path: root/fs/ocfs2/cluster/tcp_internal.h
diff options
authorZhen Wei <zwei@novell.com>2007-01-23 17:19:59 -0800
committerMark Fasheh <mark.fasheh@oracle.com>2007-02-07 12:15:11 -0800
commit925037bcba7691db2403684141a276930ad184f3 (patch)
tree5a928f3d3f8488d1094a4ced8f39228c9d5a8ca9 /fs/ocfs2/cluster/tcp_internal.h
parent[PATCH] ocfs2: drop INET from Kconfig, not needed (diff)
ocfs2: introduce sc->sc_send_lock to protect outbound outbound messages
When there is a lot of multithreaded I/O usage, two threads can collide while sending out a message to the other nodes. This is due to the lack of locking between threads while sending out the messages. When a connected TCP send(), sendto(), or sendmsg() arrives in the Linux kernel, it eventually comes through tcp_sendmsg(). tcp_sendmsg() protects itself by acquiring a lock at invocation by calling lock_sock(). tcp_sendmsg() then loops over the buffers in the iovec, allocating associated sk_buff's and cache pages for use in the actual send. As it does so, it pushes the data out to tcp for actual transmission. However, if one of those allocation fails (because a large number of large sends is being processed, for example), it must wait for memory to become available. It does so by jumping to wait_for_sndbuf or wait_for_memory, both of which eventually cause a call to sk_stream_wait_memory(). sk_stream_wait_memory() contains a code path that calls sk_wait_event(). Finally, sk_wait_event() contains the call to release_sock(). The following patch adds a lock to the socket container in order to properly serialize outbound requests. From: Zhen Wei <zwei@novell.com> Acked-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Diffstat (limited to '')
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/ocfs2/cluster/tcp_internal.h b/fs/ocfs2/cluster/tcp_internal.h
index 177927a8f007..4dae5df5e467 100644
--- a/fs/ocfs2/cluster/tcp_internal.h
+++ b/fs/ocfs2/cluster/tcp_internal.h
@@ -155,6 +155,8 @@ struct o2net_sock_container {
struct timeval sc_tv_func_stop;
u32 sc_msg_key;
u16 sc_msg_type;
+ struct mutex sc_send_lock;
struct o2net_msg_handler {