https://github.com/torvalds/linux
Revision 146fbb766934dc003fcbf755b519acef683576bf authored by Andrey Ryabinin on 10 February 2017, 09:54:05 UTC, committed by Thomas Gleixner on 10 February 2017, 10:00:23 UTC
CONFIG_KASAN=y needs a lot of virtual memory mapped for its shadow. In that case ptdump_walk_pgd_level_core() takes a lot of time to walk across all page tables and doing this without a rescheduling causes soft lockups: NMI watchdog: BUG: soft lockup - CPU#3 stuck for 23s! [swapper/0:1] ... Call Trace: ptdump_walk_pgd_level_core+0x40c/0x550 ptdump_walk_pgd_level_checkwx+0x17/0x20 mark_rodata_ro+0x13b/0x150 kernel_init+0x2f/0x120 ret_from_fork+0x2c/0x40 I guess that this issue might arise even without KASAN on huge machines with several terabytes of RAM. Stick cond_resched() in pgd loop to fix this. Reported-by: Tobias Regnery <tobias.regnery@gmail.com> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: kasan-dev@googlegroups.com Cc: Alexander Potapenko <glider@google.com> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20170210095405.31802-1-aryabinin@virtuozzo.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
1 parent 5f2e71e
Tip revision: 146fbb766934dc003fcbf755b519acef683576bf authored by Andrey Ryabinin on 10 February 2017, 09:54:05 UTC
x86/mm/ptdump: Fix soft lockup in page table walker
x86/mm/ptdump: Fix soft lockup in page table walker
Tip revision: 146fbb7
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| .cocciconfig | -rw-r--r-- | 59 bytes |
| .get_maintainer.ignore | -rw-r--r-- | 31 bytes |
| .gitattributes | -rw-r--r-- | 30 bytes |
| .gitignore | -rw-r--r-- | 1.3 KB |
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| COPYING | -rw-r--r-- | 18.3 KB |
| CREDITS | -rw-r--r-- | 96.0 KB |
| Kbuild | -rw-r--r-- | 2.8 KB |
| Kconfig | -rw-r--r-- | 252 bytes |
| MAINTAINERS | -rw-r--r-- | 383.0 KB |
| Makefile | -rw-r--r-- | 57.7 KB |
| README | -rw-r--r-- | 722 bytes |
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