[ovs-dev] [loss-report 3/4] dpif-linux: Slightly refactor internal data structures.
Ben Pfaff
blp at nicira.com
Fri May 25 21:36:36 UTC 2012
An initial attempt also replaced the 'uint32_t ready_mask' in struct
dpif_linux by a 'bool ready' in each struct dpif_channel, but I wasn't
happy with the result (the ready_mask bitmap works out really well) and so
I dropped that part.
Signed-off-by: Ben Pfaff <blp at nicira.com>
---
lib/dpif-linux.c | 67 +++++++++++++++++++++++++++++-------------------------
1 files changed, 36 insertions(+), 31 deletions(-)
diff --git a/lib/dpif-linux.c b/lib/dpif-linux.c
index 9d84edd..4de44a8 100644
--- a/lib/dpif-linux.c
+++ b/lib/dpif-linux.c
@@ -61,10 +61,10 @@
VLOG_DEFINE_THIS_MODULE(dpif_linux);
enum { MAX_PORTS = USHRT_MAX };
-enum { N_UPCALL_SOCKS = 17 };
-BUILD_ASSERT_DECL(IS_POW2(N_UPCALL_SOCKS - 1));
-BUILD_ASSERT_DECL(N_UPCALL_SOCKS > 1);
-BUILD_ASSERT_DECL(N_UPCALL_SOCKS <= 32); /* We use a 32-bit word as a mask. */
+enum { N_CHANNELS = 17 };
+BUILD_ASSERT_DECL(IS_POW2(N_CHANNELS - 1));
+BUILD_ASSERT_DECL(N_CHANNELS > 1);
+BUILD_ASSERT_DECL(N_CHANNELS <= 32); /* We use a 32-bit word as a mask. */
/* This ethtool flag was introduced in Linux 2.6.24, so it might be
* missing if we have old headers. */
@@ -130,15 +130,19 @@ static int dpif_linux_flow_transact(struct dpif_linux_flow *request,
static void dpif_linux_flow_get_stats(const struct dpif_linux_flow *,
struct dpif_flow_stats *);
+struct dpif_channel {
+ struct nl_sock *sock;
+};
+
/* Datapath interface for the openvswitch Linux kernel module. */
struct dpif_linux {
struct dpif dpif;
int dp_ifindex;
/* Upcall messages. */
- struct nl_sock *upcall_socks[N_UPCALL_SOCKS];
+ struct dpif_channel channels[N_CHANNELS];
uint32_t ready_mask; /* 1-bit for each sock with unread messages. */
- int epoll_fd; /* epoll fd that includes the upcall socks. */
+ int epoll_fd; /* epoll fd that includes channel socks. */
/* Change notification. */
struct sset changed_ports; /* Ports that have changed. */
@@ -256,17 +260,17 @@ open_dpif(const struct dpif_linux_dp *dp, struct dpif **dpifp)
}
static void
-destroy_upcall_socks(struct dpif_linux *dpif)
+destroy_channels(struct dpif_linux *dpif)
{
- int i;
+ struct dpif_channel *ch;
if (dpif->epoll_fd >= 0) {
close(dpif->epoll_fd);
dpif->epoll_fd = -1;
}
- for (i = 0; i < N_UPCALL_SOCKS; i++) {
- nl_sock_destroy(dpif->upcall_socks[i]);
- dpif->upcall_socks[i] = NULL;
+ for (ch = dpif->channels; ch < &dpif->channels[N_CHANNELS]; ch++) {
+ nl_sock_destroy(ch->sock);
+ ch->sock = NULL;
}
}
@@ -276,7 +280,7 @@ dpif_linux_close(struct dpif *dpif_)
struct dpif_linux *dpif = dpif_linux_cast(dpif_);
nln_notifier_destroy(dpif->port_notifier);
- destroy_upcall_socks(dpif);
+ destroy_channels(dpif);
sset_destroy(&dpif->changed_ports);
free(dpif);
}
@@ -465,9 +469,9 @@ dpif_linux_port_get_pid(const struct dpif *dpif_, uint16_t port_no)
