Red Hat Bugzilla – Bug 175652
adding more memory makes the machine use 100% CPU
Last modified: 2007-11-30 17:11:19 EST
From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8b) Gecko/20050217 Description of problem: HW: Dell poweredge SC 1425. with 2GB RAM. Working correctly on FC4 latest updates. I added 2GB more, now when it boots, the x server takes 100% cpu. I tried the last 3 kernels with the same results. I made the same memory upgrade on a similar machine with FC3 and no problems. I booted up with Knoppix 4.0.2 and boots up OK. I removed the new memory and system came back to normal. Version-Release number of selected component (if applicable): kernel-2.6.14-1.1644_FC4, xorg-x11-6.8.2-37.FC4.49.2.i386.rpm How reproducible: Always Steps to Reproduce: 1. shut running system down. Install memory 2. boot up 3. ssh to machine, top shows 100% CPU used. 4. shut system down, remove memory 5. boot up. System back to normal. Repeat with different kernels, with same results. Actual Results: ssh is very slow and top shows 100% CPU used by X server. Expected Results: ssh to machine, top shows cpu idle. Additional info: server has a simple VGA server card by ATI with 16MB of memory (no special card, no special xorg.conf)
can you strace the X server process thats taking up all teh CPU and see what its doing ? It sounds like an X bug to me, but I'll stay on the Cc for a while to be sure, and bring in the X folks.
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 2974 root 25 0 0 0 0 R 99.9 0.0 203:05.59 X 12066 root 25 0 4372 1216 1048 S 7.9 0.1 0:12.04 prefdm 1909 root 12 -3 11936 628 468 S 2.0 0.0 0:00.23 auditd 2716 root 15 0 2140 764 668 S 2.0 0.0 0:11.15 hald-addon-hid- 1 root 16 0 1740 576 492 S 0.0 0.0 0:01.25 init [root@linux2 ~]# strace -p 2974 attach: ptrace(PTRACE_ATTACH, ...): Operation not permitted is there another way to strace the process ?
I installed the latest kernel from your ftp, with the same results execpt that I was able to attached to the process, but nothing comes out of it and I cannot break from it. Tasks: 134 total, 2 running, 132 sleeping, 0 stopped, 0 zombie Cpu(s): 0.1% us, 42.1% sy, 0.0% ni, 57.8% id, 0.0% wa, 0.0% hi, 0.0% si Mem: 4149108k total, 191452k used, 3957656k free, 12072k buffers Swap: 4194288k total, 0k used, 4194288k free, 85168k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 2976 root 25 0 37872 8456 2012 R 99.7 0.2 2:21.21 X [root@linux2 ~]# uname -a Linux linux2 2.6.14-1.1651_FC4smp #1 SMP Mon Dec 12 21:46:12 EST 2005 i686 i686 i386 GNU/Linux [root@linux2 ~]# strace -p 2976 Process 2976 attached - interrupt to quit Thanks,
Created attachment 122200 [details] Xstrace-output-linux2-4Gb-2.6.14-1.1651_FC4smp.txt ran strace twice on X
I power cycled and got the problem, then I just issued a 'reboot' and the machine came back up without the problem. The difference this time is that the machine was coming up from a power-on state instead of a power cycle. Note that knoppix was able to boot from a power cycle. I attached the strace output of X running without the problem. There seems to be a buffer overflow.
Since this bugzilla report was filed, there have been several major updates to the X Window System, which may resolve this issue. Users who have experienced this problem are encouraged to upgrade to the latest version of Fedora Core, which can be obtained from: http://fedora.redhat.com/download If this issue turns out to still be reproduceable in the latest version of Fedora Core, please file a bug report in the X.Org bugzilla located at http://bugs.freedesktop.org in the "xorg" component. Once you've filed your bug report to X.Org, if you paste the new bug URL here, Red Hat will continue to track the issue in the centralized X.Org bug tracker, and will review any bug fixes that become available for consideration in future updates. Setting status to "CURRENTRELEASE".