On Fri, Jun 7, 2024 at 7:17 PM Mattias Rönnblom <mattias.ronnb...@ericsson.com> wrote: > > Add the RTE_EVENT_DEV_CAP_IMPLICIT_RELEASE_DISABLE capability to the > DSW event device. > > This feature may be used by an EAL thread to pull more work from the > work scheduler, without giving up the option to forward events > originating from a previous dequeue batch. This in turn allows an EAL > thread to be productive while waiting for a hardware accelerator to > complete some operation. > > Prior to this change, DSW didn't make any distinction between > RTE_EVENT_OP_FORWARD and RTE_EVENT_OP_NEW type events, other than that > new events would be backpressured earlier. > > After this change, DSW tracks the number of released events (i.e., > events of type RTE_EVENT_OP_FORWARD and RTE_EVENT_OP_RELEASE) that has > been enqueued. > > For efficiency reasons, DSW does not track the identity of individual > events. This in turn implies that a certain stage in the flow > migration process, DSW must wait for all pending releases (on the > migration source port, only) to be received from the application, to > assure that no event pertaining to any of the to-be-migrated flows are > being processed. > > With this change, DSW starts making a distinction between forward and > new type events for credit allocation purposes. Only RTE_EVENT_OP_NEW > events needs credits. All events marked as RTE_EVENT_OP_FORWARD must > have a corresponding dequeued event from a previous dequeue batch. > > Flow migration for flows on RTE_SCHED_TYPE_PARALLEL queues remains > unaffected by this change. > > A side-effect of the tweaked DSW migration logic is that the migration > latency is reduced, regardless if implicit release is enabled or not. > > Another side-effect is that migrated flows are now not processed > during any part of the migration procedure. An upside of this change > it reduces the load of the overloaded port. A downside is it > introduces slightly more jitter for the migrated flows. > > This patch is contains various minor refactorings, improved > formatting, fixed spelling, and the removal of unnessary memory > barriers.
Move changelog after --- > > v3: > * Fix broken RTE_ASSERT()s. (Jerin Jacob) > > v2: > * Remove redundant memory barriers. > * Discontinue processing of migrated flows throughout the migration > procedure. This is a part of a fix to address a reordering issue > v1 of this patch introduced. > * Added entry in the release notes. > * Fix spelling issues in commit message. > > Signed-off-by: Mattias Rönnblom <mattias.ronnb...@ericsson.com> > --- > doc/guides/rel_notes/release_24_07.rst | 7 + > drivers/event/dsw/dsw_evdev.c | 8 +- > drivers/event/dsw/dsw_evdev.h | 7 +- > drivers/event/dsw/dsw_event.c | 405 ++++++++++++++----------- > 4 files changed, 254 insertions(+), 173 deletions(-) > > diff --git a/doc/guides/rel_notes/release_24_07.rst > b/doc/guides/rel_notes/release_24_07.rst > index a69f24cf99..706cc71212 100644 > --- a/doc/guides/rel_notes/release_24_07.rst > +++ b/doc/guides/rel_notes/release_24_07.rst > @@ -24,6 +24,13 @@ DPDK Release 24.07 > New Features > ------------ > > +* **Updated the DSW event device.** > + > + * Added support for ``RTE_EVENT_DEV_CAP_IMPLICIT_RELEASE_DISABLE``, > + allowing applications to take on new tasks without having completed > + (released) the previous event batch. This in turn facilities DSW > + use alongside high-latency look-aside hardware accelerators. > + > .. This section should contain new features added in this release. > Sample format: Update should be here(after the template). Fixed above issues and applied to dpdk-next-eventdev/for-main. Thanks
