VLOG_DEFINE_THIS_MODULE(dpif_linux);
enum { MAX_PORTS = USHRT_MAX };
-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. */
#define ETH_FLAG_LRO (1 << 15) /* LRO is enabled */
static void dpif_linux_flow_get_stats(const struct dpif_linux_flow *,
struct dpif_flow_stats *);
-/* Packet drop monitoring.
- *
- * When kernel-to-user Netlink buffers overflow, the kernel notifies us that
- * one or more packets were dropped, but it doesn't tell us anything about
- * those packets. However, the administrator really wants to know. So we do
- * the next best thing, and keep track of the top sources of packets received
- * on each kernel-to-user channel, since the top sources are those that will
- * cause the buffers to overflow.
- *
- * We use a variation on the "Space-Saving" algorithm in Metwally et al.,
- * "Efficient Computation of Frequent and Top-k Elements in Data Streams", ACM
- * Transactions on Database Systems 31:3 (2006). This algorithm yields
- * perfectly accurate results when the data stream's unique values (in this
- * case, port numbers) fit into our data structure, and degrades gracefully
- * even for challenging distributions (e.g. Zipf).
- *
- * Our implementation is very simple, without any of the special flourishes
- * described in the paper. It avoids the need to use a hash for lookup by
- * keeping the constant factor (N_SKETCHES) very small. The error calculations
- * in the paper make it sound like the results should still be satisfactory.
- *
- * "space-saving" and "Metwally" seem like awkward names for data structures,
- * so we call this a "sketch" even though technically that's a different sort
- * of summary structure.
- */
-
-/* One of N_SKETCHES counting elements per channel in the Metwally
- * "space-saving" algorithm. */
-enum { N_SKETCHES = 8 }; /* Number of elements per channel. */
-struct dpif_sketch {
- uint32_t port_no; /* Port number. */
- unsigned int hits; /* Number of hits. */
- unsigned int error; /* Upper bound on error in 'hits'. */
-};
-
-/* One of N_CHANNELS channels per dpif between the kernel and userspace. */
+/* One of the dpif channels between the kernel and userspace. */
struct dpif_channel {
struct nl_sock *sock; /* Netlink socket. */
- struct dpif_sketch sketches[N_SKETCHES]; /* From max to min 'hits'. */
long long int last_poll; /* Last time this channel was polled. */
};
-static void update_sketch(struct dpif_channel *, uint32_t port_no);
-static void scale_sketches(struct dpif *);
static void report_loss(struct dpif *, struct dpif_channel *);
-/* Interval, in milliseconds, at which to scale down the sketch values by a
- * factor of 2. The Metwally algorithm doesn't do this, which makes sense in
- * the context it assumes, but in our situation we ought to weight recent data
- * more heavily than old data, so in my opinion this is reasonable. */
-#define SCALE_INTERVAL (60 * 1000)
-
/* Datapath interface for the openvswitch Linux kernel module. */
struct dpif_linux {
struct dpif dpif;
int dp_ifindex;
/* Upcall messages. */
- struct dpif_channel channels[N_CHANNELS];
- uint32_t ready_mask; /* 1-bit for each sock with unread messages. */
+ int uc_array_size; /* Size of 'channels' and 'epoll_events'. */
