From: Christoph Hellwig <hch@lst.de>
To: Gao Xiang <hsiangkao@linux.alibaba.com>
Cc: Christoph Hellwig <hch@lst.de>,
akpm@linux-foundation.org, bingbu.cao@linux.intel.com,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
lorenzo.stoakes@oracle.com, opensource.kernel@vivo.com,
rppt@kernel.org, ryan.roberts@arm.com, urezki@gmail.com,
ziy@nvidia.com, vivek.kasireddy@intel.com,
Huan Yang <link@vivo.com>
Subject: Re: [PATCH] mm/vmalloc: fix mischeck pfn valid in vmap_pfns
Date: Thu, 20 Mar 2025 06:31:47 +0100 [thread overview]
Message-ID: <20250320053147.GB12560@lst.de> (raw)
In-Reply-To: <64a43d16-606c-4255-8a8b-96d6e4e44729@linux.alibaba.com>
On Wed, Mar 19, 2025 at 05:09:06PM +0800, Gao Xiang wrote:
> The minimum map unit is page size instead of variable-size folio.
>
> For many cases, vmap (to combine many partial folios) is useful
> (instead of split all folios to order-0 folios in advance) but
> I agree page array may be inefficient.
>
> So I don't think another folio vmap() version is better overall
> anyway.
Then just reject the mappings for now. vmap/vm_map_ram isn't really
intended for mapping totally arbitrary scattered memory anyway.
As mentioned before udmabuf also has a grave bug in the dma mapping
part, so just marking it broken would be another very sensible
option.
next prev parent reply other threads:[~2025-03-20 5:31 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-12 6:15 Huan Yang
2025-03-12 6:18 ` Christoph Hellwig
2025-03-17 2:12 ` Huan Yang
2025-03-17 5:29 ` Bingbu Cao
2025-03-17 5:53 ` Christoph Hellwig
2025-03-17 7:42 ` Huan Yang
2025-03-18 6:48 ` Christoph Hellwig
2025-03-18 8:20 ` Huan Yang
2025-03-18 8:33 ` Christoph Hellwig
2025-03-18 8:39 ` Huan Yang
2025-03-18 8:44 ` Christoph Hellwig
2025-03-18 8:50 ` Huan Yang
[not found] ` <20250319050359.3484-1-hdanton@sina.com>
2025-03-19 8:08 ` Christoph Hellwig
[not found] ` <20250319112651.3502-1-hdanton@sina.com>
2025-03-24 2:13 ` Huan Yang
2025-03-25 6:32 ` Kasireddy, Vivek
2025-03-25 6:46 ` Bingbu Cao
2025-03-27 13:40 ` Matthew Wilcox
2025-03-28 6:13 ` Huan Yang
2025-03-19 9:09 ` Gao Xiang
2025-03-20 5:31 ` Christoph Hellwig [this message]
2025-03-24 2:22 ` Huan Yang
2025-03-24 2:57 ` Matthew Wilcox
2025-03-17 6:26 ` Huan Yang
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