]> git.ipfire.org Git - thirdparty/kernel/linux.git/commitdiff
tools: ynltool: add traffic distribution balance
authorJakub Kicinski <kuba@kernel.org>
Fri, 7 Nov 2025 16:22:27 +0000 (08:22 -0800)
committerPaolo Abeni <pabeni@redhat.com>
Tue, 11 Nov 2025 11:21:04 +0000 (12:21 +0100)
The main if not only use case for per-queue stats today is checking
for traffic imbalance. Add simple traffic balance analysis to qstats.

 $ ynltool qstat balance
 eth0 rx 44 queues:
  rx-packets  : cv=6.9% ns=24.2% stddev=512006493
                min=6278921110 max=8011570575 mean=7437054644
  rx-bytes    : cv=6.9% ns=24.1% stddev=759670503060
                min=9326315769440 max=11884393670786 mean=11035439201354
  ...

  $ ynltool -j qstat balance | jq
  [
   {
    "ifname": "eth0",
    "ifindex": 2,
    "queue-type": "rx",
    "rx-packets": {
      "queue-count": 44,
      "min": 6278301665,
      "max": 8010780185,
      "mean": 7.43635E+9,
      "stddev": 5.12012E+8,
      "coefficient-of-variation": 6.88525,
      "normalized-spread": 24.249
    },
   ...

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Link: https://patch.msgid.link/20251107162227.980672-5-kuba@kernel.org
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
tools/net/ynl/ynltool/Makefile
tools/net/ynl/ynltool/qstats.c

index 11240740ed8105410e581cb71ccd4d2f5df3d9eb..86c30b7420cf74208f43bd31ede1713c15018847 100644 (file)
@@ -31,7 +31,7 @@ Q = @
 
 $(YNLTOOL): ../libynl.a $(OBJS)
        $(Q)echo -e "\tLINK $@"
-       $(Q)$(CC) $(CFLAGS) -o $@ $(OBJS) ../libynl.a -lmnl
+       $(Q)$(CC) $(CFLAGS) -o $@ $(OBJS) ../libynl.a -lmnl -lm
 
 %.o: %.c ../libynl.a
        $(Q)echo -e "\tCC $@"
index fcdbb6d9a8525d972739c8721d04523609d852e7..31fb45709ffab16d7788a9c3f3ba0b5dd4792756 100644 (file)
@@ -5,6 +5,7 @@
 #include <string.h>
 #include <errno.h>
 #include <net/if.h>
+#include <math.h>
 
 #include <ynl.h>
 #include "netdev-user.h"
 
 static enum netdev_qstats_scope scope; /* default - device */
 
+struct queue_balance {
+       unsigned int ifindex;
+       enum netdev_queue_type type;
+       unsigned int queue_count;
+       __u64 *rx_packets;
+       __u64 *rx_bytes;
+       __u64 *tx_packets;
+       __u64 *tx_bytes;
+};
+
 static void print_json_qstats(struct netdev_qstats_get_list *qstats)
 {
        jsonw_start_array(json_wtr);
@@ -293,6 +304,283 @@ exit_close:
        return ret;
 }
 
