Messages in this thread | | | Date | Tue, 27 Feb 2018 17:33:23 +0000 | From | Will Deacon <> | Subject | Re: [RFC PATCH v2 08/12] arm64: cmpxchg: Include build_bug.h instead of bug.h for BUILD_BUG |
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On Mon, Feb 26, 2018 at 03:48:49PM +0000, Mark Rutland wrote: > On Mon, Feb 26, 2018 at 03:04:56PM +0000, Will Deacon wrote: > > Having asm/cmpxchg.h pull in linux/bug.h is problematic because this > > ends up pulling in the atomic bitops which themselves may be built on > > top of atomic.h and cmpxchg.h. > > > > Instead, just include build_bug.h for the definition of BUILD_BUG. > > We also use VM_BUG_ON(), defined in <linux/mmdebug.h>, which includes > <linux/bug.h>. > > ... so I think we still have some fragility here, albeit no worse than before. > > We also miss includes for: > > * <linux/percpu-defs.h> (raw_cpu_ptr) > * <linux/preempt.h> (preempt_disable, preempt_enable)
Hmm, we can't include this one because it pulls in linux/bitops.h. I've moved the percpu cmpxchg stuff into asm/percpu.h, but that too is missing the linux/preempt.h #include, so I've added that as well.
Generally, I think if we want to clean up our #includes then that's better done as a separate series rather than as a piecemeal effort, which will likely fail to identify many of the underlying problems.
Will
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