Hi Barry, On Sun, Apr 07, 2024 at 04:22:47PM +1200, Barry Song wrote: > >> tree: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-unstable > >> head: f43b3aae94511d62174c3b29239da0dd22d0eeb3 > >> commit: d4358ee0a075e232114dfec0cd162860cfa2771b [313/322] mm: add per-order mTHP anon_alloc and anon_alloc_fallback counters > >> config: powerpc-allyesconfig (https://download.01.org/0day-ci/archive/20240406/202404061754.n8jmZ6s3-lkp@xxxxxxxxx/config) > >> compiler: clang version 19.0.0git (https://github.com/llvm/llvm-project 546dc2245ffc4cccd0b05b58b7a5955e355a3b27) > >> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240406/202404061754.n8jmZ6s3-lkp@xxxxxxxxx/reproduce) > >> > >> If you fix the issue in a separate patch/commit (i.e. not just a new version of > >> the same patch/commit), kindly add following tags > >> | Reported-by: kernel test robot <lkp@xxxxxxxxx> > >> | Closes: https://lore.kernel.org/oe-kbuild-all/202404061754.n8jmZ6s3-lkp@xxxxxxxxx/ > >> > >> All error/warnings (new ones prefixed by >>): > >> > >> In file included from arch/powerpc/kernel/asm-offsets.c:19: > >> In file included from include/linux/mman.h:5: > >> In file included from include/linux/mm.h:1115: > >>>> include/linux/huge_mm.h:274:22: warning: variable length array used [-Wvla] > >> 274 | unsigned long stats[PMD_ORDER + 1][__MTHP_STAT_COUNT]; > > | ^~~~~~~~~~~~~ > > > > This is amazing. powerpc's PMD_ORDER isn't const. I will > > move to alloc_percpu instead of using a static array. > > As replied in another thread, can you please test the below patch? > this is v2 combining the fix and the fix of the fix. This v2 patch fixes the errors/warnings reported in both this thread and thread [1]. [1] https://lore.kernel.org/all/202404061627.ungVloow-lkp@xxxxxxxxx/ Tested-by: Yujie Liu <yujie.liu@xxxxxxxxx> > From 6f8604a51ff3333be467e2a681a1f1e8a5d41c48 Mon Sep 17 00:00:00 2001 > From: Barry Song <v-songbaohua@xxxxxxxx> > Date: Sun, 7 Apr 2024 12:23:35 +1200 > Subject: [PATCH v2] mm: fix powerpc build issue > > On powerpc, PMD_ORDER is not a constant variable. We should transition > to using alloc_percpu instead of a static percpu array. > > Signed-off-by: Barry Song <v-songbaohua@xxxxxxxx> > --- > include/linux/huge_mm.h | 9 ++++----- > mm/huge_memory.c | 12 ++++++++++-- > 2 files changed, 14 insertions(+), 7 deletions(-) > > diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h > index c5d33017a4dd..0717063dc5e7 100644 > --- a/include/linux/huge_mm.h > +++ b/include/linux/huge_mm.h > @@ -271,16 +271,15 @@ enum mthp_stat_item { > }; > > struct mthp_stat { > - unsigned long stats[PMD_ORDER + 1][__MTHP_STAT_COUNT]; > + unsigned long stats[0][__MTHP_STAT_COUNT]; > }; > > -DECLARE_PER_CPU(struct mthp_stat, mthp_stats); > +extern struct mthp_stat __percpu *mthp_stats; > > static inline void count_mthp_stat(int order, enum mthp_stat_item item) > { > - if (unlikely(order > PMD_ORDER)) > - return; > - this_cpu_inc(mthp_stats.stats[order][item]); > + if (likely(order <= PMD_ORDER)) > + raw_cpu_ptr(mthp_stats)->stats[order][item]++; > } > > #define transparent_hugepage_use_zero_page() \ > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index 5b875f0fc923..7a72760dc1ce 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -526,7 +526,7 @@ static const struct kobj_type thpsize_ktype = { > .sysfs_ops = &kobj_sysfs_ops, > }; > > -DEFINE_PER_CPU(struct mthp_stat, mthp_stats) = {{{0}}}; > +struct mthp_stat __percpu *mthp_stats; > > static unsigned long sum_mthp_stat(int order, enum mthp_stat_item item) > { > @@ -534,7 +534,7 @@ static unsigned long sum_mthp_stat(int order, enum mthp_stat_item item) > int cpu; > > for_each_online_cpu(cpu) { > - struct mthp_stat *this = &per_cpu(mthp_stats, cpu); > + struct mthp_stat *this = per_cpu_ptr(mthp_stats, cpu); > > sum += this->stats[order][item]; > } > @@ -636,6 +636,13 @@ static int __init hugepage_init_sysfs(struct kobject **hugepage_kobj) > goto remove_hp_group; > } > > + mthp_stats = __alloc_percpu((PMD_ORDER + 1) * sizeof(mthp_stats->stats[0]), > + sizeof(unsigned long)); > + if (!mthp_stats) { > + err = -ENOMEM; > + goto remove_hp_group; > + } > + > orders = THP_ORDERS_ALL_ANON; > order = highest_order(orders); > while (orders) { > @@ -673,6 +680,7 @@ static void __init hugepage_exit_sysfs(struct kobject *hugepage_kobj) > sysfs_remove_group(hugepage_kobj, &khugepaged_attr_group); > sysfs_remove_group(hugepage_kobj, &hugepage_attr_group); > kobject_put(hugepage_kobj); > + free_percpu(mthp_stats); > } > #else > static inline int hugepage_init_sysfs(struct kobject **hugepage_kobj) > -- > 2.34.1 > > >
