Hi, We have a use case where we need to create a queue for each core running, i.e. we need to create as many sched-groups (each with one unique bit set in the thrmask) as we have cores in the system and then create as many queues and tie them to each sched-group. This way we can create queues from which events are certain to be scheduled on a single core only.
We use these "single core queues" to trigger e.g. control operations or functions that need to be run on each core. For this you would need as many sched-groups as you have cores + some additional more for whatever partitioning the application wants to do. Adding more sched-groups did not seem to impact performance, at least not when they were unused. I'm a bit worried about the case where you would have a large amount of cores running and use these "single-core queues" for internal management operations, thus meaning that events on them would be quite rare. Would the ODP scheduler (linux-generic at least) keep polling these queues for events all the time even if they are empty or is there some logic to only dequeue from queues that actually contain events? /carl From: EXT Bill Fischofer [mailto:[email protected]] Sent: Thursday, November 19, 2015 3:44 PM To: Wallen, Carl (Nokia - FI/Espoo) <[email protected]> Cc: LNG ODP Mailman List <[email protected]> Subject: Re: [lng-odp] [PATCH 1/1] linux-generic: config: increase ODP_CONFIG_SCHED_GRPS to 256 No problem with picking a "good" number, but curious as to what the use case is for this proposed increase. On Thu, Nov 19, 2015 at 5:58 AM, Carl Wallen <[email protected]> wrote: Increase the ODP_CONFIG_SCHED_GRPS define from 16 to 256 to support a larger number of scheduling groups by default. Signed-off-by: Carl Wallen <[email protected]> --- platform/linux-generic/include/odp/config.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/platform/linux-generic/include/odp/config.h b/platform/linux-generic/include/odp/config.h index ee23df3..da8856f 100644 --- a/platform/linux-generic/include/odp/config.h +++ b/platform/linux-generic/include/odp/config.h @@ -61,7 +61,7 @@ static inline int odp_config_sched_prios(void) /** * Number of scheduling groups */ -#define ODP_CONFIG_SCHED_GRPS 16 +#define ODP_CONFIG_SCHED_GRPS 256 static inline int odp_config_sched_grps(void) { return ODP_CONFIG_SCHED_GRPS; -- 2.1.4 _______________________________________________ lng-odp mailing list [email protected] https://lists.linaro.org/mailman/listinfo/lng-odp _______________________________________________ lng-odp mailing list [email protected] https://lists.linaro.org/mailman/listinfo/lng-odp
