diff options
| -rw-r--r-- | Documentation/topics/dpdk/pmd.rst | 15 | ||||
| -rw-r--r-- | lib/dpif-netdev.c | 3 | ||||
| -rw-r--r-- | tests/pmd.at | 6 | ||||
| -rw-r--r-- | vswitchd/vswitch.xml | 4 |
4 files changed, 10 insertions, 18 deletions
diff --git a/Documentation/topics/dpdk/pmd.rst b/Documentation/topics/dpdk/pmd.rst index 0c3bb717f..e70986d16 100644 --- a/Documentation/topics/dpdk/pmd.rst +++ b/Documentation/topics/dpdk/pmd.rst @@ -334,10 +334,7 @@ when there is no load or very-low load on all the Rx queues they poll. This can be enabled by setting the max requested sleep time (in microseconds) for a PMD thread:: - $ ovs-vsctl set open_vswitch . other_config:pmd-maxsleep=500 - -Non-zero values will be rounded up to the nearest 10 microseconds to avoid -requesting very small sleep times. + $ ovs-vsctl set open_vswitch . other_config:pmd-maxsleep=50 With a non-zero max value a PMD may request to sleep by an incrementing amount of time up to the maximum time. If at any point the threshold of at least half @@ -356,12 +353,12 @@ Sleep time statistics for 10 secs can be seen with:: $ ovs-appctl dpif-netdev/pmd-stats-clear \ && sleep 10 && ovs-appctl dpif-netdev/pmd-perf-show -Example output, showing that during the last 10 seconds, 76.8% of iterations -had a sleep of some length. The total amount of sleep time was 9.15 seconds and -the average sleep time per iteration was 46 microseconds:: +Example output, showing that during the last 10 seconds, 74.5% of iterations +had a sleep of some length. The total amount of sleep time was 9.06 seconds +and the average sleep time where a sleep was requested was 9 microseconds:: - - sleep iterations: 153994 ( 76.8 % of iterations) - Sleep time (us): 9159399 ( 59 us/iteration avg.) + - sleep iterations: 977037 ( 74.5 % of iterations) + Sleep time (us): 9068841 ( 9 us/iteration avg.) Any potential power saving from PMD load based sleeping is dependent on the system configuration (e.g. enabling processor C-states) and workloads. diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c index 4f06e3f4e..c9f7179c3 100644 --- a/lib/dpif-netdev.c +++ b/lib/dpif-netdev.c @@ -177,7 +177,7 @@ static struct odp_support dp_netdev_support = { /* Number of pkts Rx on an interface that will stop pmd thread sleeping. */ #define PMD_SLEEP_THRESH (NETDEV_MAX_BURST / 2) /* Time in uS to increment a pmd thread sleep time. */ -#define PMD_SLEEP_INC_US 10 +#define PMD_SLEEP_INC_US 1 struct dpcls { struct cmap_node node; /* Within dp_netdev_pmd_thread.classifiers */ @@ -4983,7 +4983,6 @@ dpif_netdev_set_config(struct dpif *dpif, const struct smap *other_config) set_pmd_auto_lb(dp, autolb_state, log_autolb); pmd_max_sleep = smap_get_ullong(other_config, "pmd-maxsleep", 0); - pmd_max_sleep = ROUND_UP(pmd_max_sleep, 10); pmd_max_sleep = MIN(PMD_RCU_QUIESCE_INTERVAL, pmd_max_sleep); atomic_read_relaxed(&dp->pmd_max_sleep, &cur_pmd_max_sleep); if (first_set_config || pmd_max_sleep != cur_pmd_max_sleep) { diff --git a/tests/pmd.at b/tests/pmd.at index e0f58f7a6..c707f762c 100644 --- a/tests/pmd.at +++ b/tests/pmd.at @@ -1266,7 +1266,7 @@ OVS_WAIT_UNTIL([tail ovs-vswitchd.log | grep "PMD load based sleeps are disabled dnl Check low value max sleep get_log_next_line_num AT_CHECK([ovs-vsctl set open_vswitch . other_config:pmd-maxsleep="1"]) -OVS_WAIT_UNTIL([tail -n +$LINENUM ovs-vswitchd.log | grep "PMD max sleep request is 10 usecs."]) +OVS_WAIT_UNTIL([tail -n +$LINENUM ovs-vswitchd.log | grep "PMD max sleep request is 1 usecs."]) OVS_WAIT_UNTIL([tail -n +$LINENUM ovs-vswitchd.log | grep "PMD load based sleeps are enabled."]) dnl Check high value max sleep @@ -1294,8 +1294,8 @@ OVS_WAIT_UNTIL([tail -n +$LINENUM ovs-vswitchd.log | grep "PMD max sleep request OVS_WAIT_UNTIL([tail -n +$LINENUM ovs-vswitchd.log | grep "PMD load based sleeps are enabled."]) dnl Check rounding get_log_next_line_num -AT_CHECK([ovs-vsctl set open_vswitch . other_config:pmd-maxsleep="491"]) -OVS_WAIT_UNTIL([tail -n +$LINENUM ovs-vswitchd.log | grep "PMD max sleep request is 500 usecs."]) +AT_CHECK([ovs-vsctl set open_vswitch . other_config:pmd-maxsleep="499"]) +OVS_WAIT_UNTIL([tail -n +$LINENUM ovs-vswitchd.log | grep "PMD max sleep request is 499 usecs."]) OVS_WAIT_UNTIL([tail -n +$LINENUM ovs-vswitchd.log | grep "PMD load based sleeps are enabled."]) OVS_VSWITCHD_STOP diff --git a/vswitchd/vswitch.xml b/vswitchd/vswitch.xml index 8c4acfb18..2b57fc0e3 100644 --- a/vswitchd/vswitch.xml +++ b/vswitchd/vswitch.xml @@ -807,10 +807,6 @@ Rx queues that it polls. </p> <p> - To avoid requesting very small sleeps (e.g. less than 10 us) the - value will be rounded up to the nearest 10 us. - </p> - <p> The maximum value is <code>10000 microseconds</code>. </p> </column> |