Migrate from TBB Task API

Intel may decide to remove all task-related APIs from TBB, and already marked it as deprecated. The MR is what we could do to adapt to this change if Intel were to finalize the API decommissioning. The changes bring 1.5% improvement in scheduling overhead, as observed at 18 threads in ATLAS MC reconstruction scenario. Comments are very welcome.

Three components migrated to tbb::task_group are:

• AvalancheSchedulerSvc
• ThreadPoolSvc
• SerialTaskQueue

@clemenci We don't use SerialTaskQueue in ATLAS, nor do we use TBBMessageSvc. I don't know if these two components are used elsewhere. But I took the occasion to revise that code as well just to rewrite similar uses in one go. Please let me know if the components are obsolete.

The MR is based on !1051 (merged), so please do merge the latter first. Before then please find the changes here: eaac64db...99148103.

added code cleanup task scheduling labels

changed the description

mentioned in merge request !1068 (merged)

added 5 commits

• 87c50152 - migrate AvalancheSchedulerSvc to tbb::task_group to address deprecation of tbb::task API
• 317419c0 - migrate ThreadPoolSvc from tbb::task API to tbb::task_group
• 710b3b06 - add tbb::task_group::wait() to ensure emptiness and ~tbb::task_groups() noexcept-ness
• f994a6bf - Bugfixes in ThreadPoolSvc:
• 99148103 - migrate SerialTaskQueue from tbb::task to tbb::task_group API

Compare with previous version

changed the description

added 46 commits

• 99148103...c7d6fdfd - 41 commits from branch gaudi:master
• 56b9904a - migrate AvalancheSchedulerSvc to tbb::task_group to address deprecation of tbb::task API
• adc189db - migrate ThreadPoolSvc from tbb::task API to tbb::task_group
• b7d14e54 - add tbb::task_group::wait() to ensure emptiness and ~tbb::task_groups() noexcept-ness
• 4f837e56 - Bugfixes in ThreadPoolSvc:
• 21fb4450 - migrate SerialTaskQueue from tbb::task to tbb::task_group API

Compare with previous version

mentioned in issue #132 (closed)

added 225 commits

• 21fb4450...694dcf84 - 220 commits from branch gaudi:master
• fb46e7ff - migrate AvalancheSchedulerSvc to tbb::task_group to address deprecation of tbb::task API
• 9d93b454 - migrate ThreadPoolSvc from tbb::task API to tbb::task_group
• 6f7b6a12 - add tbb::task_group::wait() to ensure emptiness and ~tbb::task_groups() noexcept-ness
• a7fb325d - Bugfixes in ThreadPoolSvc:
• 6bd1eb37 - migrate SerialTaskQueue from tbb::task to tbb::task_group API

Compare with previous version

changed the description

I've just started looking at the TBB migration stuff again, and I think this MR is important.

We've already learned from the CMS experience about migrating to task groups: https://indico.cern.ch/event/1005030/contributions/4220164/attachments/2191281/3703619/HSF%20Switch%20to%20task_group.pdf

The only question at this point is if a more fundamental refactoring of the scheduling would be appropriate. However, I'd still prioritise this task_group migration in the short term anyway.

mentioned in issue #173 (closed)

mentioned in merge request !1065 (closed)

mentioned in merge request !1193 (merged)

added 142 commits

• 6bd1eb37...e4424a93 - 138 commits from branch gaudi:master
• 9fdcf724 - migrate AvalancheSchedulerSvc to tbb::task_group to address deprecation of tbb::task API
• ec3ab20e - migrate ThreadPoolSvc from tbb::task API to tbb::task_group
• 4a23c6c0 - add tbb::task_group::wait() to ensure emptiness and ~tbb::task_groups() noexcept-ness
• ae49f632 - Bugfixes in ThreadPoolSvc:

Compare with previous version

marked this merge request as ready

changed the description

changed title from Migrate away from TBB Task API to Migrate from TBB Task API

changed milestone to %v36r0

assigned to @clemenci

added lhcb-gaudi-head label

• [2021-05-21 00:04] Validation started with lhcb-gaudi-head#2934
• [2021-05-21 01:07] Validation started with lhcb-run2-gaudi-head#131
• [2021-05-21 01:36] Validation started with lhcb-gaudi-head#2934

approved this merge request

merged

mentioned in commit 06d75cd6