Red Hat Bugzilla – Bug 48763
Kernel crash with no apparent reason
Last modified: 2007-04-18 12:34:39 EDT
From Bugzilla Helper: User-Agent: Mozilla/4.77 [en] (X11; U; Linux 2.4.2-2 i686) Description of problem: Random crashes, better freeze, of the machine ONLY with kernel 2.4.3-12 (all RH updates installed up to today). NO crashes with 2.4.2-2 ! Crashes happen mostly when X is running and other programs like Netscape, Mozilla, Staroffice, Emacs... Seems also that network activity and in particular DNS resolution helps to crash. But I got some crashes in runlevel 3 when checking password authentication -> no login at all. How reproducible: Sometimes Steps to Reproduce: 1. wait a little bit and do things.... 2. 3. Actual Results: first some processes gets in uninterruptable status (D), then some (X)windows freeze, most often the CPU/MEM usage applet in Gnome crashes, then ... lockup. Only way out is RESET. Nothing in logs except for lines like Jul 11 13:29:35 berenice sendmail[905]: rejecting connections on daemon MTA:load average: 14 but they do not appear always (load average goes way up to 20 o 30). Expected Results: work normally Additional info: Machine has 2 NIC eth0: 3Com PCI 3c905C Tornado at 0xdc00, 00:01:...., IRQ 10 eth1: D-Link DFE-538TX (RealTek RTL8139) at 0xc88a5000, 00:50:...., IRQ 11 and 2 disks in software RAID1 hda: FUJITSU MPF3204AT, ATA DISK drive hdc: _NEC NR-7500A, ATAPI CD/DVD-ROM drive hdd: FUJITSU MPF3204AT, ATA DISK drive other info: CPU: Intel Pentium III (Coppermine) Detected 799.549 MHz processor Memory: 126216k/131072k available I am back running with kernel 2.4.2-2 and everything seems to be ok, as it has always been Thanks for any help, Andrea.
One+1/2 month later I got not a single comment about this one. Have no time right now to dig in kernel source or try kernel 2.4.9 or similar. kernel 2.4.2-2 working fine with me at the moment but I will need to upgrade soon... My comment is that out of a few tests it seems that the problem has to do with swapping. Once the box starts swapping a little bit, something goes wrong and cannot recover. Actually it can run for a little time still, but then all of a sudden it freezes. Could be that it is an already known bug of this kernel, no time to check right now. Sorry folks. Andrea (RHCE, Cisco CCDA etc.)
This is not known behavior. We do know that this kernel needs more swapspace than ram, and the releasenotes and the installer mention this; the installer even makes a swapfile to fix this. Kernel 2.4.7-2 (in rawhide) has the swap>ram problem fixed, and is otherwise very stable. (It has survived 2 public betatests without serious crasher bugs in core code)
No problem with swap, 128MB RAM and 512MB swap (waiting for upgrade to 256MB RAM). I'll try as soon as I will have time the new kernel (is it safe to put the rpms of the 2.4.7-2 from rawhide directly in a 7.1 installation? the machine is running some company's important jobs, cannot be down for more than a couple of hours). Anyway, my tests show that it is something relating to swapping in my opinion. What I did is to run 50 short processes at the same time, if the machine started with empty swap and RAM used 50%, I got the machine to 90% of RAM, average load 5 or 6 (as reported by xosview for example) and no big slow down in usual activities (just a few seconds more to open a ssh connection at the same time as the 50 processes). Same behaviour with kernel 2.4.2-2 and 2.4.3-12 The 50 processes concluded in about 1 minute. Starting instead with full RAM (runlevel 5 and open netscape and something else is enough) and approx 30MB swap used but nothing else running. Now with kernel 2.4.2-2 machine s lows down quite a bit (at moments the mouse and keyboard are dead), disks run madly, swap increases by 50MB (total used swap approx 80MB of 512MB), average load goes up to approx 50, but after 6 or 7 minutes the processes are finished and the machine (SWAP included) go back to the previous state. Same tests with kernel 2.4.3-12 I get a freeze as soon as the processes kick in and the swap and load average start to grow. Decreasing the number of processes to 15, kernel 2.4.2-2 runs with no problem, kernel 2.4.3-12 slows down a lot, and sometimes freezes other times manages to get to the end of the jobs but it is quite unstable and at any moment after that can freeze. In my tests it has survived at most 10 minutes, no more. My tests have been a little bit brutal but not too far from the actual use of the machine, in the sense that I have 50 processes starting all at the same time, and soon I will have 100. Last comment is that I have 2 disk in software RAID1, swap included. Anyway the machine run the same programs etc. with RedHat 6.2 and 7.0 and never had a problem, crash or anything. Andrea
Just installed 2.4.9-6-i686, no problems at all. The problem is ONLY with kernel 2.4.3-12. Thus, if you agree, we can close this totally useless bug report. Andrea
I'm glad 2.4.9-6 has it fixed; we did a lot of work getting the VM in better shape.