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fix high cpu usage when there are >10k addresses on the host
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Signed-off-by: zhangzujian <[email protected]>
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@zhangzujian
zhangzujian committed Jan 19, 2024
1 parent 1d2b528 commit 8a4f08e
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Showing 3 changed files with 188 additions and 65 deletions.
14 changes: 5 additions & 9 deletions lib/netdev-linux.c
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Original file line number Diff line number Diff line change
Expand Up @@ -3322,19 +3322,15 @@ netdev_linux_get_addr_list(const struct netdev *netdev_,
struct in6_addr **addr, struct in6_addr **mask, int *n_cnt)
{
struct netdev_linux *netdev = netdev_linux_cast(netdev_);
int ifindex;
int error;

ovs_mutex_lock(&netdev->mutex);
if (netdev_linux_netnsid_is_remote(netdev)) {
error = EOPNOTSUPP;
goto exit;
error = get_ifindex(netdev, &ifindex);
if (error) {
return error;
}

error = netdev_get_addrs(netdev_get_name(netdev_), addr, mask, n_cnt);

exit:
ovs_mutex_unlock(&netdev->mutex);
return error;
return netdev_get_addrs(ifindex, addr, mask, n_cnt);
}

static void
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237 changes: 182 additions & 55 deletions lib/netdev.c
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Original file line number Diff line number Diff line change
Expand Up @@ -29,6 +29,10 @@
#include <ifaddrs.h>
#include <net/if.h>
#include <sys/ioctl.h>
#include <asm/types.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <sys/socket.h>
#endif

#include "cmap.h"
Expand Down Expand Up @@ -2166,86 +2170,209 @@ netdev_get_change_seq(const struct netdev *netdev)
#ifndef _WIN32
/* This implementation is shared by Linux and BSD. */

static struct ifaddrs *if_addr_list;
struct linux_addr_list {
int if_index;
struct in6_addr addr, mask;
struct linux_addr_list *next;
};

struct netdev_linux_addr_list {
int if_index, count;
struct in6_addr *addr_array, *mask_array;
struct hmap_node hmap_node;
};

static struct hmap *if_addr_list = NULL;
static struct ovs_mutex if_addr_list_lock = OVS_MUTEX_INITIALIZER;

static struct netdev_linux_addr_list *
find_if_addr_list(struct hmap *addr_list, int if_index, uint32_t hash)
{
struct netdev_linux_addr_list *l;
HMAP_FOR_EACH_IN_BUCKET (l, hmap_node, hash, addr_list) {
if (l->if_index == if_index) {
return l;
}
}
return NULL;
}

static int
netdev_linux_get_addr_list(struct hmap **addr_list)
{
struct nl_dump dump;
struct ifaddrmsg *ifa;
uint64_t reply_stub[NL_DUMP_BUFSIZE / 8];
struct ofpbuf request, reply, buf;
uint32_t hash;
int error = 0;

ofpbuf_init(&request, 0);
nl_msg_put_nlmsghdr(&request, sizeof(struct ifaddrmsg),
RTM_GETADDR, NLM_F_REQUEST);
ifa = ofpbuf_put_zeros(&request, sizeof(struct ifaddrmsg));
ifa->ifa_family = AF_UNSPEC;

nl_dump_start(&dump, NETLINK_ROUTE, &request);
ofpbuf_uninit(&request);

*addr_list = xmalloc(sizeof(struct hmap));
hmap_init(*addr_list);

struct linux_addr_list *all_addrs = NULL;
struct linux_addr_list **p = &all_addrs;

ofpbuf_use_stub(&buf, reply_stub, sizeof reply_stub);
while (nl_dump_next(&dump, &reply, &buf)) {
bool parsed, ipv4 = false;

