Subject: Re: LFS writes and network receive (too much splhigh?)
To: Jason Thorpe <email@example.com>
From: Thor Lancelot Simon <firstname.lastname@example.org>
Date: 10/22/2006 15:41:24
On Sun, Oct 22, 2006 at 12:33:28PM -0700, Jason Thorpe wrote:
> Why would LFS be at splhigh()? Have you confirmed that in the code
> paths in question?
You're right. It's splbio() everywhere. There were splhigh() calls
in there years ago, and when I saw this misbehavior, I assumed that
there still were.
> More likely, I think, is that your network interface and your RAID
> controller are sharing an IRQ, or that the RAID controller is
> consuming a lot of PCI bandwidth during these bursts of activity.
bge1 at pci2 dev 9 function 1: Broadcom BCM5704C Dual Gigabit Ethernet
bge1: interrupting at ioapic1 pin 1 (irq 15)
amr0 at pci3 dev 3 function 0: AMI RAID <MegaRAID SATA 150-4D>
amr0: interrupting at ioapic2 pin 0 (irq 11)
The controllers are on separate PCI-X buses (which are not bridged
to the same "primary" bus; they're on an AMD HT<->PCI-X tunnel).
60MB/sec is the most I've seen to the disk, anyway.
What do you think is going on?
Thor Lancelot Simon email@example.com
"We cannot usually in social life pursue a single value or a single moral
aim, untroubled by the need to compromise with others." - H.L.A. Hart