From: David Miller <davem@davemloft.net>
To: herbert@gondor.apana.org.au
Cc: netdev@vger.kernel.org
Subject: Re: [PATCH] tcp: Set CHECKSUM_UNNECESSARY in tcp_init_nondata_skb
Date: Thu, 08 Apr 2010 11:34:20 -0700 (PDT) [thread overview]
Message-ID: <20100408.113420.268424579.davem@davemloft.net> (raw)
In-Reply-To: <20100408153906.GA26376@gondor.apana.org.au>
From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Thu, 8 Apr 2010 23:39:06 +0800
> On Thu, Apr 08, 2010 at 09:57:15PM +0800, Herbert Xu wrote:
>>
>> The problem here is that for non-data packets CHECKSUM_PARTIAL
>> can actually end up being worse if we wind up going out through
>> an interface that doesn't support checksums.
>
> I don't know what I was thinking but the above is totally wrong.
> CHECKSUM_PARTIAL should be just fine on non-checksuming interfaces
> as we'll checksum everything once just as the CHECKSUM_NONE case
> would.
>
> So with that in mind, we don't need my CHECKSUM_UNNECESSARY patch
> at all and your CHECKSUM_PARTIAL path is the right solution after
> all :)
Ok, thanks for doing all of the analysis :)
That still leaves that MC loopback code in ip_dev_loopback_xmit()
which still sets CHECKSUM_UNNECESSARY unconditionally.
Should it do like the loopback driver and just leave the ip_summed
value alone?
next prev parent reply other threads:[~2010-04-08 18:34 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-08 8:26 [PATCH] tcp: Set CHECKSUM_UNNECESSARY in tcp_init_nondata_skb David Miller
2010-04-08 9:20 ` Joe Perches
2010-04-08 11:49 ` Herbert Xu
2010-04-08 13:57 ` Herbert Xu
2010-04-08 15:39 ` Herbert Xu
2010-04-08 18:34 ` David Miller [this message]
2010-04-09 8:42 ` Herbert Xu
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20100408.113420.268424579.davem@davemloft.net \
--to=davem@davemloft.net \
--cc=herbert@gondor.apana.org.au \
--cc=netdev@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).