kern/177536: [zfs] zfs livelock (deadlock) with high write-to-disk load

[Christopher D. Harrison]

The following reply was made to PR kern/177536; it has been noted by GNATS.

From: "Christopher D. Harrison" <harrison at biostat.wisc.edu>
To: bug-followup at FreeBSD.org, Martin.Birgmeier at aon.at
Cc:  
Subject: Re: kern/177536: [zfs] zfs livelock (deadlock) with high write-to-disk
 load
Date: Wed, 31 Jul 2013 11:36:26 -0500

 I have also been hitting this bug with 9.1-RELEASE.    My debugging has 
 got me to the point where I am almost certain the problem is in the MPS 
 driver in 9.1-RELEASE.   9.0-RELEASE would not deadlock under high I/O 
 but 9.1-RELEASE running the mps driver seems too.
 Martin:
 What device are your drives connected too?   Is it an LSI HBA?
 
 My device is:
 mps0 at pci0:5:0:0:    class=0x010700 card=0x30c01000 chip=0x00641000 
 rev=0x02 hdr=0x00
      vendor     = 'LSI Logic / Symbios Logic'
      device     = 'SAS2116 PCI-Express Fusion-MPT SAS-2 [Meteor]'
      class      = mass storage
      subclass   = SAS
 igb2 at pci0:4:0:0:    class=0x020000 card=0x10c915d9 chip=0x10c98086 
 rev=0x01 hdr=0x00
 
 I have 6 systems in production which experience this deadlock issue.   
 The deadlock appears most frequently under high load but I have 
 experienced it on systems which are idle too.
 
      -C