int idx;
idx = (port_no != UINT16_MAX
- ? 1 + (port_no & (N_UPCALL_SOCKS - 2))
+ ? 1 + (port_no & (N_CHANNELS - 2))
: 0);
- return nl_sock_pid(dpif->upcall_socks[idx]);
+ return nl_sock_pid(dpif->channels[idx].sock);
}
}
@@ -989,32 +993,33 @@ dpif_linux_recv_set(struct dpif *dpif_, bool enable)
}
if (!enable) {
- destroy_upcall_socks(dpif);
+ destroy_channels(dpif);
} else {
- int i;
+ struct dpif_channel *ch;
int error;
- dpif->epoll_fd = epoll_create(N_UPCALL_SOCKS);
+ dpif->epoll_fd = epoll_create(N_CHANNELS);
if (dpif->epoll_fd < 0) {
return errno;
}
- for (i = 0; i < N_UPCALL_SOCKS; i++) {
+ for (ch = dpif->channels; ch < &dpif->channels[N_CHANNELS]; ch++) {
+ int indx = ch - dpif->channels;
struct epoll_event event;
- error = nl_sock_create(NETLINK_GENERIC, &dpif->upcall_socks[i]);
+ error = nl_sock_create(NETLINK_GENERIC, &ch->sock);
if (error) {
- destroy_upcall_socks(dpif);
+ destroy_channels(dpif);
return error;
}
memset(&event, 0, sizeof event);
event.events = EPOLLIN;
- event.data.u32 = i;
- if (epoll_ctl(dpif->epoll_fd, EPOLL_CTL_ADD,
- nl_sock_fd(dpif->upcall_socks[i]), &event) < 0) {
+ event.data.u32 = indx;
+ if (epoll_ctl(dpif->epoll_fd, EPOLL_CTL_ADD, nl_sock_fd(ch->sock),
+ &event) < 0) {
error = errno;
- destroy_upcall_socks(dpif);
+ destroy_channels(dpif);
return error;
}
}
@@ -1106,12 +1111,12 @@ dpif_linux_recv(struct dpif *dpif_, struct dpif_upcall *upcall,
}
if (!dpif->ready_mask) {
- struct epoll_event events[N_UPCALL_SOCKS];
+ struct epoll_event events[N_CHANNELS];
int retval;
int i;
do {
- retval = epoll_wait(dpif->epoll_fd, events, N_UPCALL_SOCKS, 0);
+ retval = epoll_wait(dpif->epoll_fd, events, N_CHANNELS, 0);
} while (retval < 0 && errno == EINTR);
if (retval < 0) {
static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 1);
@@ -1125,7 +1130,7 @@ dpif_linux_recv(struct dpif *dpif_, struct dpif_upcall *upcall,
while (dpif->ready_mask) {
int indx = ffs(dpif->ready_mask) - 1;
- struct nl_sock *upcall_sock = dpif->upcall_socks[indx];
+ struct dpif_channel *ch = &dpif->channels[indx];
dpif->ready_mask &= ~(1u << indx);
@@ -1137,7 +1142,7 @@ dpif_linux_recv(struct dpif *dpif_, struct dpif_upcall *upcall,
return EAGAIN;
}
- error = nl_sock_recv(upcall_sock, buf, false);
+ error = nl_sock_recv(ch->sock, buf, false);
if (error) {
if (error == ENOBUFS) {
/* ENOBUFS typically means that we've received so many
@@ -1183,14 +1188,14 @@ static void
dpif_linux_recv_purge(struct dpif *dpif_)
{
struct dpif_linux *dpif = dpif_linux_cast(dpif_);
- int i;
+ struct dpif_channel *ch;
if (dpif->epoll_fd < 0) {
return;
}
- for (i = 0; i < N_UPCALL_SOCKS; i++) {
- nl_sock_drain(dpif->upcall_socks[i]);
+ for (ch = dpif->channels; ch < &dpif->channels[N_CHANNELS]; ch++) {
+ nl_sock_drain(ch->sock);
}
}
--
1.7.2.5
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