+ struct dpif_channel *channels;
+ struct epoll_event *epoll_events;
int epoll_fd; /* epoll fd that includes channel socks. */
- long long int next_scale; /* Next time to scale down the sketches. */
+ int n_events; /* Num events returned by epoll_wait(). */
+ int event_offset; /* Offset into 'epoll_events'. */
/* Change notification. */
struct sset changed_ports; /* Ports that have changed. */
dpif_init(&dpif->dpif, &dpif_linux_class, dp->name,
dp->dp_ifindex, dp->dp_ifindex);
- dpif->next_scale = LLONG_MAX;
-
dpif->dp_ifindex = dp->dp_ifindex;
sset_init(&dpif->changed_ports);
*dpifp = &dpif->dpif;
static void
destroy_channels(struct dpif_linux *dpif)
{
- struct dpif_channel *ch;
+ int i;
- if (dpif->epoll_fd >= 0) {
- close(dpif->epoll_fd);
- dpif->epoll_fd = -1;
+ if (dpif->epoll_fd < 0) {
+ return;
}
- for (ch = dpif->channels; ch < &dpif->channels[N_CHANNELS]; ch++) {
+
+ for (i = 0; i < dpif->uc_array_size; i++ ) {
+ struct dpif_linux_vport vport_request;
+ struct dpif_channel *ch = &dpif->channels[i];
+ uint32_t upcall_pid = 0;
+
+ if (!ch->sock) {
+ continue;
+ }
+
+ /* Turn off upcalls. */
+ dpif_linux_vport_init(&vport_request);
+ vport_request.cmd = OVS_VPORT_CMD_SET;
+ vport_request.dp_ifindex = dpif->dp_ifindex;
+ vport_request.port_no = i;
+ vport_request.upcall_pid = &upcall_pid;
+ dpif_linux_vport_transact(&vport_request, NULL, NULL);
+
nl_sock_destroy(ch->sock);
- ch->sock = NULL;
}
- dpif->next_scale = LLONG_MAX;
+
+ free(dpif->channels);
+ dpif->channels = NULL;
+ dpif->uc_array_size = 0;
+
+ free(dpif->epoll_events);
+ dpif->epoll_events = NULL;
+ dpif->n_events = dpif->event_offset = 0;
+
+ close(dpif->epoll_fd);
+ dpif->epoll_fd = -1;
+}
+
+static int
+add_channel(struct dpif_linux *dpif, uint32_t port_no, struct nl_sock *sock)
+{
+ struct epoll_event event;
+
+ if (dpif->epoll_fd < 0) {
+ return 0;
+ }
+
+ /* We assume that the datapath densely chooses port numbers, which
+ * can therefore be used as an index into an array of channels. */
+ if (port_no >= dpif->uc_array_size) {
+ int new_size = port_no + 1;
+ int i;
+
+ if (new_size > 65535) {
+ VLOG_WARN_RL(&error_rl, "%s: datapath port %"PRIu32" too big",
+ dpif_name(&dpif->dpif), port_no);
+ return EFBIG;
+ }
+
+ dpif->channels = xrealloc(dpif->channels,
+ new_size * sizeof *dpif->channels);
+ for (i = dpif->uc_array_size; i < new_size; i++) {
+ dpif->channels[i].sock = NULL;
+ }
+
+ dpif->epoll_events = xrealloc(dpif->epoll_events,
+ new_size * sizeof *dpif->epoll_events);
+ dpif->uc_array_size = new_size;
+ }
+
+ memset(&event, 0, sizeof event);
+ event.events = EPOLLIN;
+ event.data.u32 = port_no;
+ if (epoll_ctl(dpif->epoll_fd, EPOLL_CTL_ADD, nl_sock_fd(sock),
+ &event) < 0) {
+ return errno;
+ }
+
+ dpif->channels[port_no].sock = sock;
+ dpif->channels[port_no].last_poll = LLONG_MIN;
+
+ return 0;
+}
+
+static void
+del_channel(struct dpif_linux *dpif, uint32_t port_no)
+{
+ struct dpif_channel *ch;
+
+ if (dpif->epoll_fd < 0 || port_no >= dpif->uc_array_size) {
+ return;
+ }
+
+ ch = &dpif->channels[port_no];
+ if (!ch->sock) {
+ return;
+ }
+
+ epoll_ctl(dpif->epoll_fd, EPOLL_CTL_DEL, nl_sock_fd(ch->sock), NULL);
+
+ nl_sock_destroy(ch->sock);
+ ch->sock = NULL;
}
