Messages in this thread | | | Subject | Re: [PATCH] mm,oom: fix oom invocation issues | From | Tetsuo Handa <> | Date | Thu, 18 May 2017 22:57:10 +0900 |
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Michal Hocko wrote: > It is racy and it basically doesn't have any allocation context so we > might kill a task from a different domain. So can we do this instead? > There is a slight risk that somebody might have returned VM_FAULT_OOM > without doing an allocation but from my quick look nobody does that > currently.
I can't tell whether it is safe to remove out_of_memory() from pagefault_out_of_memory(). There are VM_FAULT_OOM users in fs/ directory. What happens if pagefault_out_of_memory() was called as a result of e.g. GFP_NOFS allocation failure? Is it guaranteed that all memory allocations that might occur from page fault event (or any action that might return VM_FAULT_OOM) are allowed to call oom_kill_process() from out_of_memory() before reaching pagefault_out_of_memory() ?
Anyway, I want
/* Avoid allocations with no watermarks from looping endlessly */ - if (test_thread_flag(TIF_MEMDIE)) + if (alloc_flags == ALLOC_NO_WATERMARKS && test_thread_flag(TIF_MEMDIE)) goto nopage;
so that we won't see similar backtraces and memory information from both out_of_memory() and warn_alloc().
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