From: Christoph Hellwig <hch@infradead.org>
To: Nicolas Boichat <drinkcat@chromium.org>
Cc: Will Deacon <will.deacon@arm.com>,
Robin Murphy <robin.murphy@arm.com>,
Joerg Roedel <joro@8bytes.org>, Christoph Lameter <cl@linux.com>,
Pekka Enberg <penberg@kernel.org>,
David Rientjes <rientjes@google.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Andrew Morton <akpm@linux-foundation.org>,
Vlastimil Babka <vbabka@suse.cz>, Michal Hocko <mhocko@suse.com>,
Mel Gorman <mgorman@techsingularity.net>,
Levin Alexander <Alexander.Levin@microsoft.com>,
Huaisheng Ye <yehs1@lenovo.com>,
Mike Rapoport <rppt@linux.vnet.ibm.com>,
linux-arm-kernel@lists.infradead.org,
iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, Yong Wu <yong.wu@mediatek.com>,
Matthias Brugger <matthias.bgg@gmail.com>,
Tomasz Figa <tfiga@google.com>,
yingjoe.chen@mediatek.com, hch@infradead.org,
Matthew Wilcox <willy@infradead.org>
Subject: Re: [PATCH v4 3/3] iommu/io-pgtable-arm-v7s: Request DMA32 memory, and improve debugging
Date: Wed, 5 Dec 2018 05:54:06 -0800 [thread overview]
Message-ID: <20181205135406.GA29031@infradead.org> (raw)
In-Reply-To: <20181205054828.183476-4-drinkcat@chromium.org>
On Wed, Dec 05, 2018 at 01:48:28PM +0800, Nicolas Boichat wrote:
> IOMMUs using ARMv7 short-descriptor format require page tables
> (level 1 and 2) to be allocated within the first 4GB of RAM, even
> on 64-bit systems.
> +#ifdef CONFIG_ZONE_DMA32
> +#define ARM_V7S_TABLE_GFP_DMA GFP_DMA32
> +#define ARM_V7S_TABLE_SLAB_CACHE SLAB_CACHE_DMA32
> +#else
> +#define ARM_V7S_TABLE_GFP_DMA GFP_DMA
> +#define ARM_V7S_TABLE_SLAB_CACHE SLAB_CACHE_DMA
> +#endif
How does using GFP_DMA make sense based on the above? If the system
has more than 32-bits worth of RAM it should be using GFP_DMA32, else
GFP_KERNEL, not GFP_DMA for an arch defined small addressability pool.
next prev parent reply other threads:[~2018-12-05 13:54 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-05 5:48 [PATCH v4 0/3] iommu/io-pgtable-arm-v7s: Use DMA32 zone for page tables Nicolas Boichat
2018-12-05 5:48 ` [PATCH v4 1/3] mm: slab/slub: Add check_slab_flags function to check for valid flags Nicolas Boichat
2018-12-05 13:34 ` Vlastimil Babka
2018-12-05 5:48 ` [PATCH v4 2/3] mm: Add support for kmem caches in DMA32 zone Nicolas Boichat
2018-12-05 7:25 ` Wei Yang
2018-12-05 7:39 ` Nicolas Boichat
2018-12-05 9:18 ` Wei Yang
2018-12-05 12:18 ` Wei Yang
2018-12-06 0:41 ` Nicolas Boichat
2018-12-06 3:32 ` Wei Yang
2018-12-06 3:55 ` Nicolas Boichat
2018-12-06 6:29 ` Wei Yang
2018-12-05 9:55 ` Michal Hocko
2018-12-05 11:01 ` Nicolas Boichat
2018-12-05 11:37 ` Michal Hocko
2018-12-05 13:59 ` Vlastimil Babka
2018-12-06 3:49 ` Nicolas Boichat
2018-12-06 9:34 ` Vlastimil Babka
2018-12-06 10:09 ` Nicolas Boichat
2018-12-05 5:48 ` [PATCH v4 3/3] iommu/io-pgtable-arm-v7s: Request DMA32 memory, and improve debugging Nicolas Boichat
2018-12-05 13:54 ` Christoph Hellwig [this message]
2018-12-05 14:40 ` Robin Murphy
2018-12-05 14:43 ` Christoph Hellwig
2018-12-05 14:46 ` Will Deacon
2018-12-05 14:43 ` Vlastimil Babka
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20181205135406.GA29031@infradead.org \
--to=hch@infradead.org \
--cc=Alexander.Levin@microsoft.com \
--cc=akpm@linux-foundation.org \
--cc=cl@linux.com \
--cc=drinkcat@chromium.org \
--cc=iamjoonsoo.kim@lge.com \
--cc=iommu@lists.linux-foundation.org \
--cc=joro@8bytes.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=matthias.bgg@gmail.com \
--cc=mgorman@techsingularity.net \
--cc=mhocko@suse.com \
--cc=penberg@kernel.org \
--cc=rientjes@google.com \
--cc=robin.murphy@arm.com \
--cc=rppt@linux.vnet.ibm.com \
--cc=tfiga@google.com \
--cc=vbabka@suse.cz \
--cc=will.deacon@arm.com \
--cc=willy@infradead.org \
--cc=yehs1@lenovo.com \
--cc=yingjoe.chen@mediatek.com \
--cc=yong.wu@mediatek.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).