Messages in this thread | | | Date | Wed, 14 Jul 2004 19:44:47 -0700 | From | William Lee Irwin III <> | Subject | Re: VM Problems in 2.6.7 (Too active OOM Killer) |
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On Wed, Jul 14, 2004 at 07:39:51PM -0700, William Lee Irwin III wrote: > Careful not to make too much of ignoring signals, mm/oom_kill.c sets > PF_MEMDIE out-of-context, so when an OOM kill is issued while a task > is looping in __alloc_pages() it will eventually break out of the > rebalance loop due to the flag.
However, note the modifications of task->flags are not atomic. In principle, one may have:
__alloc_pages() __oom_kill_task() load current->flags load current->flags |= PF_MEMALLOC in registers |= PF_MEMALLOC|PF_MEMDIE in registers IRQ/delay/whatever store current->flags store current->flags ... try_to_free_pages() etc. force_sig() etc.
... and voila! PF_MEMDIE in ->flags has been lost.
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