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neigh_table_tuner: tune all thresholds and limit growth #191

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neigh_table_tuner: tune all thresholds and limit growth #191

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6 changes: 5 additions & 1 deletion src/neigh_table_tuner.bpf.c
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Original file line number Diff line number Diff line change
Expand Up @@ -43,6 +43,8 @@ int BPF_PROG(bpftune_neigh_create, struct neigh_table *tbl,

new_tbl_stats.family = BPFTUNE_CORE_READ(tbl, family);
new_tbl_stats.entries = BPFTUNE_CORE_READ(tbl, entries.counter);
new_tbl_stats.thresh1 = BPFTUNE_CORE_READ(tbl, gc_thresh1);
new_tbl_stats.thresh2 = BPFTUNE_CORE_READ(tbl, gc_thresh2);
new_tbl_stats.max = BPFTUNE_CORE_READ(tbl, gc_thresh3);
if (dev) {
bpf_probe_read(&new_tbl_stats.dev, sizeof(new_tbl_stats.dev), dev);
Expand All @@ -55,12 +57,14 @@ int BPF_PROG(bpftune_neigh_create, struct neigh_table *tbl,
}
tbl_stats->entries = BPFTUNE_CORE_READ(tbl, entries.counter);
tbl_stats->gc_entries = BPFTUNE_CORE_READ(tbl, gc_entries.counter);
tbl_stats->thresh1 = BPFTUNE_CORE_READ(tbl, gc_thresh1);
tbl_stats->thresh2 = BPFTUNE_CORE_READ(tbl, gc_thresh2);
tbl_stats->max = BPFTUNE_CORE_READ(tbl, gc_thresh3);

/* exempt from gc entries are not subject to space constraints, but
* do take up table entries.
*/
if (NEARLY_FULL(tbl_stats->entries, tbl_stats->max)) {
if (NEARLY_FULL(tbl_stats->entries, tbl_stats->max) && (tbl_stats->max < MAX_THRESH3)) {
struct neigh_parms *parms = BPFTUNE_CORE_READ(n, parms);
struct net *net = BPFTUNE_CORE_READ(parms, net.net);

Expand Down
22 changes: 19 additions & 3 deletions src/neigh_table_tuner.c
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Original file line number Diff line number Diff line change
Expand Up @@ -77,7 +77,7 @@ void fini(struct bpftuner *tuner)
bpftuner_bpf_fini(tuner);
}

static int set_gc_thresh3(struct bpftuner *tuner, struct tbl_stats *stats)
static int increase_thresh(struct bpftuner *tuner, struct tbl_stats *stats)
{
char *tbl_name = stats->family == AF_INET ? "arp_cache" : "ndisc_cache";
/* Open raw socket for the NETLINK_ROUTE protocol */
Expand All @@ -89,6 +89,8 @@ static int set_gc_thresh3(struct bpftuner *tuner, struct tbl_stats *stats)
.ndtm_family = stats->family,
};
struct nl_msg *m = NULL, *parms = NULL;
int new_gc_thresh1 = 0;
int new_gc_thresh2 = 0;
int new_gc_thresh3 = 0;
int ret;

Expand Down Expand Up @@ -120,7 +122,19 @@ static int set_gc_thresh3(struct bpftuner *tuner, struct tbl_stats *stats)
NLA_PUT_STRING(m, NDTA_NAME, tbl_name);

new_gc_thresh3 = BPFTUNE_GROW_BY_DELTA(stats->max);

if (new_gc_thresh3 >= MAX_THRESH3) {
new_gc_thresh3 = MAX_THRESH3;
new_gc_thresh2 = MAX_THRESH2;
new_gc_thresh1 = MAX_THRESH1;
}
else {
new_gc_thresh2 = BPFTUNE_GROW_BY_DELTA(stats->thresh2);
new_gc_thresh1 = BPFTUNE_GROW_BY_DELTA(stats->thresh1);
}
NLA_PUT_U32(m, NDTA_THRESH3, new_gc_thresh3);
NLA_PUT_U32(m, NDTA_THRESH2, new_gc_thresh2);
NLA_PUT_U32(m, NDTA_THRESH1, new_gc_thresh1);

parms = nlmsg_alloc();
if (!parms) {
Expand Down Expand Up @@ -152,8 +166,10 @@ static int set_gc_thresh3(struct bpftuner *tuner, struct tbl_stats *stats)
stats->dev, strerror(-ret));
} else {
bpftuner_tunable_update(tuner, tunable, NEIGH_TABLE_FULL, 0,
"updated gc_thresh3 for %s table, dev '%s' (ifindex %d) from %ld to %ld\n",
"updated thresholds for %s table, dev '%s' (ifindex %d) thresh1: %ld to %ld, thresh2: %ld to %ld, thresh3: %ld to %ld\n",
tbl_name, stats->dev, stats->ifindex,
stats->thresh1, new_gc_thresh1,
stats->thresh2, new_gc_thresh2,
stats->max, new_gc_thresh3);
}
return ret;
Expand All @@ -169,7 +185,7 @@ void event_handler(struct bpftuner *tuner,
case NEIGH_TABLE_FULL:
if (bpftune_cap_add())
return;
set_gc_thresh3(tuner, stats);
increase_thresh(tuner, stats);
bpftune_cap_drop();
break;
default:
Expand Down
6 changes: 6 additions & 0 deletions src/neigh_table_tuner.h
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Original file line number Diff line number Diff line change
Expand Up @@ -23,6 +23,10 @@
#define IFNAMSIZ 16
#endif

#define MAX_THRESH1 4096
#define MAX_THRESH2 16384
#define MAX_THRESH3 32768

enum neigh_table_tunables {
NEIGH_TABLE_IPV4_GC_INTERVAL,
NEIGH_TABLE_IPV4_GC_STALE_TIME,
Expand All @@ -45,6 +49,8 @@ struct tbl_stats {
int family;
int entries;
int gc_entries;
int thresh1;
int thresh2;
int max;
int ifindex;
char dev[IFNAMSIZ];
Expand Down