From: Patrick McHardy <kaber@trash.net>
To: David Laight <David.Laight@ACULAB.COM>
Cc: 'Eric Dumazet' <eric.dumazet@gmail.com>,
Alexei Starovoitov <alexei.starovoitov@gmail.com>,
Daniel Borkmann <daniel@iogearbox.net>,
"davem@davemloft.net" <davem@davemloft.net>,
"tgraf@suug.ch" <tgraf@suug.ch>,
"pablo@netfilter.org" <pablo@netfilter.org>,
"johunt@akamai.com" <johunt@akamai.com>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>
Subject: Re: [PATCH net] rhashtable: use cond_resched()
Date: Thu, 26 Feb 2015 15:46:44 +0000 [thread overview]
Message-ID: <20150226154643.GA18965@acer.localdomain> (raw)
In-Reply-To: <063D6719AE5E284EB5DD2968C1650D6D1CAEEE09@AcuExch.aculab.com>
On 26.02, David Laight wrote:
> From: Eric Dumazet
> Sent: 26 February 2015 15:21
> > If a hash table has 128 slots and 16384 elems, expand to 256 slots
> > takes more than one second. For larger sets, a soft lockup is detected.
>
> What on earth is it doing?
> Presumably something to do with the rcu actions needed to allow
> lockless lookup during resize.
>
> There has to be a better solution?
> Perhaps even two sets of chain pointers down the hash lists.
> Then the old hash table can be kept completely valid while the
> whole 'unzip' action is done.
One of the main points of rhashtable is that you don't need those.
next prev parent reply other threads:[~2015-02-26 15:46 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-25 22:09 [PATCH net 2/2] rhashtable: remove indirection for grow/shrink decision functions Alexei Starovoitov
2015-02-26 7:53 ` Patrick McHardy
2015-02-26 8:54 ` Daniel Borkmann
2015-02-26 14:50 ` Eric Dumazet
2015-02-26 14:54 ` Patrick McHardy
2015-02-26 15:20 ` [PATCH net] rhashtable: use cond_resched() Eric Dumazet
2015-02-26 15:36 ` David Laight
2015-02-26 15:46 ` Patrick McHardy [this message]
2015-02-26 16:03 ` David Laight
2015-02-26 15:50 ` Daniel Borkmann
2015-02-27 22:55 ` David Miller
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=20150226154643.GA18965@acer.localdomain \
--to=kaber@trash.net \
--cc=David.Laight@ACULAB.COM \
--cc=alexei.starovoitov@gmail.com \
--cc=daniel@iogearbox.net \
--cc=davem@davemloft.net \
--cc=eric.dumazet@gmail.com \
--cc=johunt@akamai.com \
--cc=netdev@vger.kernel.org \
--cc=pablo@netfilter.org \
--cc=tgraf@suug.ch \
/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