+static void compute_stats(__u64 *values, unsigned int count,
+                         double *mean, double *stddev, __u64 *min, __u64 *max)
+{
+       double sum = 0.0, variance = 0.0;
+       unsigned int i;
+
+       *min = ~0ULL;
+       *max = 0;
+
+       if (count == 0) {
+               *mean = 0;
+               *stddev = 0;
+               *min = 0;
+               return;
+       }
+
+       for (i = 0; i < count; i++) {
+               sum += values[i];
+               if (values[i] < *min)
+                       *min = values[i];
+               if (values[i] > *max)
+                       *max = values[i];
+       }
+
+       *mean = sum / count;
+
+       if (count > 1) {
+               for (i = 0; i < count; i++) {
+                       double diff = values[i] - *mean;
+
+                       variance += diff * diff;
+               }
+               *stddev = sqrt(variance / (count - 1));
+       } else {
+               *stddev = 0;
+       }
+}
+
+static void print_balance_stats(const char *name, enum netdev_queue_type type,
+                               __u64 *values, unsigned int count)
+{
+       double mean, stddev, cv, ns;
+       __u64 min, max;
+
+       if ((name[0] == 'r' && type != NETDEV_QUEUE_TYPE_RX) ||
+           (name[0] == 't' && type != NETDEV_QUEUE_TYPE_TX))
+               return;
+
+       compute_stats(values, count, &mean, &stddev, &min, &max);
+
+       cv = mean > 0 ? (stddev / mean) * 100.0 : 0.0;
+       ns = min + max > 0 ? (double)2 * (max - min) / (max + min) * 100 : 0.0;
+
+       printf("  %-12s: cv=%.1f%% ns=%.1f%% stddev=%.0f\n",
+              name, cv, ns, stddev);
+       printf("  %-12s  min=%llu max=%llu mean=%.0f\n",
+              "", min, max, mean);
+}
+
+static void
+print_balance_stats_json(const char *name, enum netdev_queue_type type,
+                        __u64 *values, unsigned int count)
+{
+       double mean, stddev, cv, ns;
+       __u64 min, max;
+
+       if ((name[0] == 'r' && type != NETDEV_QUEUE_TYPE_RX) ||
+           (name[0] == 't' && type != NETDEV_QUEUE_TYPE_TX))
+               return;
+
+       compute_stats(values, count, &mean, &stddev, &min, &max);
+
+       cv = mean > 0 ? (stddev / mean) * 100.0 : 0.0;
+       ns = min + max > 0 ? (double)2 * (max - min) / (max + min) * 100 : 0.0;
+
+       jsonw_name(json_wtr, name);
+       jsonw_start_object(json_wtr);
+       jsonw_uint_field(json_wtr, "queue-count", count);
+       jsonw_uint_field(json_wtr, "min", min);
+       jsonw_uint_field(json_wtr, "max", max);
+       jsonw_float_field(json_wtr, "mean", mean);
+       jsonw_float_field(json_wtr, "stddev", stddev);
+       jsonw_float_field(json_wtr, "coefficient-of-variation", cv);
+       jsonw_float_field(json_wtr, "normalized-spread", ns);
+       jsonw_end_object(json_wtr);
+}
+
+static int cmp_ifindex_type(const void *a, const void *b)
+{
+       const struct netdev_qstats_get_rsp *qa = a;
+       const struct netdev_qstats_get_rsp *qb = b;
+
+       if (qa->ifindex != qb->ifindex)
+               return qa->ifindex - qb->ifindex;
+       if (qa->queue_type != qb->queue_type)
+               return qa->queue_type - qb->queue_type;
+       return qa->queue_id - qb->queue_id;
+}
+
+static int do_balance(int argc, char **argv __attribute__((unused)))
+{
+       struct netdev_qstats_get_list *qstats;
+       struct netdev_qstats_get_req *req;
+       struct netdev_qstats_get_rsp **sorted;
+       struct ynl_error yerr;
+       struct ynl_sock *ys;
+       unsigned int count = 0;
+       unsigned int i, j;
+       int ret = 0;
+
+       if (argc > 0) {
+               p_err("balance command takes no arguments");
+               return -1;
+       }
+
+       ys = ynl_sock_create(&ynl_netdev_family, &yerr);
+       if (!ys) {
+               p_err("YNL: %s", yerr.msg);
+               return -1;
+       }
+
+       req = netdev_qstats_get_req_alloc();
+       if (!req) {
+               p_err("failed to allocate qstats request");
+               ret = -1;
+               goto exit_close;
+       }
+
+       /* Always use queue scope for balance analysis */
+       netdev_qstats_get_req_set_scope(req, NETDEV_QSTATS_SCOPE_QUEUE);
+
+       qstats = netdev_qstats_get_dump(ys, req);
+       netdev_qstats_get_req_free(req);
+       if (!qstats) {
+               p_err("failed to get queue stats: %s", ys->err.msg);
+               ret = -1;
+               goto exit_close;
+       }
+
+       /* Count and sort queues */
+       ynl_dump_foreach(qstats, qs)
+               count++;
+
+       if (count == 0) {
+               if (json_output)
+                       jsonw_start_array(json_wtr);
+               else
+                       printf("No queue statistics available\n");
+               goto exit_free_qstats;
+       }
+
+       sorted = calloc(count, sizeof(*sorted));
+       if (!sorted) {
+               p_err("failed to allocate sorted array");
+               ret = -1;
+               goto exit_free_qstats;
+       }
+
+       i = 0;
+       ynl_dump_foreach(qstats, qs)
+               sorted[i++] = qs;
+
+       qsort(sorted, count, sizeof(*sorted), cmp_ifindex_type);
+
+       if (json_output)
+               jsonw_start_array(json_wtr);
+
+       /* Process each device/queue-type combination */
+       i = 0;
+       while (i < count) {
+               __u64 *rx_packets, *rx_bytes, *tx_packets, *tx_bytes;
+               enum netdev_queue_type type = sorted[i]->queue_type;
+               unsigned int ifindex = sorted[i]->ifindex;
+               unsigned int queue_count = 0;
+               char ifname[IF_NAMESIZE];
+               const char *name;
