[PATCH V1 libibverbs 8/8] Add timestamp support in rc_pingpong

Yishai Hadas
2016-02-24T09:42:04Z

Add timestamp support in rc_pingpong, it can serve as some example
of using ibv_create_cq_ex and ibv_poll_cq_ex verbs.

Signed-off-by: Yishai Hadas <yishaih-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Reviewed-by: Matan Barak <matanb-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
---
examples/rc_pingpong.c | 130 +++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 114 insertions(+), 16 deletions(-)

diff --git a/examples/rc_pingpong.c b/examples/rc_pingpong.c
index 90a8320..bffcfe5 100644
--- a/examples/rc_pingpong.c
+++ b/examples/rc_pingpong.c
@@ -49,6 +49,14 @@

#include "pingpong.h"

+#ifndef max
+#define max(x, y) (((x) > (y)) ? (x) : (y))
+#endif
+
+#ifndef min
+#define min(x, y) (((x) < (y)) ? (x) : (y))
+#endif
+
enum {
PINGPONG_RECV_WRID = 1,
PINGPONG_SEND_WRID = 2,
@@ -56,6 +64,7 @@ enum {

static int page_size;
static int use_odp;
+static int use_ts;

struct pingpong_context {
struct ibv_context *context;
@@ -70,6 +79,7 @@ struct pingpong_context {
int rx_depth;
int pending;
struct ibv_port_attr portinfo;
+ uint64_t completion_timestamp_mask;
};

struct pingpong_dest {
@@ -357,7 +367,7 @@ static struct pingpong_context *pp_init_ctx(struct ibv_device *ib_dev, int size,
goto clean_comp_channel;
}

- if (use_odp) {
+ if (use_odp || use_ts) {
const uint32_t rc_caps_mask = IBV_ODP_SUPPORT_SEND |
IBV_ODP_SUPPORT_RECV;
struct ibv_device_attr_ex attrx;
@@ -367,12 +377,22 @@ static struct pingpong_context *pp_init_ctx(struct ibv_device *ib_dev, int size,
goto clean_comp_channel;
}

- if (!(attrx.odp_caps.general_caps & IBV_ODP_SUPPORT) ||
- (attrx.odp_caps.per_transport_caps.rc_odp_caps & rc_caps_mask) != rc_caps_mask) {
- fprintf(stderr, "The device isn't ODP capable or does not support RC send and receive with ODP\n");
- goto clean_comp_channel;
+ if (use_odp) {
+ if (!(attrx.odp_caps.general_caps & IBV_ODP_SUPPORT) ||
+ (attrx.odp_caps.per_transport_caps.rc_odp_caps & rc_caps_mask) != rc_caps_mask) {
+ fprintf(stderr, "The device isn't ODP capable or does not support RC send and receive with ODP\n");
+ goto clean_comp_channel;
+ }
+ access_flags |= IBV_ACCESS_ON_DEMAND;
+ }
+
+ if (use_ts) {
+ if (!attrx.completion_timestamp_mask) {
+ fprintf(stderr, "The device isn't completion timestamp capable\n");
+ goto clean_comp_channel;
+ }
+ ctx->completion_timestamp_mask = attrx.completion_timestamp_mask;
}
- access_flags |= IBV_ACCESS_ON_DEMAND;
}
ctx->mr = ibv_reg_mr(ctx->pd, ctx->buf, size, access_flags);

@@ -381,8 +401,23 @@ static struct pingpong_context *pp_init_ctx(struct ibv_device *ib_dev, int size,
goto clean_pd;
}

- ctx->cq = ibv_create_cq(ctx->context, rx_depth + 1, NULL,
+ if (use_ts) {
+ struct ibv_cq_init_attr_ex attr_ex = {
+ .cqe = rx_depth + 1,
+ .cq_context = NULL,
+ .channel = ctx->channel,
+ .comp_vector = 0,
+ .comp_mask = IBV_CQ_INIT_ATTR_FLAGS,
+ .flags = IBV_CREATE_CQ_ATTR_COMPLETION_TIMESTAMP,
+ .wc_flags = IBV_WC_EX_WITH_COMPLETION_TIMESTAMP
+ };
+
+ ctx->cq = ibv_create_cq_ex(ctx->context, &attr_ex);
+ } else {
+ ctx->cq = ibv_create_cq(ctx->context, rx_depth + 1, NULL,
ctx->channel, 0);
+ }
+
if (!ctx->cq) {
fprintf(stderr, "Couldn't create CQ\n");
goto clean_mr;
@@ -561,6 +596,7 @@ static void usage(const char *argv0)
printf(" -e, --events sleep on CQ events (default poll)\n");
printf(" -g, --gid-idx=<gid index> local port gid index\n");
printf(" -o, --odp use on demand paging\n");
+ printf(" -t, --ts get CQE with timestamp\n");
}

int main(int argc, char *argv[])
@@ -586,6 +622,12 @@ int main(int argc, char *argv[])
int sl = 0;
int gidx = -1;
char gid[33];
+ unsigned int comp_recv_max_time_delta = 0;
+ unsigned int comp_recv_min_time_delta = 0xffffffff;
+ uint64_t comp_recv_total_time_delta = 0;
+ uint64_t comp_recv_prev_time = 0;
+ int last_comp_with_ts = 0;
+ unsigned int comp_with_time_iters = 0;

srand48(getpid() * time(NULL));

