On 04/05 21:27:37, Jerin Jacob wrote: > -----Original Message----- > > Date: Tue, 4 Apr 2017 13:47:52 -0500 > > From: Brian Brooks <brian.bro...@arm.com> > > To: lng-odp@lists.linaro.org > > Subject: [lng-odp] [API-NEXT PATCH v2 00/16] A scalable software scheduler > > X-Mailer: git-send-email 2.12.2 > > > > This work derives from Ola Liljedahl's prototype [1] which introduced a > > scalable scheduler design based on primarily lock-free algorithms and > > data structures designed to decrease contention. A thread searches > > through a data structure containing only queues that are both non-empty > > and allowed to be scheduled to that thread. Strict priority scheduling is > > respected, and (W)RR scheduling may be used within queues of the same > > priority. > > Lastly, pre-scheduling or stashing is not employed since it is optional > > functionality that can be implemented in the application. > > > > In addition to scalable ring buffers, the algorithm also uses unbounded > > concurrent queues. LL/SC and CAS variants exist in cases where absense of > > ABA problem cannot be proved, and also in cases where the compiler's atomic > > built-ins may not be lowered to the desired instruction(s). Finally, a > > version > > of the algorithm that uses locks is also provided. > > > > See platform/linux-generic/include/odp_config_internal.h for further build > > time configuration. > > > > Use --enable-schedule-scalable to conditionally compile this scheduler > > into the library. > > This is an interesting stuff. > > Do you have any performance/latency numbers in comparison to exiting scheduler > for completing say two stage(ORDERED->ATOMIC) or N stage pipeline on any > platform?
To give an idea, the avg latency reported by odp_sched_latency is down to half that of other schedulers (pre-scheduling/stashing disabled) on 4c A53, 16c A57, and 12c broadwell. We are still preparing numbers, and I think it's worth mentioning that they are subject to change as this patch series changes over time. I am not aware of an existing benchmark that involves switching between different queue types. Perhaps this is happening in an example app? > When we say scalable scheduler, What application/means used to quantify > scalablity?? > > Do you have any numbers in comparison to existing scheduler to show > magnitude of the scalablity on any platform?
