On Wed, 28 Aug 2024 22:13:49 +0200 Mateusz Guzik <mjguzik@xxxxxxxxx> wrote: > > It's conventional (within MM, at least) to put the section thing at the > > end of the definition, so tweak: > > > > --- a/mm/hugetlb.c~mm-hugetlb-sort-out-global-lock-annotations-fix > > +++ a/mm/hugetlb.c > > @@ -72,14 +72,14 @@ static unsigned int default_hugepages_in > > * Protects updates to hugepage_freelists, hugepage_activelist, nr_huge_pages, > > * free_huge_pages, and surplus_huge_pages. > > */ > > -__cacheline_aligned_in_smp DEFINE_SPINLOCK(hugetlb_lock); > > +DEFINE_SPINLOCK(hugetlb_lock) __cacheline_aligned_in_smp; > > > > I tried things in this order and this does not compile for me: > In file included from ./arch/x86/include/asm/current.h:10, > from ./arch/x86/include/asm/preempt.h:7, > from ./include/linux/preempt.h:79, > from ./include/linux/spinlock.h:56, > from ./include/linux/mmzone.h:8, > from ./include/linux/gfp.h:7, > from ./include/linux/mm.h:7, > from mm/hugetlb.c:8: > ./include/linux/cache.h:80:3: error: expected ‘,’ or ‘;’ before ‘__attribute__’ > 80 | __attribute__((__aligned__(SMP_CACHE_BYTES), \ > | ^~~~~~~~~~~~~ > ./include/linux/cache.h:86:36: note: in expansion of macro ‘__cacheline_aligned’ > 86 | #define __cacheline_aligned_in_smp __cacheline_aligned > | ^~~~~~~~~~~~~~~~~~~ > mm/hugetlb.c:75:31: note: in expansion of macro ‘__cacheline_aligned_in_smp’ > 75 | DEFINE_SPINLOCK(hugetlb_lock) __cacheline_aligned_in_smp; > | ^~~~~~~~~~~~~~~~~~~~~~~~~~ Well that's annoying. It's because DEFINE_SPINLOCK includes an initializer. --- a/mm/hugetlb.c~mm-hugetlb-sort-out-global-lock-annotations-fix-fix +++ a/mm/hugetlb.c @@ -72,7 +72,7 @@ static unsigned int default_hugepages_in * Protects updates to hugepage_freelists, hugepage_activelist, nr_huge_pages, * free_huge_pages, and surplus_huge_pages. */ -DEFINE_SPINLOCK(hugetlb_lock) __cacheline_aligned_in_smp; +spinlock_t hugetlb_lock __cacheline_aligned_in_smp = __SPIN_LOCK_UNLOCKED(hugetlb_lock); /* * Serializes faults on the same logical page. This is used to _ We'd need a new DEFINE_SPINLOCK_ALIGNED() or something. Ho hum, I'll fix.
