On 2015/4/1 17:17, Dave Young wrote: > On 04/01/15 at 04:34pm, Xishi Qiu wrote: >> On 2015/4/1 16:21, Xishi Qiu wrote: >> >>> On 2015/4/1 15:41, Dave Young wrote: >>> >>>> On 04/01/15 at 03:27pm, Xishi Qiu wrote: >>>>> On 2015/4/1 13:11, Dave Young wrote: >>>>> >>>>>> Ccing Xishi Qiu who wrote the clear_kernel_node_hotplug code. >>>>>> >>>>>> On 04/01/15 at 12:53pm, Dave Young wrote: >>>>>>> I got below kernel panic during kdump test on Thinkpad T420 laptop: >>>>>>> >>>>>>> [ 0.000000] No NUMA configuration found >>>>>>> >>>>>>> [ 0.000000] Faking a node at [mem >>>>>>> 0x0000000000000000-0x0000000037ba4fff] >>>>>>> [ 0.000000] Kernel panic - not syncing: stack-protector: Kernel >>>>>>> stack is cor >>>>>>> upted in: ffffffff81d21910 >>>>>>> r >>>>>>> [ 0.000000] >>>>>>> >>>>>>> [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.0.0-rc6+ #44 >>>>>>> >>>>>>> [ 0.000000] Hardware name: LENOVO 4236NUC/4236NUC, BIOS 83ET76WW >>>>>>> (1.46 ) 07/ >>>>>>> 5/2013 >>>>>>> 0 >>>>>>> [ 0.000000] 0000000000000000 c70296ddd809e4f6 ffffffff81b67ce8 >>>>>>> ffffffff817c >>>>>>> a26 >>>>>>> 2 >>>>>>> [ 0.000000] 0000000000000000 ffffffff81a61c90 ffffffff81b67d68 >>>>>>> ffffffff817b >>>>>>> 8d2 >>>>>>> c >>>>>>> [ 0.000000] 0000000000000010 ffffffff81b67d78 ffffffff81b67d18 >>>>>>> c70296ddd809 >>>>>>> 4f6 >>>>>>> e >>>>>>> [ 0.000000] Call Trace: >>>>>>> >>>>>>> [ 0.000000] [<ffffffff817c2a26>] dump_stack+0x45/0x57 >>>>>>> >>>>>>> [ 0.000000] [<ffffffff817bc8d2>] panic+0xd0/0x204 >>>>>>> >>>>>>> [ 0.000000] [<ffffffff81d21910>] ? >>>>>>> numa_clear_kernel_node_hotplug+0xe6/0xf2 >>>>>>> [ 0.000000] [<ffffffff8107741b>] __stack_chk_fail+0x1b/0x20 >>>>>>> >>>>>>> [ 0.000000] [<ffffffff81d21910>] >>>>>>> numa_clear_kernel_node_hotplug+0xe6/0xf2 >>>>>>> [ 0.000000] [<ffffffff81d21e5d>] numa_init+0x1a5/0x520 >>>>>>> >>>>>>> [ 0.000000] [<ffffffff81d222b1>] x86_numa_init+0x19/0x3d >>>>>>> >>>>>>> [ 0.000000] [<ffffffff81d22460>] initmem_init+0x9/0xb >>>>>>> >>>>>>> [ 0.000000] [<ffffffff81d0d00c>] setup_arch+0x94f/0xc82 >>>>>>> >>>>>>> [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120 >>>>>>> >>>>>>> [ 0.000000] [<ffffffff817bd0bb>] ? printk+0x55/0x6b >>>>>>> >>>>>>> [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120 >>>>>>> >>>>>>> [ 0.000000] [<ffffffff81d05d9b>] start_kernel+0xe8/0x4d6 >>>>>>> >>>>>>> [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120 >>>>>>> >>>>>>> [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120 >>>>>>> >>>>>>> [ 0.000000] [<ffffffff81d055ee>] >>>>>>> x86_64_start_reservations+0x2a/0x2c >>>>>>> [ 0.000000] [<ffffffff81d05751>] x86_64_start_kernel+0x161/0x184 >>>>>>> >>>>>>> [ 0.000000] ---[ end Kernel panic - not syncing: stack-protector: >>>>>>> Kernel sta >>>>>>> k is corrupted in: ffffffff81d21910 >>>>>>> c >>>>>>> [ 0.000000] >>>>>>> >>>>>>> PANIC: early exception 0d rip 10:ffffffff8105d2a6 error 7eb cr2 >>>>>>> ffff8800371dd00 >>>>>>> [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.0.0-rc6+ #44 >>>>>>> 0 >>>>>>> [ 0.000000] Hardware name: LENOVO 4236NUC/4236NUC, BIOS 83ET76WW >>>>>>> (1.46 ) 07/ >>>>>>> 5/2013 >>>>>>> 0 >>>>>>> [ 0.000000] 0000000000000000 c70296ddd809e4f6 ffffffff81b67c60 >>>>>>> ffffffff817c >>>>>>> a26 >>>>>>> 2 >>>>>>> [ 0.000000] 0000000000000096 ffffffff81a61c90 ffffffff81b67d68 >>>>>>> fffffff00000 >>>>>>> 084 0000000000000a0d 0000000000000a00 >>>>>>> 0 >>>>>>> [ 0.000000] Call Trace: >>>>>>> >>>>>>> [ 0.000000] [<ffffffff817c2a26>] dump_stack+0x45/0x57 >>>>>>> >>>>>>> [ 0.000000] [<ffffffff81d051b0>] early_idt_handler+0x90/0xb7 >>>>>>> >>>>>>> [ 0.000000] [<ffffffff8105d2a6>] ? native_irq_enable+0x6/0x10 >>>>>>> >>>>>>> [ 0.000000] [<ffffffff817bc9c5>] ? panic+0x1c3/0x204 >>>>>>> >>>>>>> [ 