netdev - Re: Strange packet drops with heavy firewalling

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <m3633szw61.fsf@ursa.amorsen.dk>
Date:	Thu, 15 Apr 2010 15:23:50 +0200
From:	Benny Amorsen <benny+usenet@...rsen.dk>
To:	Eric Dumazet <eric.dumazet@...il.com>
Cc:	Changli Gao <xiaosuo@...il.com>,
	zhigang gong <zhigang.gong@...il.com>, netdev@...r.kernel.org
Subject: Re: Strange packet drops with heavy firewalling

Benny Amorsen <benny+usenet@...rsen.dk> writes:

> I'll keep monitoring the server, and if it starts dropping packets again
> or load increases I'll check whether irqbalanced does the right thing,
> and if not I'll implement your suggestion.

It did start dropping packets (although very few, a few packets dropped
at once perhaps every ten minutes). Irqbalanced didn't move the
interrupts.

Doing

echo 01 >/proc/irq/99/smp_affinity
echo 02 >/proc/irq/100/smp_affinity
echo 04 >/proc/irq/101/smp_affinity

and so on like Erik Dumazet suggested seems to have helped, but not
entirely solved the problem.

The problem now manifests itself this way in ethtool -S:
     rx_no_buffer_count: 270
     rx_queue_drop_packet_count: 270

I can't be sure that I'm not just getting hit by a 1Gbps traffic spike,
of course, but it is a bit strange that a machine which can do 200Mbps
at 92% idle can't handle subsecond peaks close to 1Gbps...

I wish ifstat could report errors so I could see what the traffic rate
was when the problem occurred...

/Benny
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html