From: "Morten Brørup" <mb@smartsharesystems.com>
To: "Mattias Rönnblom" <mattias.ronnblom@ericsson.com>,
"Sivaprasad Tummala" <sivaprasad.tummala@amd.com>,
jerinj@marvell.com
Cc: <dev@dpdk.org>
Subject: RE: [PATCH] eventdev: fix alignment padding
Date: Tue, 18 Apr 2023 16:07:21 +0200 [thread overview]
Message-ID: <98CBD80474FA8B44BF855DF32C47DC35D87890@smartserver.smartshare.dk> (raw)
In-Reply-To: <8f006152-7cb7-6fc8-22e6-5187d7611430@ericsson.com>
> From: Mattias Rönnblom [mailto:mattias.ronnblom@ericsson.com]
> Sent: Tuesday, 18 April 2023 14.31
>
> On 2023-04-18 12:45, Sivaprasad Tummala wrote:
> > fixed the padding required to align to cacheline size.
> >
>
> What's the point in having this structure cache-line aligned? False
> sharing is a non-issue, since this is more or less a read only struct.
>
> This is not so much a comment on your patch, but the __rte_cache_aligned
> attribute.
When the structure is cache aligned, an individual entry in the array does not unnecessarily cross a cache line border. With 16 pointers and aligned, it uses exactly two cache lines. If unaligned, it may span three cache lines.
>
> > Fixes: 54f17843a887 ("eventdev: add port maintenance API")
> > Cc: mattias.ronnblom@ericsson.com
> >
> > Signed-off-by: Sivaprasad Tummala <sivaprasad.tummala@amd.com>
> > ---
> > lib/eventdev/rte_eventdev_core.h | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/lib/eventdev/rte_eventdev_core.h
> b/lib/eventdev/rte_eventdev_core.h
> > index c328bdbc82..c27a52ccc0 100644
> > --- a/lib/eventdev/rte_eventdev_core.h
> > +++ b/lib/eventdev/rte_eventdev_core.h
> > @@ -65,7 +65,7 @@ struct rte_event_fp_ops {
> > /**< PMD Tx adapter enqueue same destination function. */
> > event_crypto_adapter_enqueue_t ca_enqueue;
> > /**< PMD Crypto adapter enqueue function. */
> > - uintptr_t reserved[6];
> > + uintptr_t reserved[5];
> > } __rte_cache_aligned;
> >
> > extern struct rte_event_fp_ops rte_event_fp_ops[RTE_EVENT_MAX_DEVS];
next prev parent reply other threads:[~2023-04-18 14:07 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-18 10:45 Sivaprasad Tummala
2023-04-18 11:06 ` Morten Brørup
2023-04-18 12:40 ` Mattias Rönnblom
2023-04-18 12:30 ` Mattias Rönnblom
2023-04-18 14:07 ` Morten Brørup [this message]
2023-04-18 15:16 ` Mattias Rönnblom
2023-04-19 6:38 ` Morten Brørup
2023-05-17 13:20 ` Jerin Jacob
2023-05-17 13:35 ` Morten Brørup
2023-05-23 15:15 ` Jerin Jacob
2023-08-02 16:19 ` Jerin Jacob
2023-08-08 10:24 ` Jerin Jacob
2023-08-08 10:25 ` 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=98CBD80474FA8B44BF855DF32C47DC35D87890@smartserver.smartshare.dk \
--to=mb@smartsharesystems.com \
--cc=dev@dpdk.org \
--cc=jerinj@marvell.com \
--cc=mattias.ronnblom@ericsson.com \
--cc=sivaprasad.tummala@amd.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).