tree 028fe1af3e85510fa7c341bfe3dadd099189156b
parent 0c03eca3d995e73d691edea8c787e25929ec156d
author Eric Dumazet <edumazet@google.com> 1344336945 +0000
committer David S. Miller <davem@davemloft.net> 1344466828 -0700

net: force dst_default_metrics to const section

While investigating on network performance problems, I found this little
gem :

$ nm -v vmlinux | grep -1 dst_default_metrics
ffffffff82736540 b busy.46605
ffffffff82736560 B dst_default_metrics
ffffffff82736598 b dst_busy_list

Apparently, declaring a const array without initializer put it in
(writeable) bss section, in middle of possibly often dirtied cache
lines.

Since we really want dst_default_metrics be const to avoid any possible
false sharing and catch any buggy writes, I force a null initializer.

ffffffff818a4c20 R dst_default_metrics

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>