From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.2.1) Gecko/20021218

Description of problem:
Just switching tasks from gnome desktop yielded the following error:

Jan 12 20:47:39 f1j kernel: ------------[ cut here ]------------
Jan 12 20:47:39 f1j kernel: kernel BUG at page_alloc.c:131!
Jan 12 20:47:39 f1j kernel: invalid operand: 0000
Jan 12 20:47:39 f1j kernel: ide-cd cdrom radeon agpgart emu10k1 ac97_codec sound
soundcore autofs tg3 iptable_filter ip_tables loop lvm-mod keybdev mousedev hid
input usb-uhci ehci-hcd u
Jan 12 20:47:39 f1j kernel: CPU:    0
Jan 12 20:47:39 f1j kernel: EIP:    0060:[<c013c77b>]    Not tainted
Jan 12 20:47:39 f1j kernel: EFLAGS: 00013202
Jan 12 20:47:39 f1j kernel: 
Jan 12 20:47:39 f1j kernel: EIP is at __free_pages_ok [kernel] 0xeb (2.4.20-2.12)
Jan 12 20:47:39 f1j kernel: eax: 01000050   ebx: c18b1118   ecx: c1000030   edx:
27cdc008
Jan 12 20:47:39 f1j kernel: esi: 00000000   edi: 00000000   ebp: 00000000   esp:
ed3c5e18
Jan 12 20:47:39 f1j kernel: ds: 0068   es: 0068   ss: 0068
Jan 12 20:47:39 f1j kernel: Process X (pid: 1031, stackpage=ed3c5000)
Jan 12 20:47:39 f1j kernel: Stack: c03097e0 00000002 c0309a44 c187b648 ea162e20
e94ae64c 00100000 c0130c60 
Jan 12 20:47:39 f1j su(pam_unix)[1360]: session closed for user root
Jan 12 20:47:39 f1j kernel:        ea162d78 00000004 000a7000 e94ae650 00100000
27bbb067 c012f310 c18b1118 
Jan 12 20:47:39 f1j kernel:        ed3c5e6c c0119423 c2e6f1dc 000000a8 08c00000
ed3c608c 089ed000 00000000 
Jan 12 20:47:39 f1j kernel: Call Trace:   [<c0130c60>] set_page_dirty [kernel]
0x60 (0xed3c5e34))
Jan 12 20:47:39 f1j kernel: [<c012f310>] zap_pte_range [kernel] 0x110 (0xed3c5e50))
Jan 12 20:47:39 f1j kernel: [<c0119423>] sys_sched_yield [kernel] 0x73 (0xed3c5e5c))
Jan 12 20:47:39 f1j kernel: [<c012d62b>] zap_page_range [kernel] 0xbb (0xed3c5e78))
Jan 12 20:47:39 f1j kernel: [<c01308ef>] exit_mmap [kernel] 0xbf (0xed3c5eb4))
Jan 12 20:47:39 f1j kernel: [<c0119e6a>] mmput [kernel] 0x4a (0xed3c5ed8))
Jan 12 20:47:39 f1j kernel: [<c011f379>] do_exit [kernel] 0xf9 (0xed3c5ee8))
Jan 12 20:47:39 f1j kernel: [<c0125ecc>] sig_exit [kernel] 0x4c (0xed3c5f04))
Jan 12 20:47:39 f1j kernel: [<c0109424>] do_signal [kernel] 0x1b4 (0xed3c5f14))
Jan 12 20:47:39 f1j kernel: [<c0127591>] sys_tkill [kernel] 0x81 (0xed3c5f28))
Jan 12 20:47:39 f1j kernel: [<c0145b75>] fput [kernel] 0xd5 (0xed3c5f70))
Jan 12 20:47:39 f1j kernel: [<c0127148>] sys_rt_sigprocmask [kernel] 0xc8
(0xed3c5f84))
Jan 12 20:47:39 f1j kernel: [<c0109760>] signal_return [kernel] 0x14 (0xed3c5fc0))
Jan 12 20:47:39 f1j kernel: 
Jan 12 20:47:39 f1j kernel: 
Jan 12 20:47:39 f1j kernel: Code: 0f 0b 83 00 d4 c9 25 c0 8b 43 18 89 f9 89 de
83 e0 eb 89 43 
Jan 12 20:47:39 f1j gdm(pam_unix)[1030]: session closed for user fxj
Jan 12 20:47:40 f1j gdm[1030]: gdm_slave_xioerror_handler: Fatal X error -
Restarting :0
Jan 12 20:47:41 f1j gdm[1547]: gdm_slave_xioerror_handler: Fatal X error -
Restarting :0
Jan 12 20:47:43 f1j gdm[1549]: gdm_slave_xioerror_handler: Fatal X error -
Restarting :0
Jan 12 20:47:48 f1j gdm[1551]: gdm_slave_xioerror_handler: Fatal X error -
Restarting :0
Jan 12 20:47:53 f1j gdm[1553]: gdm_slave_xioerror_handler: Fatal X error -
Restarting :0
Jan 12 20:47:53 f1j gdm[987]: deal_with_x_crashes: Running the XKeepsCrashing script

Version-Release number of selected component (if applicable):


How reproducible:
Sometimes

Steps to Reproduce:
1. Several non intensive apps running
2. Move mouse to next app

    

Actual Results:  Crash

Expected Results:  Other running app should become active window

Additional info: