>> 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. >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
