On Sat, Oct 21, 2017 at 08:54:46PM +0000, Matan Azrad wrote:
> Fail-safe attempts to read an ultimate statistics on removal time; if
> that fails, it uses the latest recorded snapshot.
>
> This patch adds timestamp for each stats snapshot to allow a time report
> since the last snapshot in case of the above failure.
>
> By this way, the user can estimate the stats read accuracy.
>
> Signed-off-by: Matan Azrad <ma...@mellanox.com>
Acked-by: Gaetan Rivet <gaetan.ri...@6wind.com>
> ---
> drivers/net/failsafe/failsafe_ether.c | 17 ++++++++++++-----
> drivers/net/failsafe/failsafe_ops.c | 10 ++++++++--
> drivers/net/failsafe/failsafe_private.h | 7 ++++++-
> 3 files changed, 26 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/net/failsafe/failsafe_ether.c
> b/drivers/net/failsafe/failsafe_ether.c
> index 0282891..6cb435f 100644
> --- a/drivers/net/failsafe/failsafe_ether.c
> +++ b/drivers/net/failsafe/failsafe_ether.c
> @@ -35,6 +35,7 @@
>
> #include <rte_flow.h>
> #include <rte_flow_driver.h>
> +#include <rte_cycles.h>
>
> #include "failsafe_private.h"
>
> @@ -317,12 +318,18 @@
>
> /* Attempt to read current stats. */
> err = rte_eth_stats_get(PORT_ID(sdev), &stats);
> - if (err)
> - WARN("Could not access latest statistics from sub-device %d,"
> - " using latest snapshot.\n", SUB_ID(sdev));
> + if (err) {
> + uint64_t timestamp = sdev->stats_snapshot.timestamp;
> +
> + WARN("Could not access latest statistics from sub-device %d.\n",
> + SUB_ID(sdev));
> + if (timestamp != 0)
> + WARN("Using latest snapshot taken before %lu
> seconds.\n",
> + (rte_rdtsc() - timestamp) / rte_get_tsc_hz());
> + }
> failsafe_stats_increment(&PRIV(sdev->fs_dev)->stats_accumulator,
> - err ? &sdev->stats_snapshot : &stats);
> - memset(&sdev->stats_snapshot, 0, sizeof(struct rte_eth_stats));
> + err ? &sdev->stats_snapshot.stats : &stats);
> + memset(&sdev->stats_snapshot, 0, sizeof(sdev->stats_snapshot));
> }
>
> static inline int
> diff --git a/drivers/net/failsafe/failsafe_ops.c
> b/drivers/net/failsafe/failsafe_ops.c
> index d360965..f460551 100644
> --- a/drivers/net/failsafe/failsafe_ops.c
> +++ b/drivers/net/failsafe/failsafe_ops.c
> @@ -38,6 +38,7 @@
> #include <rte_ethdev.h>
> #include <rte_malloc.h>
> #include <rte_flow.h>
> +#include <rte_cycles.h>
>
> #include "failsafe_private.h"
>
> @@ -592,13 +593,18 @@
>
> rte_memcpy(stats, &PRIV(dev)->stats_accumulator, sizeof(*stats));
> FOREACH_SUBDEV_STATE(sdev, i, dev, DEV_ACTIVE) {
> - ret = rte_eth_stats_get(PORT_ID(sdev), &sdev->stats_snapshot);
> + struct rte_eth_stats *snapshot = &sdev->stats_snapshot.stats;
> + uint64_t *timestamp = &sdev->stats_snapshot.timestamp;
> +
> + ret = rte_eth_stats_get(PORT_ID(sdev), snapshot);
> if (ret) {
> ERROR("Operation rte_eth_stats_get failed for
> sub_device %d with error %d",
> i, ret);
> + *timestamp = 0;
> return ret;
> }
> - failsafe_stats_increment(stats, &sdev->stats_snapshot);
> + *timestamp = rte_rdtsc();
> + failsafe_stats_increment(stats, snapshot);
> }
> return 0;
> }
> diff --git a/drivers/net/failsafe/failsafe_private.h
> b/drivers/net/failsafe/failsafe_private.h
> index d343ebf..d81cc3c 100644
> --- a/drivers/net/failsafe/failsafe_private.h
> +++ b/drivers/net/failsafe/failsafe_private.h
> @@ -93,6 +93,11 @@ enum dev_state {
> DEV_STARTED,
> };
>
> +struct fs_stats {
> + struct rte_eth_stats stats;
> + uint64_t timestamp;
> +};
> +
> struct sub_device {
> /* Exhaustive DPDK device description */
> struct rte_devargs devargs;
> @@ -103,7 +108,7 @@ struct sub_device {
> /* Device state machine */
> enum dev_state state;
> /* Last stats snapshot passed to user */
> - struct rte_eth_stats stats_snapshot;
> + struct fs_stats stats_snapshot;
> /* Some device are defined as a command line */
> char *cmdline;
> /* fail-safe device backreference */
> --
> 1.8.3.1
>
--
Gaëtan Rivet
6WIND
