Messages in this thread | | | From | "Gregory K. Ruiz-Ade" <> | Subject | 2.4.20 instability on bigmem systems? | Date | Thu, 13 Mar 2003 16:27:22 -0800 |
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This started out as my asking about random crashes on 2.4.19, but in the course of me trying to figure out what was going on, I got to experience first-hand the increadibly poor performance of 2.4.x (notably 2.4.20) on a system with >4GB of memory (8GB).
So, I'm looking for a solution, preferrably a set of patches, to help with the problems described below.
On Monday, I installed a 2.4.20 kernel on our Dell PowerEdge 6600. This machine is configured as follows:
4x 1.6Ghz Xeon CPUs 8GB RAM Built-in: ATI Rage 128 graphics dual Broadcomm Gigabit Ethernet serial/parallel/usb Adaptec SCSI Dell PERC3/DC (AMI/LSI MegaRAID) dual-channel
The kernel was built from the linux-2.4.20.tar.bz2 from kernel.org, and patched with only the lvm-1.0.7 and linux-2.4.20 VFS locking patches from Sistina's LVM-1.0.7 package.
The primary problem: Whenever any process (or set of processes) initiates intensive disk I/O, the system grinds to a halt, kswapd and kupdated consume upwards of 40% to 60% CPU each, and system load averages can jump upwards of 21.00. The problem can be replicated with a simple find command ("find / -print" seems to do it nicely).
I have had two rather painful nights dealing with this (Monday and Tuesday nights). Luckily, I have a serial null-modem cable rigged up between the troubled server and another server, and was able to capture all the info from the Magic Sysrq commands that I could.
Full details are at http://castandcrew.com/~gregory/lkmlstuff/burpr/2.4.20
I've included the kernel config, the kernel and initrd images, the system map file, output from "ps auxfww" and a couple screen scrapings from top, and captures from magic sysrq commands from both crashes.
I had problems like this with 2.4.19, and was directed to apply a patch to inode.c, which appears to be part of a patch set for 2.4.19pre9aa2. I've archived it at:
http://castandcrew.com/~gregory/lkmlstuff/burpr/2.4.19/patches/10_inode-highmem-2
For 2.4.19, this solves _most_ of the stability issues, but I still have to work with the LVM people and possibly whomever is responsible for the VM in 2.4.19/2.4.20 to track down some kernel oopses (possibly a seperate problem.)
I will happily provide whatever other information is needed, though my opportunities to test things on the machine in question is limited by the fact that it's a production server.
Thanks in advance, Gregory
-- Gregory K. Ruiz-Ade <gregory@castandcrew.com> Sr. Systems Administrator Cast & Crew Entertainment Services, Inc.
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