[src/trunk]: src/sys/net Make bpf_gstats percpu

[ozaki-r <ozaki-r%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/7a81b31cf6fb
branches:  trunk
changeset: 821314:7a81b31cf6fb
user:      ozaki-r <ozaki-r%NetBSD.org@localhost>
date:      Wed Feb 01 08:15:15 2017 +0000

description:
Make bpf_gstats percpu

diffstat:

 sys/net/bpf.c |  59 +++++++++++++++++++++++++++++++++++++++++++++++++----------
 1 files changed, 49 insertions(+), 10 deletions(-)

diffs (129 lines):

diff -r f39dd631f466 -r 7a81b31cf6fb sys/net/bpf.c
--- a/sys/net/bpf.c     Wed Feb 01 08:13:45 2017 +0000
+++ b/sys/net/bpf.c     Wed Feb 01 08:15:15 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: bpf.c,v 1.209 2017/02/01 08:13:45 ozaki-r Exp $        */
+/*     $NetBSD: bpf.c,v 1.210 2017/02/01 08:15:15 ozaki-r Exp $        */
 
 /*
  * Copyright (c) 1990, 1991, 1993
@@ -39,7 +39,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: bpf.c,v 1.209 2017/02/01 08:13:45 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: bpf.c,v 1.210 2017/02/01 08:15:15 ozaki-r Exp $");
 
 #if defined(_KERNEL_OPT)
 #include "opt_bpf.h"
@@ -76,6 +76,7 @@
 #include <sys/sysctl.h>
 #include <sys/kauth.h>
 #include <sys/syslog.h>
+#include <sys/percpu.h>
 
 #include <net/if.h>
 #include <net/slip.h>
@@ -120,7 +121,15 @@
 /*
  * Global BPF statistics returned by net.bpf.stats sysctl.
  */
-static struct bpf_stat bpf_gstats;
+static struct percpu   *bpf_gstats_percpu; /* struct bpf_stat */
+
+#define BPF_STATINC(id)                                        \
+       {                                               \
+               struct bpf_stat *__stats =              \
+                   percpu_getref(bpf_gstats_percpu);   \
+               __stats->bs_##id++;                     \
+               percpu_putref(bpf_gstats_percpu);       \
+       }
 
 /*
  * Use a mutex to avoid a race condition between gathering the stats/peers
@@ -466,9 +475,7 @@
        PSLIST_INIT(&bpf_iflist);
        PSLIST_INIT(&bpf_dlist);
 
-       bpf_gstats.bs_recv = 0;
-       bpf_gstats.bs_drop = 0;
-       bpf_gstats.bs_capt = 0;
+       bpf_gstats_percpu = percpu_alloc(sizeof(struct bpf_stat));
 
        return;
 }
@@ -1496,7 +1503,7 @@
                        continue;
                }
                d->bd_rcount++;
-               bpf_gstats.bs_recv++;
+               BPF_STATINC(recv);
 
                if (d->bd_jitcode)
                        slen = d->bd_jitcode(NULL, &args);
@@ -1787,7 +1794,7 @@
        int do_wakeup = 0;
 
        ++d->bd_ccount;
-       ++bpf_gstats.bs_capt;
+       BPF_STATINC(capt);
        /*
         * Figure out how many bytes to move.  If the packet is
         * greater or equal to the snapshot length, transfer that
@@ -1826,7 +1833,7 @@
                         * so drop the packet.
                         */
                        ++d->bd_dcount;
-                       ++bpf_gstats.bs_drop;
+                       BPF_STATINC(drop);
                        return;
                }
                ROTATE_BUFFERS(d);
@@ -2244,6 +2251,38 @@
        return (error);
 }
 
+static void
+bpf_stats(void *p, void *arg, struct cpu_info *ci __unused)
+{
+       struct bpf_stat *const stats = p;
+       struct bpf_stat *sum = arg;
+
+       sum->bs_recv += stats->bs_recv;
+       sum->bs_drop += stats->bs_drop;
+       sum->bs_capt += stats->bs_capt;
+}
+
+static int
+bpf_sysctl_gstats_handler(SYSCTLFN_ARGS)
+{
+       struct sysctlnode node;
+       int error;
+       struct bpf_stat sum;
+
+       memset(&sum, 0, sizeof(sum));
+       node = *rnode;
+
+       percpu_foreach(bpf_gstats_percpu, bpf_stats, &sum);
+
+       node.sysctl_data = &sum;
+       node.sysctl_size = sizeof(sum);
+       error = sysctl_lookup(SYSCTLFN_CALL(&node));
+       if (error != 0 || newp == NULL)
+               return error;
+
+       return 0;
+}
+
 static struct sysctllog *bpf_sysctllog;
 static void
 sysctl_net_bpf_setup(void)
@@ -2276,7 +2315,7 @@
                        CTLFLAG_PERMANENT,
                        CTLTYPE_STRUCT, "stats",
                        SYSCTL_DESCR("BPF stats"),
-                       NULL, 0, &bpf_gstats, sizeof(bpf_gstats),
+                       bpf_sysctl_gstats_handler, 0, NULL, 0,
                        CTL_NET, node->sysctl_num, CTL_CREATE, CTL_EOL);
                sysctl_createv(&bpf_sysctllog, 0, NULL, NULL,
                        CTLFLAG_PERMANENT,