static void
}
static void
-dpif_linux_run(struct dpif *dpif_)
+dpif_linux_run(struct dpif *dpif_ OVS_UNUSED)
{
- struct dpif_linux *dpif = dpif_linux_cast(dpif_);
-
- if (time_msec() >= dpif->next_scale) {
- dpif->next_scale = time_msec() + SCALE_INTERVAL;
- scale_sketches(dpif_);
- }
-
if (nln) {
nln_run(nln);
}
const char *type = netdev_get_type(netdev);
struct dpif_linux_vport request, reply;
const struct ofpbuf *options;
+ struct nl_sock *sock = NULL;
uint32_t upcall_pid;
struct ofpbuf *buf;
int error;
+ if (dpif->epoll_fd >= 0) {
+ error = nl_sock_create(NETLINK_GENERIC, &sock);
+ if (error) {
+ return error;
+ }
+ }
+
dpif_linux_vport_init(&request);
request.cmd = OVS_VPORT_CMD_NEW;
request.dp_ifindex = dpif->dp_ifindex;
VLOG_WARN_RL(&error_rl, "%s: cannot create port `%s' because it has "
"unsupported type `%s'",
dpif_name(dpif_), name, type);
+ nl_sock_destroy(sock);
return EINVAL;
}
request.name = name;
}
request.port_no = *port_nop;
- upcall_pid = dpif_linux_port_get_pid(dpif_, request.port_no);
+ upcall_pid = sock ? nl_sock_pid(sock) : 0;
request.upcall_pid = &upcall_pid;
error = dpif_linux_vport_transact(&request, &reply, &buf);
-
if (!error) {
*port_nop = reply.port_no;
VLOG_DBG("%s: assigning port %"PRIu32" to netlink pid %"PRIu32,
dpif_name(dpif_), reply.port_no, upcall_pid);
} else if (error == EBUSY && *port_nop != UINT32_MAX) {
VLOG_INFO("%s: requested port %"PRIu32" is in use",
- dpif_name(dpif_), *port_nop);
+ dpif_name(dpif_), *port_nop);
+ nl_sock_destroy(sock);
+ ofpbuf_delete(buf);
+ return error;
}
-
ofpbuf_delete(buf);
- return error;
+ if (sock) {
+ error = add_channel(dpif, *port_nop, sock);
+ if (error) {
+ VLOG_INFO("%s: could not add channel for port %s",
+ dpif_name(dpif_), name);
+
+ /* Delete the port. */
+ dpif_linux_vport_init(&request);
+ request.cmd = OVS_VPORT_CMD_DEL;
+ request.dp_ifindex = dpif->dp_ifindex;
+ request.port_no = *port_nop;
+ dpif_linux_vport_transact(&request, NULL, NULL);
+
+ nl_sock_destroy(sock);
+ return error;
+ }
+ }
+
+ return 0;
}
static int
vport.port_no = port_no;
error = dpif_linux_vport_transact(&vport, NULL, NULL);
+ del_channel(dpif, port_no);
+
return error;
}
if (dpif->epoll_fd < 0) {
return 0;
} else {
- int idx;
-
- idx = (port_no != UINT32_MAX
- ? 1 + (port_no & (N_CHANNELS - 2))
- : 0);
+ /* The UINT32_MAX "reserved" port number uses the "ovs-system"'s
+ * channel, since it is not heavily loaded. */
+ int idx = (port_no >= dpif->uc_array_size) ? 0 : port_no;
return nl_sock_pid(dpif->channels[idx].sock);
}
}
}
}
-static void
-set_upcall_pids(struct dpif *dpif_)
-{
- struct dpif_linux *dpif = dpif_linux_cast(dpif_);
- struct dpif_port_dump port_dump;
- struct dpif_port port;
- int error;
-
- DPIF_PORT_FOR_EACH (&port, &port_dump, &dpif->dpif) {
- uint32_t upcall_pid = dpif_linux_port_get_pid(dpif_, port.port_no);
- struct dpif_linux_vport vport_request;
-
- dpif_linux_vport_init(&vport_request);
- vport_request.cmd = OVS_VPORT_CMD_SET;
- vport_request.dp_ifindex = dpif->dp_ifindex;
- vport_request.port_no = port.port_no;
- vport_request.upcall_pid = &upcall_pid;
- error = dpif_linux_vport_transact(&vport_request, NULL, NULL);
- if (!error) {
- VLOG_DBG("%s: assigning port %"PRIu32" to netlink pid %"PRIu32,