// IFA_ADDRESS raw protocol address interface address
// IFA_LOCAL raw protocol address local address
// IFA_LABEL asciiz string name of the interface
// IFA_BROADCAST raw protocol address broadcast address
// IFA_ANYCAST raw protocol address anycast address
// IFA_CACHEINFO struct ifa_cacheinfo Address information

static const struct nl_policy policy[] = {
[IFA_ADDRESS] = { .type = NL_A_U32, .optional = false },
[IFA_LOCAL] = { .type = NL_A_U32, .optional = true },
[IFA_LABEL] = { .type = NL_A_STRING, .optional = true },
[IFA_BROADCAST] = { .type = NL_A_U32, .optional = true },
[IFA_ANYCAST] = { .type = NL_A_U32, .optional = true },
[IFA_CACHEINFO] = { .type = NL_A_U128, .optional = true },
};

static const struct nl_policy policy6[] = {
[IFA_ADDRESS] = { .type = NL_A_IPV6, .optional = false },
[IFA_LOCAL] = { .type = NL_A_IPV6, .optional = true },
[IFA_LABEL] = { .type = NL_A_STRING, .optional = true },
[IFA_BROADCAST] = { .type = NL_A_IPV6, .optional = true },
[IFA_ANYCAST] = { .type = NL_A_IPV6, .optional = true },
[IFA_CACHEINFO] = { .type = NL_A_U128, .optional = true },
};

struct nlattr *attrs[ARRAY_SIZE(policy)];
const struct ifaddrmsg *msg;

msg = ofpbuf_at(&reply, NLMSG_HDRLEN, sizeof *msg);
if (msg->ifa_family == AF_INET) {
parsed = nl_policy_parse(&reply,
NLMSG_HDRLEN + sizeof(struct ifaddrmsg),
policy, attrs, ARRAY_SIZE(policy));
ipv4 = true;
} else if (msg->ifa_family == AF_INET6) {
parsed = nl_policy_parse(&reply,
NLMSG_HDRLEN + sizeof(struct ifaddrmsg),
policy6, attrs, ARRAY_SIZE(policy6));
} else {
VLOG_DBG_RL(&rl,
"received non AF_INET/AF_INET6"
"rtnetlink address message");
goto out;
}

if (parsed) {
*p = xzalloc(sizeof(struct linux_addr_list));
(*p)->if_index = msg->ifa_index;
if (ipv4) {
ovs_be32 addr = nl_attr_get_be32(attrs[IFA_ADDRESS]);
ovs_be32 mask = be32_prefix_mask(msg->ifa_prefixlen);
(*p)->addr = in6_addr_mapped_ipv4(addr);
(*p)->mask = in6_addr_mapped_ipv4(mask);
} else {
(*p)->addr = nl_attr_get_in6_addr(attrs[IFA_ADDRESS]);
(*p)->mask = ipv6_create_mask(msg->ifa_prefixlen);
}
p = &((*p)->next);

struct netdev_linux_addr_list *list;
hash = hash_int(msg->ifa_index, 0);
list = find_if_addr_list(*addr_list, msg->ifa_index, hash);
if (!list) {
list = xzalloc(sizeof *list);
list->if_index = msg->ifa_index;
list->count = 1;
hmap_insert(*addr_list, &list->hmap_node, hash);
} else {
list->count += 1;
}
} else {
VLOG_DBG_RL(&rl, "received unparseable rtnetlink address message");
goto out;
}
}
ofpbuf_uninit(&buf);

error = nl_dump_done(&dump);

out:
struct linux_addr_list *addr, *next;
for (addr = all_addrs; addr; addr = next) {
next = addr->next;
struct netdev_linux_addr_list *list;
hash = hash_int(addr->if_index, 0);
list = find_if_addr_list(*addr_list, addr->if_index, hash);
if (!list->addr_array) {
list->addr_array = xzalloc(sizeof(struct in6_addr) * list->count);
list->mask_array = xzalloc(sizeof(struct in6_addr) * list->count);
list->count = 0;
}
list->addr_array[list->count] = addr->addr;
list->mask_array[list->count] = addr->mask;
list->count += 1;
free(addr);
}

