DPDK patches and discussions
 help / color / mirror / Atom feed
From: "Morten Brørup" <mb@smartsharesystems.com>
To: "Olivier Matz" <olivier.matz@6wind.com>,
	"Andrew Rybchenko" <andrew.rybchenko@oktetlabs.ru>
Cc: <dev@dpdk.org>
Subject: [dpdk-dev] rte_mempool_create conflicting parameter advice
Date: Thu, 3 Jun 2021 21:01:36 +0200	[thread overview]
Message-ID: <98CBD80474FA8B44BF855DF32C47DC35C61819@smartserver.smartshare.dk> (raw)

Olivier, Andrew (Memory pool maintainers)

While reviewing documentation for the parameters to rte_mempool_create(), I noticed these two conflicting recommendations:

1. n (the number of elements in the pool) is advised to be a power of two minus one.
2. cache_size is advised to have "n modulo cache_size == 0".

E.g. n could be 0xFFFF, but then n modulo any value cannot be 0.


The cache_size parameter description tells what happens when not following the advice.

The n parameter description should also tell what happens when not following the advice.


Furthermore, the documentation for rte_pktmbuf_pool_create() and alike simply refer to the documentation for rte_mempool_create() regarding the cache_size parameter, although they copy the documentation regarding the n parameter. If the cache_size advice is important, it should be copied rather than simply referred to.


                 reply	other threads:[~2021-06-03 19:01 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

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=98CBD80474FA8B44BF855DF32C47DC35C61819@smartserver.smartshare.dk \
    --to=mb@smartsharesystems.com \
    --cc=andrew.rybchenko@oktetlabs.ru \
    --cc=dev@dpdk.org \
    --cc=olivier.matz@6wind.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).