- dpif_name(&dpif->dpif), vport_request.port_no,
- upcall_pid);
- } else {
- VLOG_WARN_RL(&error_rl, "%s: failed to set upcall pid on port: %s",
- dpif_name(&dpif->dpif), strerror(error));
- }
- }
-}
-
static int
dpif_linux_recv_set(struct dpif *dpif_, bool enable)
{
if (!enable) {
destroy_channels(dpif);
} else {
- struct dpif_channel *ch;
- int error;
+ struct dpif_port_dump port_dump;
+ struct dpif_port port;
- dpif->epoll_fd = epoll_create(N_CHANNELS);
+ dpif->epoll_fd = epoll_create(10);
if (dpif->epoll_fd < 0) {
return errno;
}
- for (ch = dpif->channels; ch < &dpif->channels[N_CHANNELS]; ch++) {
- int indx = ch - dpif->channels;
- struct epoll_event event;
+ DPIF_PORT_FOR_EACH (&port, &port_dump, &dpif->dpif) {
+ struct dpif_linux_vport vport_request;
+ struct nl_sock *sock;
+ uint32_t upcall_pid;
+ int error;
- error = nl_sock_create(NETLINK_GENERIC, &ch->sock);
+ error = nl_sock_create(NETLINK_GENERIC, &sock);
if (error) {
- destroy_channels(dpif);
return error;
}
- memset(&event, 0, sizeof event);
- event.events = EPOLLIN;
- event.data.u32 = indx;
- if (epoll_ctl(dpif->epoll_fd, EPOLL_CTL_ADD, nl_sock_fd(ch->sock),
- &event) < 0) {
- error = errno;
- destroy_channels(dpif);
- return error;
+ upcall_pid = nl_sock_pid(sock);
+
+ dpif_linux_vport_init(&vport_request);
+ vport_request.cmd = OVS_VPORT_CMD_SET;
+ vport_request.dp_ifindex = dpif->dp_ifindex;
+ vport_request.port_no = port.port_no;
+ vport_request.upcall_pid = &upcall_pid;
+ error = dpif_linux_vport_transact(&vport_request, NULL, NULL);
+ if (!error) {
+ VLOG_DBG("%s: assigning port %"PRIu32" to netlink pid %"PRIu32,
+ dpif_name(&dpif->dpif), vport_request.port_no,
+ upcall_pid);
+ } else {
+ VLOG_WARN_RL(&error_rl,
+ "%s: failed to set upcall pid on port: %s",
+ dpif_name(&dpif->dpif), strerror(error));
+ nl_sock_destroy(sock);
+
+ if (error == ENODEV || error == ENOENT) {
+ /* This device isn't there, but keep trying the others. */
+ continue;
+ } else {
+ return error;
+ }
}
- memset(ch->sketches, 0, sizeof ch->sketches);
- ch->last_poll = LLONG_MIN;
+ error = add_channel(dpif, port.port_no, sock);
+ if (error) {
+ VLOG_INFO("%s: could not add channel for port %s",
+ dpif_name(dpif_), port.name);
+ nl_sock_destroy(sock);
+ return error;
+ }
}
-
- dpif->ready_mask = 0;
- dpif->next_scale = time_msec() + SCALE_INTERVAL;
}
- set_upcall_pids(dpif_);
-
return 0;
}
return EAGAIN;
}
- if (!dpif->ready_mask) {
- struct epoll_event events[N_CHANNELS];
+ if (dpif->event_offset >= dpif->n_events) {
int retval;
- int i;
+
+ dpif->event_offset = dpif->n_events = 0;
do {
- retval = epoll_wait(dpif->epoll_fd, events, N_CHANNELS, 0);
+ retval = epoll_wait(dpif->epoll_fd, dpif->epoll_events,
+ dpif->uc_array_size, 0);
} while (retval < 0 && errno == EINTR);
if (retval < 0) {
static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 1);
VLOG_WARN_RL(&rl, "epoll_wait failed (%s)", strerror(errno));
- }
-
- for (i = 0; i < retval; i++) {
- dpif->ready_mask |= 1u << events[i].data.u32;
+ } else if (retval > 0) {
+ dpif->n_events = retval;
}
}
- while (dpif->ready_mask) {
- int indx = ffs(dpif->ready_mask) - 1;
- struct dpif_channel *ch = &dpif->channels[indx];
