Re: [PATCH net-next v10 08/16] tls: Inline do_tcp_sendpages()

From: Tariq Toukan
Date: Tue Jun 13 2023 - 07:18:48 EST




On 07/06/2023 18:03, David Howells wrote:
Tariq Toukan <ttoukan.linux@xxxxxxxxx> wrote:

My team spotted a new degradation in TLS TX device offload, bisected to this
patch.

I presume you're using some hardware (I'm guessing Mellanox?) that can
actually do TLS offload? Unfortunately, I don't have any hardware that can do
this, so I can't test the tls_device stuff.

From a quick look at the patch, it's not clear to me what's going wrong.
Please let us know of any helpful information that we can provide to help in
the debug.

Can you find out what source line this corresponds to?

RIP: 0010:skb_splice_from_iter+0x102/0x300

Assuming you're building your own kernel, something like the following might
do the trick:

echo "RIP: 0010:skb_splice_from_iter+0x102/0x300" |
./scripts/decode_stacktrace.sh /my/built/vmlinux /my/build/tree


Hi,

It's:
RIP: 0010:skb_splice_from_iter (/usr/linux/net/core/skbuff.c:6957)

which coresponds to this line:
if (WARN_ON_ONCE(!sendpage_ok(page)))

if you run it in the kernel source tree you're using and substitute the
paths to vmlinux and the build tree for modules.

David