linux-gen: sched: configurable default burst size

Make default burst sizes configurable. User can set limits for
burst size round up in high/low priority. When less than
burst_size_xx events are requested, scheduler rounds up the
number of events to these limit and stash extra events. Requests
with more events are not round down. So, user can use small
values in burst size configure for better real-time support, but
still request large number of events for better throughput on
non real-time threads.

Signed-off-by: Petri Savolainen <petri.savolainen@linaro.org>
Reviewed-by: Bill Fischofer <bill.fischofer@linaro.org>
Signed-off-by: Maxim Uvarov <maxim.uvarov@linaro.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/config/odp-linux-generic.conf b/config/odp-linux-generic.conf
index f5f21b45f..85d5414ba 100644
--- a/config/odp-linux-generic.conf
+++ b/config/odp-linux-generic.conf
@@ -55,4 +55,15 @@ sched_basic: {
 	# uneven service level for low thread counts. Typically, optimal
 	# value is the number of threads using the scheduler.
 	prio_spread = 4
+
+	# Default burst sizes for high and low priority queues. The default
+	# and higher priority levels are considered as high. Scheduler
+	# rounds up number of requested events up to these values. In general,
+	# larger requests are not round down. So, larger bursts than these may
+	# received when requested. A large burst size improves throughput,
+	# but decreases application responsiveness to high priority events
+	# due to head of line blocking cause by a burst of low priority
+	# events.
+	burst_size_hi  = 32
+	burst_size_low = 16
 }