On 03/06/2013 06:58 AM, Tetsuo Handa wrote: > Borislav Petkov wrote: >> Ok, before we continue guessing stuff, Tetsuo, can you please explain >> how exactly you're triggering this. More specifically, we need .config, >> hypervisor version, I'm assuming kernel is 3.9-rc1, Linux is guest/host >> etc, etc. > > I'm using CentOS 6.3 x86_32 guest running on VMware Workstation 6.5.5 for > Windows XP x86_32 host and VMware Player 4.0.5 for Windows 7 x86_64 host. > > Kernel version is 3.9-rc1 x86_32. This bug can be triggered only when the > guest has little RAM such that /proc/meminfo reports that HighTotal == 0. > Config is at http://I-love.SAKURA.ne.jp/tmp/config-3.9-rc1-acpi . > > I don't know why but changing kernel config to CONFIG_ACPI=n > ( http://I-love.SAKURA.ne.jp/tmp/config-3.9-rc1-noacpi ) solves this bug. > Well, should I run bisection on ACPI code?
I was able to reproduce and got some better debugging out of this: [ 0.193170] __cpa_process_fault(c1673e90, e4afa000, 1) [ 0.208752] max_pfn_mapped: 150528 [ 0.218886] PAGE_OFFSET: c0000000 [ 0.228597] PAGE_OFFSET + (max_pfn_mapped << PAGE_SHIFT)): e4c00000 [ 0.247837] slow_virt_to_phys(e4afa000): 0 The pte looks to actually _be_ empty: [ 44.038145] slow_virt_to_phys() pte: 0000000000000000 level: 1 Not sure what's going on in the end, but it does appear this is another win for the new BUG_ON(). There really does look to be a real bug here. BTW, the BUG_ON() is proving to be woefully inadequate. We need some better diagnostic messages out of there, and probably a nice dump of the pagetable walk too. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
