kernel-ark/include/linux/sunrpc/xprtsock.h
Trond Myklebust edc1b01cd3 SUNRPC: Move TCP receive data path into a workqueue context
Stream protocols such as TCP can often build up a backlog of data to be
read due to ordering. Combine this with the fact that some workloads such
as NFS read()-intensive workloads need to receive a lot of data per RPC
call, and it turns out that receiving the data from inside a softirq
context can cause starvation.

The following patch moves the TCP data receive into a workqueue context.
We still end up calling tcp_read_sock(), but we do so from a process
context, meaning that softirqs are enabled for most of the time.

With this patch, I see a doubling of read bandwidth when running a
multi-threaded iozone workload between a virtual client and server setup.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-10-08 08:27:04 -04:00

87 lines
1.6 KiB
C

/*
* linux/include/linux/sunrpc/xprtsock.h
*
* Declarations for the RPC transport socket provider.
*/
#ifndef _LINUX_SUNRPC_XPRTSOCK_H
#define _LINUX_SUNRPC_XPRTSOCK_H
#ifdef __KERNEL__
int init_socket_xprt(void);
void cleanup_socket_xprt(void);
#define RPC_MIN_RESVPORT (1U)
#define RPC_MAX_RESVPORT (65535U)
#define RPC_DEF_MIN_RESVPORT (665U)
#define RPC_DEF_MAX_RESVPORT (1023U)
struct sock_xprt {
struct rpc_xprt xprt;
/*
* Network layer
*/
struct socket * sock;
struct sock * inet;
/*
* State of TCP reply receive
*/
__be32 tcp_fraghdr,
tcp_xid,
tcp_calldir;
u32 tcp_offset,
tcp_reclen;
unsigned long tcp_copied,
tcp_flags;
/*
* Connection of transports
*/
unsigned long sock_state;
struct delayed_work connect_worker;
struct work_struct recv_worker;
struct mutex recv_mutex;
struct sockaddr_storage srcaddr;
unsigned short srcport;
/*
* UDP socket buffer size parameters
*/
size_t rcvsize,
sndsize;
/*
* Saved socket callback addresses
*/
void (*old_data_ready)(struct sock *);
void (*old_state_change)(struct sock *);
void (*old_write_space)(struct sock *);
void (*old_error_report)(struct sock *);
};
/*
* TCP receive state flags
*/
#define TCP_RCV_LAST_FRAG (1UL << 0)
#define TCP_RCV_COPY_FRAGHDR (1UL << 1)
#define TCP_RCV_COPY_XID (1UL << 2)
#define TCP_RCV_COPY_DATA (1UL << 3)
#define TCP_RCV_READ_CALLDIR (1UL << 4)
#define TCP_RCV_COPY_CALLDIR (1UL << 5)
/*
* TCP RPC flags
*/
#define TCP_RPC_REPLY (1UL << 6)
#define XPRT_SOCK_CONNECTING 1U
#endif /* __KERNEL__ */
#endif /* _LINUX_SUNRPC_XPRTSOCK_H */