On Mon 06-11-17 11:05:58, Peter Zijlstra wrote: > 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.
Which suggests that print_vma_addr might be problematic, right? Shouldn't we do trylock on mmap_sem instead? -- Michal Hocko SUSE Labs
