The memcg code can trap tasks in the context of the failing allocation until an OOM situation is resolved. They can hold all kinds of locks (fs, mm) at this point, which makes it prone to deadlocking.
This series converts memcg OOM handling into a two step process that is started in the charge context, but any waiting is done after the fault stack is fully unwound. Patches 1-4 prepare architecture handlers to support the new memcg requirements, but in doing so they also remove old cruft and unify out-of-memory behavior across architectures. Patch 5 disables the memcg OOM handling for syscalls, readahead, kernel faults, because they can gracefully unwind the stack with -ENOMEM. OOM handling is restricted to user triggered faults that have no other option. Patch 6 implements the two-part OOM handling such that tasks are never trapped with the full charge stack in an OOM situation. arch/alpha/mm/fault.c | 7 ++++--- arch/arc/mm/fault.c | 11 ++++------- arch/arm/mm/fault.c | 23 +++++++++++++---------- arch/arm64/mm/fault.c | 23 +++++++++++++---------- arch/avr32/mm/fault.c | 4 +++- arch/cris/mm/fault.c | 6 ++++-- arch/frv/mm/fault.c | 10 ++++++---- arch/hexagon/mm/vm_fault.c | 6 ++++-- arch/ia64/mm/fault.c | 6 ++++-- arch/m32r/mm/fault.c | 10 ++++++---- arch/m68k/mm/fault.c | 2 ++ arch/metag/mm/fault.c | 6 ++++-- arch/microblaze/mm/fault.c | 7 +++++-- arch/mips/mm/fault.c | 8 ++++++-- arch/mn10300/mm/fault.c | 2 ++ arch/openrisc/mm/fault.c | 1 + arch/parisc/mm/fault.c | 7 +++++-- arch/powerpc/mm/fault.c | 7 ++++--- arch/s390/mm/fault.c | 2 ++ arch/score/mm/fault.c | 13 ++++++------- arch/sh/mm/fault.c | 9 ++++++--- arch/sparc/mm/fault_32.c | 12 +++++++++--- arch/sparc/mm/fault_64.c | 8 +++++--- arch/tile/mm/fault.c | 13 +++++-------- arch/um/kernel/trap.c | 22 ++++++++++++++-------- arch/unicore32/mm/fault.c | 22 +++++++++++++--------- arch/x86/mm/fault.c | 43 ++++++++++++++++++++++--------------------- arch/xtensa/mm/fault.c | 2 ++ include/linux/memcontrol.h | 40 ++++++++++++++++++++++++++++++++++++++++ include/linux/mm.h | 1 + include/linux/sched.h | 6 ++++++ mm/filemap.c | 11 ++++++++++- mm/memcontrol.c | 156 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---------------------------------------------------- mm/memory.c | 43 +++++++++++++++++++++++++++++++++---------- mm/oom_kill.c | 7 +++++-- 35 files changed, 373 insertions(+), 183 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
