diff options
| author | Daniel Borkmann | 2013-04-19 06:12:28 +0000 |
|---|---|---|
| committer | David S. Miller | 2013-04-25 01:29:43 -0400 |
| commit | 0578edc5604e3e192980f406f9e1040aa6434ca4 (patch) | |
| tree | 20d3f3cf7a9666235c20d541b3a3c4b938995200 | |
| parent | 660f7d22298ceb82facd2088c197f2de5cbfb7d6 (diff) | |
packet: reorder a member in packet_ring_buffer
There's a 4 byte hole in packet_ring_buffer structure before
prb_bdqc, that can be filled with 'pending' member, thus we can
reduce the overall structure size from 224 bytes to 216 bytes.
This also has the side-effect, that in struct packet_sock 2*4 byte
holes after the embedded packet_ring_buffer members are removed,
and overall, packet_sock can be reduced by 1 cacheline:
Before: size: 1344, cachelines: 21, members: 24
After: size: 1280, cachelines: 20, members: 24
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/packet/internal.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/net/packet/internal.h b/net/packet/internal.h index e891f025a1b9..650751b9a7ee 100644 --- a/net/packet/internal.h +++ b/net/packet/internal.h @@ -54,6 +54,7 @@ struct pgv { struct packet_ring_buffer { struct pgv *pg_vec; + unsigned int head; unsigned int frames_per_block; unsigned int frame_size; @@ -63,8 +64,9 @@ struct packet_ring_buffer { unsigned int pg_vec_pages; unsigned int pg_vec_len; - struct tpacket_kbdq_core prb_bdqc; atomic_t pending; + + struct tpacket_kbdq_core prb_bdqc; }; extern struct mutex fanout_mutex; |