From: David Howells <dhowells@redhat.com>
To: Ming Lei <ming.lei@redhat.com>
Cc: dhowells@redhat.com, Jens Axboe <axboe@kernel.dk>,
Alexander Viro <viro@zeniv.linux.org.uk>,
linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] lib/iov_iter.c: extract virt-contiguous pages in iov_iter_extract_bvec_pages
Date: Fri, 04 Oct 2024 17:56:52 +0100 [thread overview]
Message-ID: <3855842.1728061012@warthog.procyon.org.uk> (raw)
In-Reply-To: <20241004153025.1867858-1-ming.lei@redhat.com>
Ming Lei <ming.lei@redhat.com> wrote:
> All iov_iter_bvec() users only want to extract virt-contiguous pages from
> iov_iter_extract_pages() instead physical-contiguous pages.
What do you mean by "virt-contiguous"? Virtual according to what mapping?
The reason for physical contiguity is that you can pass a set of physical
contiguous pages as a single DMA descriptor. Therefore, at some point, you
might end up screwing up skb_splice_from_iter(). Currently, that's limited to
a PAGE_SIZE per fragment, but hopefully that will be fixed at some point.
David
next prev parent reply other threads:[~2024-10-04 16:57 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-04 15:30 [PATCH] lib/iov_iter.c: extract virt-contiguous pages in iov_iter_extract_bvec_pages Ming Lei
2024-10-04 16:56 ` David Howells [this message]
2024-10-06 2:55 ` Ming Lei
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