Hi, During testing of the most recent version of this patch we've hit a kernel bug in alloc_vmap_area(): } 412 BUG_ON(first->va_start < addr); <- Bug triggers here 413 if (addr + cached_hole_size < first->va_start) 414 cached_hole_size = first->va_start - addr; 415 } This appears to be caused by a call from: [<c050f870>] ? kmem_cache_alloc_notrace+0xa0/0xb0 [<c0503695>] ? __get_vm_area_node+0xc5/0x1c0 [<c0458625>] ? walk_system_ram_range+0xa5/0x1c0 [<c050383e>] ? get_vm_area_caller+0x4e/0x60 [<f827328c>] ? intel_opregion_init+0xbc/0x510 [i915] [<c0430ce0>] ? __ioremap_caller+0x2b0/0x420 [<f827328c>] ? intel_opregion_init+0xbc/0x510 [i915] [<c0430f98>] ? ioremap_nocache+0x18/0x20 [<f827328c>] ? intel_opregion_init+0xbc/0x510 [i915] [<f827328c>] ? intel_opregion_init+0xbc/0x510 [i915] [<c04cdc7c>] ? delayed_slow_work_enqueue+0xcc/0xf0 [<f80f7c20>] ? drm_kms_helper_poll_init+0xc0/0x130 [drm_kms_helper] [<f8248ec7>] ? i915_driver_load+0x757/0x10c0 [i915] [<f82471b0>] ? i915_vga_set_decode+0x0/0x20 [i915] [<f81c5675>] ? drm_sysfs_device_add+0x75/0xa0 [drm] [<f81c33d7>] ? drm_get_dev+0x2b7/0x4c0 [drm] [<c05f6986>] ? pci_match_device+0x16/0xc0 [<c05f68ab>] ? local_pci_probe+0xb/0x10 [<c05f76b1>] ? pci_device_probe+0x61/0x80 [<c06a34f7>] ? driver_probe_device+0x87/0x290 etc. So I guess that there might be something odd about that ioremap. It triggers on every boot of the machine in question. It looks to me as if perhaps its found a cached entry which doesn't fit in some way, but I'm not certain of that yet, Steve. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>