| b97d3a9c | 09-Mar-2020 |
Mattias Rönnblom <[email protected]> |
event/dsw: add port busy cycles xstats
DSW keeps an internal port load estimate, used by the load balancing
mechanism. As a side effect, it keeps track of the total number of
busy cycles since start
event/dsw: add port busy cycles xstats
DSW keeps an internal port load estimate, used by the load balancing
mechanism. As a side effect, it keeps track of the total number of
busy cycles since startup. This metric is indirectly exposed in the
form of DSW xstats' "port_<n>_event_proc_latency", which is the total
number of busy cycles divided by the total number of events processed
on a particular port.
An external application can take (event_latency * dequeued) to go back
to busy_cycles. One reason for doing this is to measure the port's
load during a longer time period, without resorting to sampling
"port_<n>_load". However, as the number dequeued events grows, a
rounding error in event_latency renders the application-calculated
busy_cycles inaccurate.
Thus, it makes sense to directly expose the number of busy cycles as a
DSW xstats, even though it might seem redundant.
Signed-off-by: Mattias Rönnblom <[email protected]>
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| 65388325 | 09-Mar-2020 |
Mattias Rönnblom <[email protected]> |
event/dsw: remove redundant control ring poll
On dequeue, polling the control ring once is enough.
Fixes: f6257b22e767 ("event/dsw: add load balancing")
Cc: [email protected]
Suggested-by: Ola Lilje
event/dsw: remove redundant control ring poll
On dequeue, polling the control ring once is enough.
Fixes: f6257b22e767 ("event/dsw: add load balancing")
Cc: [email protected]
Suggested-by: Ola Liljedahl <[email protected]>
Signed-off-by: Mattias Rönnblom <[email protected]>
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| 570ac17b | 09-Mar-2020 |
Mattias Rönnblom <[email protected]> |
event/dsw: avoid migration waves in large systems
DSW limits the rate of migrations on a per-port basis. Hence, as the
number of cores grows, so does the total migration capacity.
In high core-coun
event/dsw: avoid migration waves in large systems
DSW limits the rate of migrations on a per-port basis. Hence, as the
number of cores grows, so does the total migration capacity.
In high core-count systems, this allows for a situation where flows
are migrated to a lightly loaded port which recently already received
a number of new flows (from other ports). The processing load
generated by these new flows may not yet be reflected in the lightly
loaded port's load estimate. The result is that the previously lightly
loaded port is now overloaded.
This patch adds a rough estimate of the size of the inbound migrations
to a particular port, which can be factored into the migration logic,
avoiding the above problem.
Signed-off-by: Mattias Rönnblom <[email protected]>
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| 1f2b99e8 | 09-Mar-2020 |
Mattias Rönnblom <[email protected]> |
event/dsw: improve migration mechanism
Allowing moving multiple flows in one migration transaction, to
rebalance load more quickly.
Introduce a threshold to avoid migrating flows between ports with
event/dsw: improve migration mechanism
Allowing moving multiple flows in one migration transaction, to
rebalance load more quickly.
Introduce a threshold to avoid migrating flows between ports with very
similar load.
Simplify logic for selecting which flow to migrate. The aim is now to
move flows in such a way that the receiving port is as lightly-loaded
as possible (after receiving the flow), while still migrating enough
flows from the source port to reduce its load. This is essentially how
legacy strategy work as well, but the code is more readable.
Signed-off-by: Mattias Rönnblom <[email protected]>
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| c4cf44b6 | 04-Apr-2020 |
Mattias Rönnblom <[email protected]> |
event/dsw: extend xstats
To allow visualization of migrations, track the number flow
immigrations in "port_<N>_immigrations". The "port_<N>_migrations"
retains legacy semantics, but is renamed "port
event/dsw: extend xstats
To allow visualization of migrations, track the number flow
immigrations in "port_<N>_immigrations". The "port_<N>_migrations"
retains legacy semantics, but is renamed "port_<N>_emigrations".
Expose the number of events currently undergoing processing
(i.e. pending releases) at a particular port.
Signed-off-by: Mattias Rönnblom <[email protected]>
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