DPDK patches and discussions
 help / color / mirror / Atom feed
From: Bruce Richardson <bruce.richardson@intel.com>
To: dev@dpdk.org
Cc: Radha Mohan Chintakuntla <radhac@marvell.com>,
	Veerasenareddy Burru <vburru@marvell.com>,
	Gagandeep Singh <g.singh@nxp.com>,
	Nipun Gupta <nipun.gupta@nxp.com>,
	Chengwen Feng <fengchengwen@huawei.com>,
	Kevin Laatz <kevin.laatz@intel.com>,
	Conor Walsh <conor.walsh@intel.com>,
	Bruce Richardson <bruce.richardson@intel.com>
Subject: [PATCH] dmadev: clarify visibility of completed jobs
Date: Thu, 12 May 2022 16:11:22 +0100	[thread overview]
Message-ID: <20220512151122.20304-1-bruce.richardson@intel.com> (raw)

Clarify that once an operation has completed, the output of that
operation is visible to all cores.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
---

This follows on from the discussion on-list[1]. Owing to the lack
of replies stating that hardware doesn't guarantee this property, I'm
taking the optimistic view and assuming that this is generally supported
by the DMA drivers. If not, I can do a different patch for some
capability flags to indicate the presence or not of this visibility
guarantee.

[1] https://lore.kernel.org/all/YkwxFZUqOfnL9cJC@bricha3-MOBL.ger.corp.intel.com/
---
 lib/dmadev/rte_dmadev.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/dmadev/rte_dmadev.h b/lib/dmadev/rte_dmadev.h
index ad9e7a0975..a7081e633c 100644
--- a/lib/dmadev/rte_dmadev.h
+++ b/lib/dmadev/rte_dmadev.h
@@ -1001,6 +1001,8 @@ rte_dma_submit(int16_t dev_id, uint16_t vchan)
  * @b EXPERIMENTAL: this API may change without prior notice.
  *
  * Return the number of operations that have been successfully completed.
+ * Once an operation has been reported as completed, the results of that
+ * operation will be visible to all cores on the system.
  *
  * @param dev_id
  *   The identifier of the device.
@@ -1058,6 +1060,8 @@ rte_dma_completed(int16_t dev_id, uint16_t vchan, const uint16_t nb_cpls,
  *
  * Return the number of operations that have been completed, and the operations
  * result may succeed or fail.
+ * Once an operation has been reported as completed successfully, the results of that
+ * operation will be visible to all cores on the system.
  *
  * @param dev_id
  *   The identifier of the device.
-- 
2.34.1


             reply	other threads:[~2022-05-12 15:11 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-05-12 15:11 Bruce Richardson [this message]
2022-05-12 16:18 ` Morten Brørup
2022-06-05 23:17   ` Thomas Monjalon

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=20220512151122.20304-1-bruce.richardson@intel.com \
    --to=bruce.richardson@intel.com \
    --cc=conor.walsh@intel.com \
    --cc=dev@dpdk.org \
    --cc=fengchengwen@huawei.com \
    --cc=g.singh@nxp.com \
    --cc=kevin.laatz@intel.com \
    --cc=nipun.gupta@nxp.com \
    --cc=radhac@marvell.com \
    --cc=vburru@marvell.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).