Description of problem: Kernel panic on booting hp-dl585-02.rhts.boston.redhat.com. Version-Release number of selected component (if applicable): kernel-rt-2.6.24.4-46.el5rt How reproducible: Unknown Additional info: This has been seen before on HP systems. The error is when gart_iommu_hole_init() fails to allocate memory for the AGP aperture and has the following traceback: Cannot allocate aperture memory hole (ffff810100000000,65536K) Kernel panic - not syncing: Not enough memory for aperture Pid: 0, comm: swapper Not tainted 2.6.24.4-46.el5rt #1 Call Trace: [<ffffffff8103b33c>] panic+0xaf/0x169 [<ffffffff814b6a8f>] ? __alloc_bootmem_nopanic+0x31/0x5c [<ffffffff814affaa>] gart_iommu_hole_init+0x4b4/0x57f [<ffffffff8105c282>] ? rt_up+0x29/0x52 [<ffffffff8128bb9e>] ? _etext+0x0/0x3f92 [<ffffffff814aa400>] pci_iommu_alloc+0x9/0x1a [<ffffffff814b153f>] mem_init+0x24/0x16d [<ffffffff814a2aaa>] start_kernel+0x258/0x329 [<ffffffff814a2119>] _sinittext+0x119/0x120
test logs with backtraces: http://rhts.redhat.com/cgi-bin/rhts/test_log.cgi?id=2811732
Where are we on this bug? I've seen a couple of panics in RHTS with this system and I wonder if we have bad h/w or if we need to ask the lab guys to change a BIOS setting?
Looks like CONFIG_DMAR was the culprit. Fixed in -71
Clark, Looks like it is back in 2.6.24.7-75.el5rt :( http://rhts.redhat.com/cgi-bin/rhts/test_log.cgi?id=3785310 <snip> Your BIOS doesn't leave a aperture memory hole Please enable the IOMMU option in the BIOS setup This costs you 64 MB of RAM Cannot allocate aperture memory hole (ffff810100000000,65536K) Kernel panic - not syncing: Not enough memory for aperture Pid: 0, comm: swapper Not tainted 2.6.24.7-75.el5rt #1 Call Trace: [<ffffffff8103ca80>] panic+0xaf/0x160 [<ffffffff814b8aa7>] ? __alloc_bootmem_nopanic+0x31/0x5c [<ffffffff814b1ee0>] gart_iommu_hole_init+0x4b7/0x582 [<ffffffff8105fe60>] ? rt_up+0x29/0x52 [<ffffffff8128d621>] ? _etext+0x0/0x3fbf [<ffffffff814ac3a1>] pci_iommu_alloc+0x9/0x15 [<ffffffff814b3460>] mem_init+0x24/0x16d [<ffffffff814a4aa2>] start_kernel+0x258/0x329 [<ffffffff814a4119>] _sinittext+0x119/0x120 </snip>
bumping priority/severity and reassigning to rostedt
Tried modifying the allocation mechanism in arch/x86/kernel/aperture_64.c, from using __alloc_bootmem_nopanic() to __alloc_bootmem_low() and got the following panic message: Your BIOS doesn't leave a aperture memory hole Please enable the IOMMU option in the BIOS setup This costs you 64 MB of RAM low bootmem alloc of 67108864 bytes failed! Kernel panic - not syncing: Out of low memory Pid: 0, comm: swapper Not tainted 2.6.24.7-rt14 #4 Call Trace: [<ffffffff8103ca94>] panic+0xaf/0x160 [<ffffffff814b8829>] ? __alloc_bootmem_core+0x12c/0x2e5 [<ffffffff814b8a6d>] __alloc_bootmem_low+0x73/0x7c [<ffffffff814b1e52>] gart_iommu_hole_init+0x429/0x582 [<ffffffff8105fe74>] ? rt_up+0x29/0x52 [<ffffffff8128d631>] ? _etext+0x0/0x3fbf [<ffffffff814ac3a1>] pci_iommu_alloc+0x9/0x15 [<ffffffff814b3460>] mem_init+0x24/0x16d [<ffffffff814a4aa2>] start_kernel+0x258/0x329 [<ffffffff814a4119>] _sinittext+0x119/0x120 (full boot log attached)
Created attachment 313513 [details] boot log of kernel with aperture alloc changed to __alloc_bootmem_low
*** This bug has been marked as a duplicate of bug 466341 ***