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From: Jerin Jacob <jerinjacobk@gmail.com>
To: "Mattias Rönnblom" <mattias.ronnblom@ericsson.com>
Cc: "Jerin Jacob" <jerinj@marvell.com>,
	dev@dpdk.org, hofors@lysator.liu.se, bruce.richardson@intel.com,
	"Peter Nilsson J" <peter.j.nilsson@ericsson.com>,
	"Svante Järvstråt" <svante.jarvstrat@ericsson.com>,
	"Heng Wang" <heng.wang@ericsson.com>
Subject: Re: [PATCH v3] event/dsw: support explicit release only mode
Date: Sat, 8 Jun 2024 11:44:24 +0530	[thread overview]
Message-ID: <CALBAE1O9oxncOL_6vDYj8kXTy-LwA=P6K8DTTqBHc9KUhm3igw@mail.gmail.com> (raw)
In-Reply-To: <20240607133615.374993-1-mattias.ronnblom@ericsson.com>

On Fri, Jun 7, 2024 at 7:17 PM Mattias Rönnblom
<mattias.ronnblom@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.ronnblom@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

  reply	other threads:[~2024-06-08  6:14 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-11-09 18:33 [RFC] " Mattias Rönnblom
2024-05-24 19:24 ` [PATCH] " Mattias Rönnblom
2024-05-27 15:35   ` Jerin Jacob
2024-05-27 16:08     ` Mattias Rönnblom
2024-05-27 17:17       ` Jerin Jacob
2024-06-05 13:38   ` [PATCH v2] " Mattias Rönnblom
2024-06-06  9:59     ` Jerin Jacob
2024-06-07 13:36     ` [PATCH v3] " Mattias Rönnblom
2024-06-08  6:14       ` Jerin Jacob [this message]
2024-06-08 16:02         ` Mattias Rönnblom

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