From: Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>
To: Konstantin Ananyev <konstantin.ananyev@huawei.com>,
"mb@smartsharesystems.com" <mb@smartsharesystems.com>,
"olivier.matz@6wind.com" <olivier.matz@6wind.com>,
"konstantin.v.ananyev@yandex.ru" <konstantin.v.ananyev@yandex.ru>
Cc: "dev@dpdk.org" <dev@dpdk.org>,
Ruifeng Wang <Ruifeng.Wang@arm.com>,
Kamalakshitha Aligeri <Kamalakshitha.Aligeri@arm.com>,
Wathsala Wathawana Vithanage <wathsala.vithanage@arm.com>,
nd <nd@arm.com>, nd <nd@arm.com>
Subject: RE: [PATCH 4/4] mempool: use lcore API to check if lcore ID is valid
Date: Fri, 10 Mar 2023 04:01:07 +0000 [thread overview]
Message-ID: <DBAPR08MB58141A79477BC4B98B8C1F8998BA9@DBAPR08MB5814.eurprd08.prod.outlook.com> (raw)
In-Reply-To: <871c50be83964a08b7c2122d1694c80d@huawei.com>
<snip>
>
>
>
> >
> > Use lcore API to check if the lcore ID is valid. The runtime check
> > does not add much value.
>
> From my perspective it adds a perfect value:
> Only threads with valid lcore id have their own default mempool cache.
The threads would call 'rte_lcore_id()' to return their lcore_id. This ensures the lcore_id is valid already. Why do we need to check it again in rte_mempool_default_cache? Why would a thread use an incorrect lcore_id?
>
> > Hence use assert to validate
> > the lcore ID.
>
> Wonder why?
> What's wrong for the thread to try to get default mempool cache?
What are the cases where a thread does not know that it is not an EAL thread and call rte_mempool_default_cache with a random lcore_id?
Since, this API is called in the data plane, it makes sense to remove any additional validations.
> That would change existing behavior and in general seems wrong to me.
Agree on the change in existing behavior. We can discuss this once we agree/disagree on the above.
> So I am strongly opposed.
>
> > Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> > Reviewed-by: Wathsala Vithanage <wathsala.vithanage@arm.com>
> > Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
> > ---
> > lib/mempool/rte_mempool.h | 5 ++---
> > 1 file changed, 2 insertions(+), 3 deletions(-)
> >
> > diff --git a/lib/mempool/rte_mempool.h b/lib/mempool/rte_mempool.h
> > index 009bd10215..00c5aa961b 100644
> > --- a/lib/mempool/rte_mempool.h
> > +++ b/lib/mempool/rte_mempool.h
> > @@ -1314,10 +1314,9 @@ rte_mempool_cache_free(struct
> rte_mempool_cache
> > *cache); static __rte_always_inline struct rte_mempool_cache *
> > rte_mempool_default_cache(struct rte_mempool *mp, unsigned lcore_id)
> > {
> > - if (mp->cache_size == 0)
> > - return NULL;
> > + RTE_ASSERT(rte_lcore_id_is_valid(lcore_id));
> >
> > - if (lcore_id >= RTE_MAX_LCORE)
> > + if (mp->cache_size == 0)
> > return NULL;
> >
> > rte_mempool_trace_default_cache(mp, lcore_id,
> > --
> > 2.25.1
> >
next prev parent reply other threads:[~2023-03-10 4:01 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-09 4:57 [PATCH 0/4] Small corrections in mempool Honnappa Nagarahalli
2023-03-09 4:57 ` [PATCH 1/4] mempool: clarify mempool cache flush API behavior Honnappa Nagarahalli
2023-06-07 10:03 ` Morten Brørup
2023-03-09 4:57 ` [PATCH 2/4] mempool: clarify comments for mempool cache implementation Honnappa Nagarahalli
2023-06-07 10:10 ` Morten Brørup
2023-03-09 4:57 ` [PATCH 3/4] eal: add API to check if lcore id is valid Honnappa Nagarahalli
2023-06-07 10:19 ` Morten Brørup
2023-06-07 15:05 ` Stephen Hemminger
2023-03-09 4:57 ` [PATCH 4/4] mempool: use lcore API to check if lcore ID " Honnappa Nagarahalli
2023-03-09 9:39 ` Konstantin Ananyev
2023-03-10 4:01 ` Honnappa Nagarahalli [this message]
2023-03-10 14:06 ` Konstantin Ananyev
2023-06-07 9:35 ` [PATCH 0/4] Small corrections in mempool 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=DBAPR08MB58141A79477BC4B98B8C1F8998BA9@DBAPR08MB5814.eurprd08.prod.outlook.com \
--to=honnappa.nagarahalli@arm.com \
--cc=Kamalakshitha.Aligeri@arm.com \
--cc=Ruifeng.Wang@arm.com \
--cc=dev@dpdk.org \
--cc=konstantin.ananyev@huawei.com \
--cc=konstantin.v.ananyev@yandex.ru \
--cc=mb@smartsharesystems.com \
--cc=nd@arm.com \
--cc=olivier.matz@6wind.com \
--cc=wathsala.vithanage@arm.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).