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Date: Thu, 30 Jan 2025 16:48:36 -0800
From: Andrew Morton <akpm@linux-foundation.org>
To: "Vishal Moola (Oracle)" <vishal.moola@gmail.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, hch@infradead.org,
 urezki@gmail.com, intel-gfx@lists.freedesktop.org
Subject: Re: [PATCH 0/2] vmalloc: Introduce vmap_file()
Message-Id: <20250130164836.1163f66bede77ec4bcc9d4b9@linux-foundation.org>
In-Reply-To: <20250131001806.92349-1-vishal.moola@gmail.com>
References: <20250131001806.92349-1-vishal.moola@gmail.com>
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On Thu, 30 Jan 2025 16:18:04 -0800 "Vishal Moola (Oracle)" <vishal.moola@gmail.com> wrote:

> Currently, users have to call vmap() or vmap_pfn() to map pages to
> kernel virtual space. vmap() requires the page references, and
> vmap_pfn() requires page pfns. If we have a file but no page references,
> we have to do extra work to map them.
> 
> Create a function, vmap_file(), to map a specified range of a given
> file to kernel virtual space. Also convert a user that benefits from
> vmap_file().
> 

Seems like a pretty specialized thing.  Have you identified any other
potential users of vmap_file()?  I couldn't see any.

If drm is likely to remain the only user of this, perhaps we should
leave the code down in drivers/gpu/drm for now?


Also, the amount of copy-n-pasting from vmap() into vmap_file() is
undesirable - code size, maintenance overhead, etc.