From: "Van Haaren, Harry" <harry.van.haaren@intel.com>
To: "Eads, Gage" <gage.eads@intel.com>, "dev@dpdk.org" <dev@dpdk.org>
Cc: "jerin.jacob@caviumnetworks.com" <jerin.jacob@caviumnetworks.com>,
"hemant.agrawal@nxp.com" <hemant.agrawal@nxp.com>,
"Richardson, Bruce" <bruce.richardson@intel.com>,
"santosh.shukla@caviumnetworks.com"
<santosh.shukla@caviumnetworks.com>,
"nipun.gupta@nxp.com" <nipun.gupta@nxp.com>
Subject: Re: [dpdk-dev] [PATCH v4 1/2] eventdev: add device stop flush callback
Date: Fri, 23 Mar 2018 16:57:25 +0000 [thread overview]
Message-ID: <E923DB57A917B54B9182A2E928D00FA65E01640A@IRSMSX101.ger.corp.intel.com> (raw)
In-Reply-To: <1521555187-25710-1-git-send-email-gage.eads@intel.com>
> From: Eads, Gage
> Sent: Tuesday, March 20, 2018 2:13 PM
> To: dev@dpdk.org
> Cc: jerin.jacob@caviumnetworks.com; Van Haaren, Harry
> <harry.van.haaren@intel.com>; hemant.agrawal@nxp.com; Richardson, Bruce
> <bruce.richardson@intel.com>; santosh.shukla@caviumnetworks.com;
> nipun.gupta@nxp.com
> Subject: [PATCH v4 1/2] eventdev: add device stop flush callback
>
> When an event device is stopped, it drains all event queues. These events
> may contain pointers, so to prevent memory leaks eventdev now supports a
> user-provided flush callback that is called during the queue drain process.
> This callback is stored in process memory, so the callback must be
> registered by any process that may call rte_event_dev_stop().
>
> This commit also clarifies the behavior of rte_event_dev_stop().
>
> This follows this mailing list discussion:
> http://dpdk.org/ml/archives/dev/2018-January/087484.html
>
> Signed-off-by: Gage Eads <gage.eads@intel.com>
<snip most of the code - looks good!>
> /**
> - * Stop an event device. The device can be restarted with a call to
> - * rte_event_dev_start()
> + * Stop an event device.
> + *
> + * This function causes all queued events to be drained. While draining
> events
> + * out of the device, this function calls the user-provided flush callback
> + * (if one was registered) once per event.
> + *
> + * This function does not drain events from event ports; the application is
> + * responsible for flushing events from all ports before stopping the
> device.
Question about how an application is expected to correctly cleanup all the
events here. Note in particular the last part: "application is responsible
for flushing events from all ports **BEFORE** stopping the device".
Given the event device is still running, how can the application be sure it has
flushed all the events (from the dequeue side in particular)?
In order to drain all events from the ports, I was expecting the following:
// stop scheduling new events to worker cores
rte_event_dev_stop()
---> callback gets called for each event
// to dequeue events from each port, and app cleans them up?
FOR_EACH_PORT( rte_event_dev_dequeue(..., port_id, ...) )
I'd like to avoid the dequeue-each-port() approach in application, as it adds
extra burden to clean up correctly...
What if we say that dequeue() returns zero after stop() (leaving events possibly
in the port-dequeue side SW buffers), and these events which were about to
be dequeued by the worker core are also passed to the dev_stop_flush callback?
next prev parent reply other threads:[~2018-03-23 16:57 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-05 23:01 [dpdk-dev] [PATCH " Gage Eads
2018-03-05 23:01 ` [dpdk-dev] [PATCH 2/2] event/sw: support " Gage Eads
2018-03-08 23:10 ` [dpdk-dev] [PATCH v2 1/2] eventdev: add " Gage Eads
2018-03-08 23:10 ` [dpdk-dev] [PATCH v2 2/2] event/sw: support " Gage Eads
2018-03-12 6:25 ` [dpdk-dev] [PATCH v2 1/2] eventdev: add " Jerin Jacob
2018-03-12 14:30 ` Eads, Gage
2018-03-12 14:38 ` Jerin Jacob
2018-03-15 4:12 ` [dpdk-dev] [PATCH v3 " Gage Eads
2018-03-15 4:12 ` [dpdk-dev] [PATCH v3 2/2] event/sw: support " Gage Eads
2018-03-20 7:44 ` [dpdk-dev] [PATCH v3 1/2] eventdev: add " Jerin Jacob
2018-03-20 14:11 ` Eads, Gage
2018-03-20 14:13 ` [dpdk-dev] [PATCH v4 " Gage Eads
2018-03-20 14:13 ` [dpdk-dev] [PATCH v4 2/2] event/sw: support " Gage Eads
2018-03-23 17:05 ` Van Haaren, Harry
2018-03-26 22:01 ` Eads, Gage
2018-04-02 8:03 ` Jerin Jacob
2018-04-02 15:50 ` Eads, Gage
2018-04-02 17:08 ` Jerin Jacob
2018-03-23 16:57 ` Van Haaren, Harry [this message]
2018-03-26 21:59 ` [dpdk-dev] [PATCH v4 1/2] eventdev: add " Eads, Gage
2018-03-27 8:20 ` Van Haaren, Harry
2018-03-29 11:02 ` Van Haaren, Harry
2018-03-29 18:34 ` Jerin Jacob
2018-03-30 9:54 ` Liang, Ma
2018-04-02 8:01 ` Jerin Jacob
2018-04-02 18:03 ` [dpdk-dev] [PATCH v5] " Gage Eads
2018-04-03 1:26 ` Jerin Jacob
2018-04-03 1:31 ` Jerin Jacob
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=E923DB57A917B54B9182A2E928D00FA65E01640A@IRSMSX101.ger.corp.intel.com \
--to=harry.van.haaren@intel.com \
--cc=bruce.richardson@intel.com \
--cc=dev@dpdk.org \
--cc=gage.eads@intel.com \
--cc=hemant.agrawal@nxp.com \
--cc=jerin.jacob@caviumnetworks.com \
--cc=nipun.gupta@nxp.com \
--cc=santosh.shukla@caviumnetworks.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).