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| author | Kevin Traynor <ktraynor@redhat.com> | 2023-01-18 16:23:56 +0000 |
|---|---|---|
| committer | Ilya Maximets <i.maximets@ovn.org> | 2023-01-23 17:23:28 +0100 |
| commit | 948767a18d5c2fb73baf85e62f52fd5da990d077 (patch) | |
| tree | ebbe8b023fd46d21cc3ddfe699317aa5ca5c221c /Documentation | |
| parent | f62629a55894546ff043e8a116c3c57aff73c285 (diff) | |
| download | openvswitch-948767a18d5c2fb73baf85e62f52fd5da990d077.tar.gz | |
dpif-netdev: Set PMD load based sleep start/inc to 1 us.
Now that the timer slack for the PMD threads is reduced we can also
reduce the start/increment for PMD load based sleeping to match it.
This will further reduce initial sleep times making it more resilient
to interfaces that might be sensitive to large sleep times.
Signed-off-by: Kevin Traynor <ktraynor@redhat.com>
Reviewed-by: David Marchand <david.marchand@redhat.com>
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/topics/dpdk/pmd.rst | 15 |
1 files changed, 6 insertions, 9 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. |