From: Patrick McHardy <kaber@trash.net>
To: Vasily Averin <vvs@sw.ru>
Cc: rusty@rustcorp.com.au, netfilter-devel@lists.netfilter.org,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Eric Dumazet <dada1@cosmosbay.com>,
Andrew Morton <akpm@linux-foundation.org>,
"David S. Miller" <davem@davemloft.net>,
devel@openvz.org
Subject: Re: [PATCH 2.6.21-rc6] [netfilter] early_drop imrovement
Date: Fri, 06 Apr 2007 17:08:28 +0200 [thread overview]
Message-ID: <4616626C.9020100@trash.net> (raw)
In-Reply-To: <4616203A.80203@sw.ru>
Vasily Averin wrote:
> No, I've not investigated this scenario. It looks like you are right and my
> patch can leads to a long delays.
>
> In my experiments I've decreased ip_conntrack_max lower than number of hash
> buckets and got the "table full, dropping packet" errors in logs. I've looked on
> the conntrack list and found a huge number of conntracks that can be freed.
> However my hash bucket was empty and therefore I even did not have any chances
> to free something. That's why I would like to check the other hash buckets too.
>
> Ok, let's limit the number of conntracks that can be checked inside
> early_drop(). What do you prefer: some round number (for example 100) or
> fraction of ip_conntrack_max (for example 1%)?
A (small) fraction sounds better. We could even consider keeping track
of the number of conntracks that can be evicted (not assured), so in a
DOS situation we could save unnecessary table scans. Not sure if its
worth the effort though.
Anyway, please base your patch on the net-2.6.22 tree, which doesn't
include ip_conntrack anymore.
WARNING: multiple messages have this Message-ID (diff)
From: Patrick McHardy <kaber@trash.net>
To: Vasily Averin <vvs@sw.ru>
Cc: Eric Dumazet <dada1@cosmosbay.com>,
"David S. Miller" <davem@davemloft.net>,
Andrew Morton <akpm@linux-foundation.org>,
netfilter-devel@lists.netfilter.org, rusty@rustcorp.com.au,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
devel@openvz.org
Subject: Re: [PATCH 2.6.21-rc6] [netfilter] early_drop imrovement
Date: Fri, 06 Apr 2007 17:08:28 +0200 [thread overview]
Message-ID: <4616626C.9020100@trash.net> (raw)
In-Reply-To: <4616203A.80203@sw.ru>
Vasily Averin wrote:
> No, I've not investigated this scenario. It looks like you are right and my
> patch can leads to a long delays.
>
> In my experiments I've decreased ip_conntrack_max lower than number of hash
> buckets and got the "table full, dropping packet" errors in logs. I've looked on
> the conntrack list and found a huge number of conntracks that can be freed.
> However my hash bucket was empty and therefore I even did not have any chances
> to free something. That's why I would like to check the other hash buckets too.
>
> Ok, let's limit the number of conntracks that can be checked inside
> early_drop(). What do you prefer: some round number (for example 100) or
> fraction of ip_conntrack_max (for example 1%)?
A (small) fraction sounds better. We could even consider keeping track
of the number of conntracks that can be evicted (not assured), so in a
DOS situation we could save unnecessary table scans. Not sure if its
worth the effort though.
Anyway, please base your patch on the net-2.6.22 tree, which doesn't
include ip_conntrack anymore.
next prev parent reply other threads:[~2007-04-06 15:08 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-04-06 8:00 [PATCH 2.6.21-rc6] [netfilter] early_drop imrovement Vasily Averin
2007-04-06 8:24 ` Eric Dumazet
2007-04-06 10:26 ` Vasily Averin
2007-04-06 15:08 ` Patrick McHardy [this message]
2007-04-06 15:08 ` Patrick McHardy
2007-04-07 11:45 ` [PATCH nf-2.6.22] " Vasily Averin
2007-04-07 12:08 ` Eric Dumazet
2007-04-07 12:08 ` Eric Dumazet
2007-04-08 5:02 ` Vasily Averin
2007-05-09 6:59 ` [NETFILTER] early_drop() imrovement (v3) Vasily Averin
2007-06-25 13:53 ` Patrick McHardy
2007-06-25 14:36 ` Jan Engelhardt
2007-06-26 13:20 ` Vasily Averin
2007-06-26 13:27 ` Patrick McHardy
2007-06-27 8:46 ` [NETFILTER] early_drop() imrovement (v4) Vasily Averin
2007-06-27 8:52 ` Patrick McHardy
2007-06-27 8:52 ` Patrick McHardy
2007-06-27 12:04 ` Patrick McHardy
2007-06-27 12:29 ` Vasily Averin
2007-06-27 12:51 ` Patrick McHardy
2007-06-27 13:02 ` Vasily Averin
2007-06-27 13:18 ` Patrick McHardy
2007-06-27 13:23 ` Patrick McHardy
2007-06-27 13:25 ` Vasily Averin
2007-06-27 13:28 ` Patrick McHardy
2007-06-27 13:35 ` Patrick McHardy
2007-06-27 13:54 ` Patrick McHardy
2007-07-02 19:56 ` Rusty Russell
2007-07-03 6:39 ` Martin Josefsson
2007-07-03 11:42 ` Patrick McHardy
-- strict thread matches above, loose matches on Subject: below --
2007-04-06 7:48 [PATCH 2.6.21-rc6] [netfilter] early_drop imrovement Vasily Averin
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=4616626C.9020100@trash.net \
--to=kaber@trash.net \
--cc=akpm@linux-foundation.org \
--cc=dada1@cosmosbay.com \
--cc=davem@davemloft.net \
--cc=devel@openvz.org \
--cc=linux-kernel@vger.kernel.org \
--cc=netfilter-devel@lists.netfilter.org \
--cc=rusty@rustcorp.com.au \
--cc=vvs@sw.ru \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.