Messages in this thread | | | Date | Mon, 6 Nov 2017 11:05:58 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH] mm: use in_atomic() in print_vma_addr() |
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On Sun, Nov 05, 2017 at 09:19:46AM +0100, Michal Hocko wrote: > [CC Peter] > > On Fri 03-11-17 20:09:49, Bart Van Assche wrote: > > On Fri, 2017-11-03 at 11:02 -0700, Andrew Morton wrote: > > > Also, checkpatch says > > > > > > WARNING: use of in_atomic() is incorrect outside core kernel code > > > #43: FILE: mm/memory.c:4491: > > > + if (in_atomic()) > > > > > > I don't recall why we did that, but perhaps this should be revisited? > > > > Is the comment above in_atomic() still up-to-date? From <linux/preempt.h>: > > > > /* > > * Are we running in atomic context? WARNING: this macro cannot > > * always detect atomic context; in particular, it cannot know about > > * held spinlocks in non-preemptible kernels. Thus it should not be > > * used in the general case to determine whether sleeping is possible. > > * Do not use in_atomic() in driver code. > > */ > > #define in_atomic() (preempt_count() != 0) > > I can still see preempt_disable NOOP for !CONFIG_PREEMPT_COUNT kernels > which makes me think this is still a valid comment.
Yes the comment is very much accurate.
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