@@ -604,11 +646,12 @@ int main(int argc, char *argv[])
{ .name = "events", .has_arg = 0, .val = 'e' },
{ .name = "gid-idx", .has_arg = 1, .val = 'g' },
{ .name = "odp", .has_arg = 0, .val = 'o' },
+ { .name = "ts", .has_arg = 0, .val = 't' },
{ 0 }
};

- c = getopt_long(argc, argv, "p:d:i:s:m:r:n:l:eg:o",
- long_options, NULL);
+ c = getopt_long(argc, argv, "p:d:i:s:m:r:n:l:eg:ot",
+ long_options, NULL);

if (c == -1)
break;
@@ -669,6 +712,9 @@ int main(int argc, char *argv[])
case 'o':
use_odp = 1;
break;
+ case 't':
+ use_ts = 1;
+ break;

default:
usage(argv[0]);
@@ -812,10 +858,24 @@ int main(int argc, char *argv[])

{
struct ibv_wc wc[2];
+ struct {
+ struct ibv_wc_ex wc_ex;
+ uint64_t completion_timestamp;
+ } wc_with_ts[2];
+ struct ibv_poll_cq_ex_attr attr = {
+ .comp_mask = 0,
+ .max_entries = 2
+ };
+ enum ibv_wc_status status;
+ uint64_t wr_id;
int ne, i;

do {
- ne = ibv_poll_cq(ctx->cq, 2, wc);
+ if (use_ts)
+ ne = ibv_poll_cq_ex(ctx->cq, &wc_with_ts[0].wc_ex, &attr);
+ else
+ ne = ibv_poll_cq(ctx->cq, 2, wc);
+
if (ne < 0) {
fprintf(stderr, "poll CQ failed %d\n", ne);
return 1;
@@ -824,14 +884,22 @@ int main(int argc, char *argv[])
} while (!use_event && ne < 1);

for (i = 0; i < ne; ++i) {
- if (wc[i].status != IBV_WC_SUCCESS) {
+ if (use_ts) {
+ status = wc_with_ts[i].wc_ex.status;
+ wr_id = wc_with_ts[i].wc_ex.wr_id;
+ } else {
+ status = wc[i].status;
+ wr_id = wc[i].wr_id;
+ }
+
+ if (status != IBV_WC_SUCCESS) {
fprintf(stderr, "Failed status %s (%d) for wr_id %d\n",
- ibv_wc_status_str(wc[i].status),
- wc[i].status, (int) wc[i].wr_id);
+ ibv_wc_status_str(status),
+ status, (int)wr_id);
return 1;
}

- switch ((int) wc[i].wr_id) {
+ switch ((int)wr_id) {
case PINGPONG_SEND_WRID:
++scnt;
break;
@@ -848,15 +916,39 @@ int main(int argc, char *argv[])
}

++rcnt;
+ if (use_ts && (wc_with_ts[i].wc_ex.wc_flags &
+ IBV_WC_EX_WITH_COMPLETION_TIMESTAMP)) {
+ if (last_comp_with_ts) {
+ uint64_t delta;
+
+ /* checking whether the clock was wrapped around */
+ if (wc_with_ts[i].completion_timestamp >= comp_recv_prev_time)
+ delta = wc_with_ts[i].completion_timestamp - comp_recv_prev_time;
+ else
+ delta = ctx->completion_timestamp_mask - comp_recv_prev_time +
+ wc_with_ts[i].completion_timestamp + 1;
+
+ comp_recv_max_time_delta = max(comp_recv_max_time_delta, delta);
+ comp_recv_min_time_delta = min(comp_recv_min_time_delta, delta);
+ comp_recv_total_time_delta += delta;
+ comp_with_time_iters++;
+ }
+
+ comp_recv_prev_time = wc_with_ts[i].completion_timestamp;
+ last_comp_with_ts = 1;
+ } else {
+ last_comp_with_ts = 0;
+ }
+
break;

default:
fprintf(stderr, "Completion for unknown wr_id %d\n",
- (int) wc[i].wr_id);
+ (int)wr_id);
return 1;
}

- ctx->pending &= ~(int) wc[i].wr_id;
+ ctx->pending &= ~(int)wr_id;
if (scnt < iters && !ctx->pending) {
if (pp_post_send(ctx)) {
fprintf(stderr, "Couldn't post send\n");
@@ -883,6 +975,12 @@ int main(int argc, char *argv[])
bytes, usec / 1000000., bytes * 8. / usec);
printf("%d iters in %.2f seconds = %.2f usec/iter\n",
iters, usec / 1000000., usec / iters);
+
+ if (use_ts && comp_with_time_iters) {
+ printf("Max receive completion clock cycles = %u\n", comp_recv_max_time_delta);
+ printf("Min receive completion clock cycles = %u\n", comp_recv_min_time_delta);
+ printf("Average receive completion clock cycles = %f\n", (double)comp_recv_total_time_delta / comp_with_time_iters);
+ }
}

ibv_ack_cq_events(ctx->cq, num_cq_events);
--
1.8.3.1