All of lore.kernel.org
 help / color / mirror / Atom feed
From: Alexey Dobriyan <adobriyan@gmail.com>
To: davem@davemloft.net
Cc: netdev@vger.kernel.org
Subject: [PATCH] net: make struct net_device::min_header_len 8-bit
Date: Mon, 10 Apr 2017 11:25:26 +0300	[thread overview]
Message-ID: <20170410082526.GC24514@avx2> (raw)

This field is never big enough to warrant 16-bitness.

8-bit accesses enjoy shorted encoding on i386/x86_64 than 16-bit
accesses:

	add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-10 (-10)
	function                                     old     new   delta
	loopback_setup                               169     164      -5
	ether_setup                                  148     143      -5

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
---

 include/linux/netdevice.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1715,7 +1715,7 @@ struct net_device {
 	unsigned int		max_mtu;
 	unsigned short		type;
 	unsigned short		hard_header_len;
-	unsigned short		min_header_len;
+	unsigned char		min_header_len;
 
 	unsigned short		needed_headroom;
 	unsigned short		needed_tailroom;

             reply	other threads:[~2017-04-10  8:25 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-10  8:25 Alexey Dobriyan [this message]
2017-04-12 17:59 ` [PATCH] net: make struct net_device::min_header_len 8-bit David Miller

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=20170410082526.GC24514@avx2 \
    --to=adobriyan@gmail.com \
    --cc=davem@davemloft.net \
    --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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.