return error;
}

void
netdev_get_addrs_list_flush(void)
{
ovs_mutex_lock(&if_addr_list_lock);
if (if_addr_list) {
freeifaddrs(if_addr_list);
struct netdev_linux_addr_list *list;
HMAP_FOR_EACH_SAFE (list, hmap_node, if_addr_list) {
free(list->addr_array);
free(list->mask_array);
free(list);
}
hmap_destroy(if_addr_list);
free(if_addr_list);
if_addr_list = NULL;
}
ovs_mutex_unlock(&if_addr_list_lock);
}

int
netdev_get_addrs(const char dev[], struct in6_addr **paddr,
netdev_get_addrs(const int ifindex, struct in6_addr **paddr,
struct in6_addr **pmask, int *n_in)
{
struct in6_addr *addr_array, *mask_array;
const struct ifaddrs *ifa;
int cnt = 0, i = 0;
int retries = 3;
int cnt = 0;

ovs_mutex_lock(&if_addr_list_lock);
if (!if_addr_list) {
int err;

retry:
err = getifaddrs(&if_addr_list);
if (!if_addr_list) {
int err = netdev_linux_get_addr_list(&if_addr_list);
if (err) {
ovs_mutex_unlock(&if_addr_list_lock);
return -err;
}
retries--;
}

for (ifa = if_addr_list; ifa; ifa = ifa->ifa_next) {
if (!ifa->ifa_name) {
if (retries) {
/* Older versions of glibc have a bug on race condition with
* address addition which may cause one of the returned
* ifa_name values to be NULL. In such case, we know that we've
* got an inconsistent dump. Retry but beware of an endless
* loop. From glibc 2.28 and beyond, this workaround is not
* needed and should be eventually removed. */
freeifaddrs(if_addr_list);
goto retry;
} else {
VLOG_WARN("Proceeding with an inconsistent dump of "
"interfaces from the kernel. Some may be missing");
}
}
if (ifa->ifa_addr && ifa->ifa_name && ifa->ifa_netmask) {
int family;

family = ifa->ifa_addr->sa_family;
if (family == AF_INET || family == AF_INET6) {
if (!strncmp(ifa->ifa_name, dev, IFNAMSIZ)) {
cnt++;
}
}
}
}

if (!cnt) {
ovs_mutex_unlock(&if_addr_list_lock);
return EADDRNOTAVAIL;
}
addr_array = xzalloc(sizeof *addr_array * cnt);
mask_array = xzalloc(sizeof *mask_array * cnt);
for (ifa = if_addr_list; ifa; ifa = ifa->ifa_next) {
if (ifa->ifa_name
&& ifa->ifa_addr
&& ifa->ifa_netmask
&& !strncmp(ifa->ifa_name, dev, IFNAMSIZ)
&& sa_is_ip(ifa->ifa_addr)) {
addr_array[i] = sa_get_address(ifa->ifa_addr);
mask_array[i] = sa_get_address(ifa->ifa_netmask);
i++;
}
struct netdev_linux_addr_list *list;
uint32_t hash = hash_int(ifindex, 0);
list = find_if_addr_list(if_addr_list, ifindex, hash);
if (list) {
cnt = list->count;
}
size_t size = sizeof *addr_array * cnt;
addr_array = xmalloc(size);
mask_array = xmalloc(size);
if (list) {
memcpy(addr_array, list->addr_array, size);
memcpy(mask_array, list->addr_array, size);
}
ovs_mutex_unlock(&if_addr_list_lock);
if (paddr) {
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2 changes: 1 addition & 1 deletion lib/netdev.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -355,7 +355,7 @@ extern struct seq *tnl_conf_seq;

#ifndef _WIN32
void netdev_get_addrs_list_flush(void);
int netdev_get_addrs(const char dev[], struct in6_addr **paddr,
int netdev_get_addrs(const int ifindex, struct in6_addr **paddr,
struct in6_addr **pmask, int *n_in6);
#endif

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