0.000000] [<ffffffff81d21910>] ? >>>>>>> numa_clear_kernel_node_hotplug+0xe6/0xf2 >>>>>>> [ 0.000000] [<ffffffff8107741b>] __stack_chk_fail+0x1b/0x20 >>>>>>> >>>>>>> [ 0.000000] [<ffffffff81d21910>] >>>>>>> numa_clear_kernel_node_hotplug+0xe6/0xf2 >>>>>>> [ 0.000000] [<ffffffff81d21e5d>] numa_init+0x1a5/0x520 >>>>>>> >>>>>>> [ 0.000000] [<ffffffff81d222b1>] x86_numa_init+0x19/0x3d >>>>>>> >>>>>>> [ 0.000000] [<ffffffff81d22460>] initmem_init+0x9/0xb >>>>>>> >>>>>>> [ 0.000000] [<ffffffff81d0d00c>] setup_arch+0x94f/0xc82 >>>>>>> >>>>>>> [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120 >>>>>>> >>>>>>> [ 0.000000] [<ffffffff817bd0bb>] ? printk+0x55/0x6b >>>>>>> >>>>>>> [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120 >>>>>>> >>>>>>> [ 0.000000] [<ffffffff81d05d9b>] start_kernel+0xe8/0x4d6 >>>>>>> >>>>>>> [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120 >>>>>>> >>>>>>> [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120 >>>>>>> >>>>>>> [ 0.000000] [<ffffffff81d055ee>] >>>>>>> x86_64_start_reservations+0x2a/0x2c >>>>>>> [ 0.000000] [<ffffffff81d05751>] x86_64_start_kernel+0x161/0x184 >>>>>>> >>>>>>> [ 0.000000] RIP 0x46 >>>>>>> >>>>>>> >>>>>>> This is caused by writing over end of numa mask bitmap. >>>>>>> >>>>>>> numa_clear_kernel_node try to set node id in a mask bitmap, it >>>>>>> iterating all >>>>>>> reserved region and assume every regions have valid nid. It is not true >>>>>>> because >>>>>>> There's an exception for graphic memory quirks. see function >>>>>>> trim_snb_memory >>>>>>> in arch/x86/kernel/setup.c >>>>>>> >>>>>>> It is easily to reproduce the bug in kdump kernel because kdump kernel >>>>>>> use >>>>>>> prereserved memory instead of whole memory, but kexec pass other >>>>>>> reserved memory >>>>>>> ranges to 2nd kernel as well. like below in my test: >>>>>>> kdump kernel ram 0x2d000000 - 0x37bfffff >>>>>>> One of the reserved regions: 0x40000000 - 0x40100000 >>>>>>> >>>>>>> The above reserved region includes 0x40004000, a page excluded in >>>>>>> trim_snb_memory. For this memblock reserved region the nid is not set >>>>>>> it is >>>>>>> still default value MAX_NUMNODES. later node_set callback will set bit >>>>>>> MAX_NUMNODES in nodemask bitmap thus stack corruption happen. >>>>>>> >>>>> >>>>> Hi Dave, >>>>> >>>>> Is it means, first reserved region 0x40000000 - 0x40100000, then boot the >>>>> kdump >>>>> kernel, so this region is not include in "numa_meminfo", and >>>>> memblock.reserved >>>>> (0x40004000) is still MAX_NUMNODES from trim_snb_memory(). >>>> >>>> Right, btw, I booted kdump kernel with numa=off for saving memory. >>>> >>>> I suspect it will also be reproduced with mem=XYZ with normal kernel. >>>> >>> >>> cc Tang Chen, numa_clear_kernel_node_hotplug() is original written by him. >>> >>> Hi Dave, >>> I tested the problem, and find the kdump's "numa_meminfo" is the same as >>> the first >>> kernel. I did not set "numa=off" in kdump kernel, maybe this will lead to >>> the >>> difference of "numa_meminfo" >>> >> >> Hi Dave, >> >> I find the reason, it's "dummy_numa_init() -> numa_add_memblk(0, 0, >> PFN_PHYS(max_pfn));", >> this lead to the difference of "numa_meminfo" when set "numa=off". >> >> However we should fix the bug when set "numa=off". > > So do you means MAXPFN should include non system ram region at the end? >
No, I means when set "numa=off", numa_meminfo comes from max_pfn, this makes the difference. and max_pfn is come from e820, not SRAT tables. if no "numa=off", SRAT tables will fill the numa_meminfo. Thanks, Xishi Qiu > The case like below, I believe max_pfn is set to the end of system ram > currently: > [what ever] [ system ram ] [ bios reserved region ] > > Thanks > Dave > > . > -- 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/
