From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Timur Tabi <timur@freescale.com>
Cc: Wood Scott-B07421 <B07421@freescale.com>,
Hu Mingkai-B21284 <B21284@freescale.com>,
"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
Xie Shaohui-B21989 <B21989@freescale.com>,
Chen Yuanquan-B41889 <B41889@freescale.com>
Subject: Re: [PATCH] powerpc/mm: add ZONE_NORMAL zone for 64 bit kernel
Date: Tue, 24 Jul 2012 13:08:38 +1000 [thread overview]
Message-ID: <1343099318.3715.0.camel@pasglop> (raw)
In-Reply-To: <500DDFF3.3000408@freescale.com>
On Mon, 2012-07-23 at 18:36 -0500, Timur Tabi wrote:
> The DMA zone only kicks in if the DMA mask is set to a size smaller
> that
> available physical memory. Sane HW should set the DMA mask to
> DMA_BIT_MASK(36). And we have plenty of sane HW on our SOCs, but not
> every device is like that.
>
> The whole point behind this patch is that some drivers are setting a
> DMA
> mask of 32, but still getting memory above 4GB.
Sure but I don't want to create the zones in the first place (and thus
introduce the added pressure on the memory management) on machines that
don't need it.
Cheers,
Ben.
next prev parent reply other threads:[~2012-07-24 3:08 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-20 12:21 [PATCH] powerpc/mm: add ZONE_NORMAL zone for 64 bit kernel Shaohui Xie
2012-07-23 6:06 ` Benjamin Herrenschmidt
2012-07-23 16:17 ` Scott Wood
2012-07-23 22:20 ` Benjamin Herrenschmidt
2012-07-23 23:08 ` Tabi Timur-B04825
2012-07-23 23:12 ` Benjamin Herrenschmidt
2012-07-23 23:15 ` Timur Tabi
2012-07-23 23:29 ` Benjamin Herrenschmidt
2012-07-23 23:30 ` Benjamin Herrenschmidt
2012-07-24 1:37 ` Scott Wood
2012-07-23 23:36 ` Timur Tabi
2012-07-24 3:08 ` Benjamin Herrenschmidt [this message]
2012-07-24 3:52 ` Tabi Timur-B04825
2012-07-24 3:59 ` Zang Roy-R61911
2012-07-24 4:04 ` Tabi Timur-B04825
2012-07-24 4:45 ` Benjamin Herrenschmidt
2012-07-24 8:01 ` Bhushan Bharat-R65777
2012-07-24 1:49 ` Scott Wood
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