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Message-ID: <ecbb5d7e-7238-28e2-1a17-686325e2bb50@gmail.com>
Date:   Mon, 19 Jun 2023 11:23:22 +0300
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Subject: Re: [PATCH net-next v10 08/16] tls: Inline do_tcp_sendpages()
To:     David Howells <dhowells@redhat.com>
Cc:     netdev@vger.kernel.org, "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Willem de Bruijn <willemdebruijn.kernel@gmail.com>,
        David Ahern <dsahern@kernel.org>,
        Matthew Wilcox <willy@infradead.org>,
        Al Viro <viro@zeniv.linux.org.uk>,
        Christoph Hellwig <hch@infradead.org>,
        Jens Axboe <axboe@kernel.dk>, Jeff Layton <jlayton@kernel.org>,
        Christian Brauner <brauner@kernel.org>,
        Chuck Lever III <chuck.lever@oracle.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org, Boris Pismenny <borisp@nvidia.com>,
        John Fastabend <john.fastabend@gmail.com>,
        Gal Pressman <gal@nvidia.com>, ranro@nvidia.com,
        samiram@nvidia.com, drort@nvidia.com,
        Tariq Toukan <tariqt@nvidia.com>
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 <2267272.1686150217@warthog.procyon.org.uk>
 <5a9d4ffb-a569-3f60-6ac8-070ab5e5f5ad@gmail.com>
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From:   Tariq Toukan <ttoukan.linux@gmail.com>
In-Reply-To: <5a9d4ffb-a569-3f60-6ac8-070ab5e5f5ad@gmail.com>
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On 13/06/2023 14:15, Tariq Toukan wrote:
> 
> 
> On 07/06/2023 18:03, David Howells wrote:
>> Tariq Toukan <ttoukan.linux@gmail.com> 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)))
> 

Hi David,
Any other debug information that we can provide to progress with the 
analysis?