+ while (dpif->event_offset < dpif->n_events) {
+ int idx = dpif->epoll_events[dpif->event_offset].data.u32;
+ struct dpif_channel *ch = &dpif->channels[idx];
- dpif->ready_mask &= ~(1u << indx);
+ dpif->event_offset++;
for (;;) {
int dp_ifindex;
error = parse_odp_packet(buf, upcall, &dp_ifindex);
if (!error && dp_ifindex == dpif->dp_ifindex) {
- const struct nlattr *in_port;
-
- in_port = nl_attr_find__(upcall->key, upcall->key_len,
- OVS_KEY_ATTR_IN_PORT);
- if (in_port) {
- update_sketch(ch, nl_attr_get_u32(in_port));
- }
return 0;
- }
- if (error) {
+ } else if (error) {
return error;
}
}
return;
}
- for (ch = dpif->channels; ch < &dpif->channels[N_CHANNELS]; ch++) {
- nl_sock_drain(ch->sock);
+ for (ch = dpif->channels; ch < &dpif->channels[dpif->uc_array_size]; ch++) {
+ if (ch->sock) {
+ nl_sock_drain(ch->sock);
+ }
}
}
stats->tcp_flags = flow->tcp_flags ? *flow->tcp_flags : 0;
}
\f
-/* Metwally "space-saving" algorithm implementation. */
-
-/* Updates 'ch' to record that a packet was received on 'port_no'. */
-static void
-update_sketch(struct dpif_channel *ch, uint32_t port_no)
-{
- struct dpif_sketch *sk;
-
- /* Find an existing counting element for 'port_no' or, if none, replace the
- * counting element with the fewest hits by 'port_no'. */
- for (sk = ch->sketches; ; sk++) {
- if (port_no == sk->port_no) {
- break;
- } else if (sk == &ch->sketches[N_SKETCHES - 1]) {
- sk->port_no = port_no;
- sk->error = sk->hits;
- break;
- }
- }
-
- /* Increment the hit count, then re-sort the counting elements (usually
- * nothing needs to be done). */
- sk->hits++;
- while (sk > ch->sketches && sk[-1].hits > sk->hits) {
- struct dpif_sketch tmp = sk[-1];
- sk[-1] = *sk;
- *sk = tmp;
- sk--;
- }
-}
-
-/* Divide the counts of all the the counting elements in 'dpif' by 2. See the
- * comment on SCALE_INTERVAL. */
-static void
-scale_sketches(struct dpif *dpif_)
-{
- struct dpif_linux *dpif = dpif_linux_cast(dpif_);
- struct dpif_channel *ch;
-
- for (ch = dpif->channels; ch < &dpif->channels[N_CHANNELS]; ch++) {
- struct dpif_sketch *sk;
-
- for (sk = ch->sketches; sk < &ch->sketches[N_SKETCHES]; sk++) {
- sk->hits /= 2;
- sk->error /= 2;
- }
- }
-}
-
/* Logs information about a packet that was recently lost in 'ch' (in
* 'dpif_'). */
static void
{
struct dpif_linux *dpif = dpif_linux_cast(dpif_);
static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 5);
- struct dpif_sketch *sk;
struct ds s;
if (VLOG_DROP_ERR(&rl)) {
ds_put_format(&s, " (last polled %lld ms ago)",
time_msec() - ch->last_poll);
}
- ds_put_cstr(&s, ", most frequent sources are");
- for (sk = ch->sketches; sk < &ch->sketches[N_SKETCHES]; sk++) {
- if (sk->hits) {
- struct dpif_port port;
-
- ds_put_format(&s, " %"PRIu32, sk->port_no);
- if (!dpif_port_query_by_number(dpif_, sk->port_no, &port)) {
- ds_put_format(&s, "(%s)", port.name);
- dpif_port_destroy(&port);
- }
- if (sk->error) {
- ds_put_format(&s, ": %u to %u,",
- sk->hits - sk->error, sk->hits);
- } else {
- ds_put_format(&s, ": %u,", sk->hits);
- }
- }
- }
- ds_chomp(&s, ',');
VLOG_WARN("%s: lost packet on channel %td%s",
dpif_name(dpif_), ch - dpif->channels, ds_cstr(&s));
git://git.onelab.eu / sliver-openvswitch.git / blobdiff