From: Jakub Kicinski <kuba@kernel.org>
To: Luigi Rizzo <lrizzo@google.com>
Cc: rizzo.unipi@gmail.com, m.szyprowski@samsung.com,
robin.murphy@arm.com, willemb@google.com, kuniyu@google.com,
davem@davemloft.net, edumazet@google.com, pabeni@redhat.com,
gregkh@linuxfoundation.org, rafael@kernel.org,
akpm@linux-foundation.org, david@kernel.org,
netdev@vger.kernel.org, linux-mm@kvack.org,
iommu@lists.linux.dev, driver-core@lists.linux.dev,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] swiotlb: avoid double copy with swiotlb on tx socket
Date: Mon, 15 Jun 2026 17:25:35 -0700 [thread overview]
Message-ID: <20260615172535.080cf94f@kernel.org> (raw)
In-Reply-To: <20260615234220.3946885-1-lrizzo@google.com>
On Mon, 15 Jun 2026 23:42:20 +0000 Luigi Rizzo wrote:
> The use of swiotlb causes an extra data copy on I/O. For tx sockets,
> especially with greedy senders, this has a high chance of happening in
> the softirq handler for tx network interrupts, creating a significant
> performance bottleneck.
What's the use case? I associate swiotlb with debug / testing mostly,
so it'd be useful for people like me to explain why you care.
BTW net-next is closed: https://netdev.bots.linux.dev/net-next.html
next prev parent reply other threads:[~2026-06-16 0:25 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-15 23:42 [PATCH] swiotlb: avoid double copy with swiotlb on tx socket Luigi Rizzo
2026-06-16 0:25 ` Jakub Kicinski [this message]
2026-06-16 0:33 ` Luigi Rizzo
2026-06-16 4:17 ` Eric Dumazet
2026-06-16 5:31 ` kernel test robot
2026-06-16 8:01 ` kernel test robot
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