 -0600
From:	Grant Grundler <grundler@...isc-linux.org>
To:	Roland Dreier <rdreier@...co.com>
Cc:	Matthew Wilcox <matthew@....cx>, Yinghai Lu <yinghai@...nel.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Jesse Barnes <jbarnes@...tuousgeek.org>,
	FUJITA Tomonori <fujita.tomonori@....ntt.co.jp>,
	grundler@...isc-linux.org, mingo@...e.hu, tglx@...utronix.de,
	hpa@...or.com, linux-kernel@...r.kernel.org,
	linux-pci@...r.kernel.org
Subject: Re: [PATCH] pci: print out DMA mask info

On Fri, Oct 10, 2008 at 10:18:33AM -0700, Roland Dreier wrote:
>  > Open-coding DMA_BIT_MASK() within your driver means that we no longer
>  > have a canonical list of DMA masks in one place.  Instead we have to
>  > grep the entire tree and come up with more-or-less complex scripts to
>  > figure out which bit masks are actually in use.
> 
> Out of curiousity, why do we care about that list?

Originally, I used to track down IO perf issues when porting drivers to ia64.

But knowing the dma masks in use on specific platforms might allow
folks to disable DMA_ZONE (like ia64 since it's always guarateed
either a SWIOTLB or real IOMMU).

Any other uses?

thanks,
grant

> 
>  - R.
> --
> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
> the body of a message to majordomo@...r.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
--
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/