diff options
| author | Eric Dumazet <edumazet@google.com> | 2016-04-01 08:52:12 -0700 |
|---|---|---|
| committer | Subash Abhinov Kasiviswanathan <subashab@codeaurora.org> | 2016-11-28 14:42:09 -0700 |
| commit | 68610ce9d9f2b7c1d455b529090ca0dab83a3153 (patch) | |
| tree | 3dfcdb45a872dd7501fbd7e1bc9d0d63e8fa506d /include/net | |
| parent | 9aa1df0cf5ffb58b52b55b4fe2ea6531f795e186 (diff) | |
net: add SOCK_RCU_FREE socket flag
We want a generic way to insert an RCU grace period before socket
freeing for cases where RCU_SLAB_DESTROY_BY_RCU is adding too
much overhead.
SLAB_DESTROY_BY_RCU strict rules force us to take a reference
on the socket sk_refcnt, and it is a performance problem for UDP
encapsulation, or TCP synflood behavior, as many CPUs might
attempt the atomic operations on a shared sk_refcnt
UDP sockets and TCP listeners can set SOCK_RCU_FREE so that their
lookup can use traditional RCU rules, without refcount changes.
They can set the flag only once hashed and visible by other cpus.
CRs-Fixed: 1094434
Change-Id: Ib4967b801cc5b48c8ac4793b7a03fbfafba2234a
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tom Herbert <tom@herbertland.com>
Tested-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Git-commit: a4298e4522d687a79af8f8fbb7eca68399ab2d81
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
[subashab@codeaurora.org: resolve trivial merge conflicts]
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Diffstat (limited to 'include/net')
| -rw-r--r-- | include/net/sock.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/net/sock.h b/include/net/sock.h index fca6e414f844..0e49452f5c48 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -457,6 +457,7 @@ struct sock { int (*sk_backlog_rcv)(struct sock *sk, struct sk_buff *skb); void (*sk_destruct)(struct sock *sk); + struct rcu_head sk_rcu; }; #define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data))) @@ -739,6 +740,7 @@ enum sock_flags { */ SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */ SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */ + SOCK_RCU_FREE, /* wait rcu grace period in sk_destruct() */ }; #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE)) |