* [PATCH] net: make struct net_device::min_header_len 8-bit
@ 2017-04-10 8:25 Alexey Dobriyan
2017-04-12 17:59 ` David Miller
0 siblings, 1 reply; 2+ messages in thread
From: Alexey Dobriyan @ 2017-04-10 8:25 UTC (permalink / raw)
To: davem; +Cc: netdev
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;
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH] net: make struct net_device::min_header_len 8-bit
2017-04-10 8:25 [PATCH] net: make struct net_device::min_header_len 8-bit Alexey Dobriyan
@ 2017-04-12 17:59 ` David Miller
0 siblings, 0 replies; 2+ messages in thread
From: David Miller @ 2017-04-12 17:59 UTC (permalink / raw)
To: adobriyan; +Cc: netdev
From: Alexey Dobriyan <adobriyan@gmail.com>
Date: Mon, 10 Apr 2017 11:25:26 +0300
> 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>
Applied.
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2017-04-12 17:59 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2017-04-10 8:25 [PATCH] net: make struct net_device::min_header_len 8-bit Alexey Dobriyan
2017-04-12 17:59 ` David Miller
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).