+
+               /* Count queues for this device/type */
+               for (j = i; j < count && sorted[j]->ifindex == ifindex &&
+                    sorted[j]->queue_type == type; j++)
+                       queue_count++;
+
+               /* Skip if no packets/bytes (inactive queues) */
+               if (!sorted[i]->_present.rx_packets &&
+                   !sorted[i]->_present.rx_bytes &&
+                   !sorted[i]->_present.tx_packets &&
+                   !sorted[i]->_present.tx_bytes)
+                       goto next_ifc;
+
+               /* Allocate arrays for statistics */
+               rx_packets = calloc(queue_count, sizeof(*rx_packets));
+               rx_bytes   = calloc(queue_count, sizeof(*rx_bytes));
+               tx_packets = calloc(queue_count, sizeof(*tx_packets));
+               tx_bytes   = calloc(queue_count, sizeof(*tx_bytes));
+
+               if (!rx_packets || !rx_bytes || !tx_packets || !tx_bytes) {
+                       p_err("failed to allocate statistics arrays");
+                       free(rx_packets);
+                       free(rx_bytes);
+                       free(tx_packets);
+                       free(tx_bytes);
+                       ret = -1;
+                       goto exit_free_sorted;
+               }
+
+               /* Collect statistics */
+               for (j = 0; j < queue_count; j++) {
+                       rx_packets[j] = sorted[i + j]->_present.rx_packets ?
+                                       sorted[i + j]->rx_packets : 0;
+                       rx_bytes[j] = sorted[i + j]->_present.rx_bytes ?
+                                     sorted[i + j]->rx_bytes : 0;
+                       tx_packets[j] = sorted[i + j]->_present.tx_packets ?
+                                       sorted[i + j]->tx_packets : 0;
+                       tx_bytes[j] = sorted[i + j]->_present.tx_bytes ?
+                                     sorted[i + j]->tx_bytes : 0;
+               }
+
+               name = if_indextoname(ifindex, ifname);
+
+               if (json_output) {
+                       jsonw_start_object(json_wtr);
+                       if (name)
+                               jsonw_string_field(json_wtr, "ifname", name);
+                       jsonw_uint_field(json_wtr, "ifindex", ifindex);
+                       jsonw_string_field(json_wtr, "queue-type",
+                                          netdev_queue_type_str(type));
+
+                       print_balance_stats_json("rx-packets", type,
+                                                rx_packets, queue_count);
+                       print_balance_stats_json("rx-bytes", type,
+                                                rx_bytes, queue_count);
+                       print_balance_stats_json("tx-packets", type,
+                                                tx_packets, queue_count);
+                       print_balance_stats_json("tx-bytes", type,
+                                                tx_bytes, queue_count);
+
+                       jsonw_end_object(json_wtr);
+               } else {
+                       if (name)
+                               printf("%s", name);
+                       else
+                               printf("ifindex:%u", ifindex);
+                       printf(" %s %d queues:\n",
+                              netdev_queue_type_str(type), queue_count);
+
+                       print_balance_stats("rx-packets", type,
+                                           rx_packets, queue_count);
+                       print_balance_stats("rx-bytes", type,
+                                           rx_bytes, queue_count);
+                       print_balance_stats("tx-packets", type,
+                                           tx_packets, queue_count);
+                       print_balance_stats("tx-bytes", type,
+                                           tx_bytes, queue_count);
+                       printf("\n");
+               }
+
+               free(rx_packets);
+               free(rx_bytes);
+               free(tx_packets);
+               free(tx_bytes);
+
+next_ifc:
+               i += queue_count;
+       }
+
+       if (json_output)
+               jsonw_end_array(json_wtr);
+
+exit_free_sorted:
+       free(sorted);
+exit_free_qstats:
+       netdev_qstats_get_list_free(qstats);
+exit_close:
+       ynl_sock_destroy(ys);
+       return ret;
+}
+
 static int do_help(int argc __attribute__((unused)),
                   char **argv __attribute__((unused)))
 {
@@ -304,6 +592,7 @@ static int do_help(int argc __attribute__((unused)),
        fprintf(stderr,
                "Usage: %s qstats { COMMAND | help }\n"
                "       %s qstats [ show ] [ OPTIONS ]\n"
+               "       %s qstats balance\n"
                "\n"
                "       OPTIONS := { scope queue | group-by { device | queue } }\n"
                "\n"
@@ -312,14 +601,16 @@ static int do_help(int argc __attribute__((unused)),
                "       show scope queue      - Display per-queue statistics\n"
                "       show group-by device  - Display device-aggregated statistics (default)\n"
                "       show group-by queue   - Display per-queue statistics\n"
+               "       balance               - Analyze traffic distribution balance.\n"
                "",
-               bin_name, bin_name);
+               bin_name, bin_name, bin_name);
 
        return 0;
 }
 
 static const struct cmd qstats_cmds[] = {
        { "show",       do_show },
+       { "balance",    do_balance },
        { "help",       do_help },
        { 0 }
 };