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| author |   Eric Dumazet <eric.dumazet@gmail.com> | 2010-11-30 19:04:07 +0000 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2010-12-09 20:05:58 -0800 |
| commit | 68835aba4d9b74e2f94106d13b6a4bddc447c4c8 (patch) | |
| tree | 468a9465acfa027791facef13fb6ef5129dda257 /Documentation | |
| parent | net: Abstract away all dst_entry metrics accesses. (diff) | |
| download | linux-dev-68835aba4d9b74e2f94106d13b6a4bddc447c4c8.tar.xz linux-dev-68835aba4d9b74e2f94106d13b6a4bddc447c4c8.zip | |
net: optimize INET input path further
Followup of commit b178bb3dfc30 (net: reorder struct sock fields)
Optimize INET input path a bit further, by :
1) moving sk_refcnt close to sk_lock.
This reduces number of dirtied cache lines by one on 64bit arches (and
64 bytes cache line size).
2) moving inet_daddr & inet_rcv_saddr at the beginning of sk
(same cache line than hash / family / bound_dev_if / nulls_node)
This reduces number of accessed cache lines in lookups by one, and dont
increase size of inet and timewait socks.
inet and tw sockets now share same place-holder for these fields.
Before patch :
offsetof(struct sock, sk_refcnt) = 0x10
offsetof(struct sock, sk_lock) = 0x40
offsetof(struct sock, sk_receive_queue) = 0x60
offsetof(struct inet_sock, inet_daddr) = 0x270
offsetof(struct inet_sock, inet_rcv_saddr) = 0x274
After patch :
offsetof(struct sock, sk_refcnt) = 0x44
offsetof(struct sock, sk_lock) = 0x48
offsetof(struct sock, sk_receive_queue) = 0x68
offsetof(struct inet_sock, inet_daddr) = 0x0
offsetof(struct inet_sock, inet_rcv_saddr) = 0x4
compute_score() (udp or tcp) now use a single cache line per ignored
item, instead of two.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'Documentation')
0 files changed, 0 insertions, 0 deletions