linux-kernel - Re: [PATCH] x86: adjust GFP mask handling for coherent allocations

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, 27 Oct 2009 09:00:51 +0000
From:	"Jan Beulich" <JBeulich@...ell.com>
To:	"Ingo Molnar" <mingo@...e.hu>
Cc:	"Yinghai Lu" <yinghai@...nel.org>, <tglx@...utronix.de>,
	"Takashi Iwai" <tiwai@...e.de>, <linux-kernel@...r.kernel.org>,
	<jbarnes@...tuousgeek.org>, <hpa@...or.com>
Subject: Re: [PATCH] x86: adjust GFP mask handling for coherent
	 allocations

>>> Ingo Molnar <mingo@...e.hu> 26.10.09 21:19 >>>
>
>* Jan Beulich <JBeulich@...ell.com> wrote:
>
>> >>> Ingo Molnar <mingo@...e.hu> 26.10.09 16:22 >>>
>> >* Jan Beulich <JBeulich@...ell.com> wrote:
>> >> And any attempt to eliminate the conditional another way would just 
>> >> introduce a very similar conditional elsewhere; with this having a 
>> >> single user (and foreseeably not ever a second one) I would think this 
>> >> would just make the code less readable.
>> >
>> >There's 3 other current uses of DMA_BIT_MASK(24) in arch/x86 - couldnt 
>> >those use ISA_DMA_BIT_MASK too?
>> 
>> Oh, so you didn't mean me to eliminate the conditional in pci-dma.c, 
>> but just to replace the DMA_BIT_MASK(24) here an elsewhere. Sure, I'm 
>> fine with adding this to the patch.
>
>Well, can ISA_BIT_MASK fall back to DMA_BIT_MASK(32) on !CONFIG_ISA? If 
>we have ISA support disabled we might as well pretend the whole world is 
>PCI, right?
>
>That way we'd get rid of that #ifdef in the .c code too.

I can certainly code it that way, but then we can't use it to replace any
instance of DMA_BIT_MASK(24) used to derive the need for GFP_DMA.
So I'm not sure elimination of which of the instances of DMA_BIT_MASK(24)
is more desirable...

Jan

--
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/