diff options
| author | Eliezer Tamir <eliezer.tamir@linux.intel.com> | 2013-06-24 07:28:03 (GMT) |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-06-25 23:35:52 (GMT) |
| commit | 2d48d67fa8cd129ea85ea02d91b4a793286866f8 (patch) | |
| tree | be47e2406605760d949b08d29d988d46c4a20799 /net | |
| parent | e4f2379db6c6823c5d4a4c2c912df00c65de51d7 (diff) | |
| download | linux-2d48d67fa8cd129ea85ea02d91b4a793286866f8.tar.xz | |
net: poll/select low latency socket support
select/poll busy-poll support.
Split sysctl value into two separate ones, one for read and one for poll.
updated Documentation/sysctl/net.txt
Add a new poll flag POLL_LL. When this flag is set, sock_poll will call
sk_poll_ll if possible. sock_poll sets this flag in its return value
to indicate to select/poll when a socket that can busy poll is found.
When poll/select have nothing to report, call the low-level
sock_poll again until we are out of time or we find something.
Once the system call finds something, it stops setting POLL_LL, so it can
return the result to the user ASAP.
Signed-off-by: Eliezer Tamir <eliezer.tamir@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/sock.c | 2 | ||||
| -rw-r--r-- | net/core/sysctl_net_core.c | 8 | ||||
| -rw-r--r-- | net/socket.c | 14 |
3 files changed, 22 insertions, 2 deletions
diff --git a/net/core/sock.c b/net/core/sock.c index 1e744b1..b6c619f 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -2307,7 +2307,7 @@ void sock_init_data(struct socket *sock, struct sock *sk) #ifdef CONFIG_NET_LL_RX_POLL sk->sk_napi_id = 0; - sk->sk_ll_usec = sysctl_net_ll_poll; + sk->sk_ll_usec = sysctl_net_ll_read; #endif /* diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c index 62702c2..afc677e 100644 --- a/net/core/sysctl_net_core.c +++ b/net/core/sysctl_net_core.c @@ -306,6 +306,14 @@ static struct ctl_table net_core_table[] = { .mode = 0644, .proc_handler = proc_dointvec }, + { + .procname = "low_latency_read", + .data = &sysctl_net_ll_read, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = proc_dointvec + }, +# #endif #endif /* CONFIG_NET */ { diff --git a/net/socket.c b/net/socket.c index 3eec3f7..4da14cb 100644 --- a/net/socket.c +++ b/net/socket.c @@ -107,6 +107,7 @@ #include <net/ll_poll.h> #ifdef CONFIG_NET_LL_RX_POLL +unsigned int sysctl_net_ll_read __read_mostly; unsigned int sysctl_net_ll_poll __read_mostly; #endif @@ -1147,13 +1148,24 @@ EXPORT_SYMBOL(sock_create_lite); /* No kernel lock held - perfect */ static unsigned int sock_poll(struct file *file, poll_table *wait) { + unsigned int ll_flag = 0; struct socket *sock; /* * We can't return errors to poll, so it's either yes or no. */ sock = file->private_data; - return sock->ops->poll(file, sock, wait); + + if (sk_valid_ll(sock->sk)) { + /* this socket can poll_ll so tell the system call */ + ll_flag = POLL_LL; + + /* once, only if requested by syscall */ + if (wait && (wait->_key & POLL_LL)) + sk_poll_ll(sock->sk, 1); + } + + return ll_flag | sock->ops->poll(file, sock, wait); } static int sock_mmap(struct file *file, struct vm_area_struct *vma) |