linux-wireless.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Ben Greear <greearb@candelatech.com>
To: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Herbert Xu <herbert@gondor.apana.org.au>,
	"linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>
Subject: Question on rhashtable in worst-case scenario.
Date: Mon, 28 Mar 2016 13:29:14 -0700	[thread overview]
Message-ID: <56F9941A.3080501@candelatech.com> (raw)

Hello!

I have a use case for mac80211 where I create multiple stations to
the same remote peer MAC address.

I'm seeing cases where the rhashtable logic is returning -16 (EBUSY)
on insert (see sta_info_hash_add).
This is with the 4.4.6+ (plus local patches) kernel, and it has the patch mentioned
here:

https://lkml.org/lkml/2015/12/3/307

If I understand the code properly, my use case is going to be worst-case scenario,
where all of my items in the hash have the same key (peer mac addr).

I have my own secondary hash to handle most of my hot-path lookups, but I still need
the main hash to at least function in a linear-search manner.

Any idea what I can do to get rid of the EBUSY return code problem, or how
to debug it further?

Thanks,
Ben

-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com


             reply	other threads:[~2016-03-28 20:29 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-03-28 20:29 Ben Greear [this message]
2016-03-29 16:16 ` Question on rhashtable in worst-case scenario Ben Greear
2016-03-30  9:14   ` Johannes Berg
2016-03-30 13:55     ` Herbert Xu
2016-03-30 14:03       ` Johannes Berg
2016-03-30 14:09         ` Herbert Xu
2016-03-30 16:38     ` David Miller
2016-03-30 16:52       ` Ben Greear
2016-03-31  7:46         ` Johannes Berg
2016-03-31  7:50           ` Herbert Xu
2016-03-31 15:29             ` Johannes Berg
2016-04-01  0:46               ` Herbert Xu
2016-04-01 18:17                 ` Ben Greear
2016-04-01 21:34                 ` Johannes Berg
2016-04-02  1:46                   ` Herbert Xu
2016-04-02 18:33                     ` Johannes Berg
2016-03-31 15:13           ` Ben Greear
2016-03-31 15:22             ` Johannes Berg

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=56F9941A.3080501@candelatech.com \
    --to=greearb@candelatech.com \
    --cc=herbert@gondor.apana.org.au \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-wireless@vger.kernel.org \
    /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).