linux-kernel - Re: [PATCH] quiet down swiotlb warnings

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: <20070601194734.GJ7217@one.firstfloor.org>
Date:	Fri, 1 Jun 2007 21:47:34 +0200
From:	Andi Kleen <andi@...stfloor.org>
To:	Rik van Riel <riel@...hat.com>
Cc:	Andi Kleen <andi@...stfloor.org>,
	Christoph Hellwig <hch@...radead.org>,
	linux-kernel <linux-kernel@...r.kernel.org>,
	andrew.vasquez@...gic.com
Subject: Re: [PATCH] quiet down swiotlb warnings

On Fri, Jun 01, 2007 at 03:38:57PM -0400, Rik van Riel wrote:
> Andi Kleen wrote:
> 
> >An pci_map_sg failing typically leads to an IO error and we've
> >always printk'ed those. Otherwise people will wonder why they
> >get EIO.
> 
> In some situations.  In this case the qla2xxx driver uses
> the pci_map_sg() failure as a throttling mechanism and

First WTF does it need swiotlb anyways? QA hardware should
be definitely DAC capable, shouldn't it?

> printing out all the warnings will actually slow down the
> system.

Another reason is that there is a lot of code that
still doesn't check the return values and when that
happens you might get data corruption too.

> 
> Andi, what do you propose as a solution?

A different interface; like I wrote in my earlier mail.

Another probabibility would be to have a blocking interface
to swiotlb that won't fail. That would be the better solution
long term, but i was told it is hard to fit into some current
driver interfaces.

-Andi
-
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/