3 files changed, 27 insertions, 3 deletions

diff --git a/include/asm-generic/percpu.h b/include/asm-generic/percpu.h
index 0504ef8f3aa3..976f8ac26665 100644
--- a/include/asm-generic/percpu.h
+++ b/include/asm-generic/percpu.h
@@ -115,15 +115,35 @@ do {									\
         (__ret);                                                        \
 })
 
-#define this_cpu_generic_read(pcp)                                      \
+#define __this_cpu_generic_read_nopreempt(pcp)                          \
 ({                                                                      \
         typeof(pcp) __ret;                                              \
         preempt_disable_notrace();                                      \
-        __ret = raw_cpu_generic_read(pcp);                              \
+        __ret = READ_ONCE(*raw_cpu_ptr(&(pcp)));                        \
         preempt_enable_notrace();                                       \
         __ret;                                                          \
 })
 
+#define __this_cpu_generic_read_noirq(pcp)                              \
+({                                                                      \
+        typeof(pcp) __ret;                                              \
+        unsigned long __flags;                                          \
+        raw_local_irq_save(__flags);                                    \
+        __ret = raw_cpu_generic_read(pcp);                              \
+        raw_local_irq_restore(__flags);                                 \
+        __ret;                                                          \
+})
+
+#define this_cpu_generic_read(pcp)                                      \
+({                                                                      \
+        typeof(pcp) __ret;                                              \
+        if (__native_word(pcp))                                         \
+                __ret = __this_cpu_generic_read_nopreempt(pcp);         \
+        else                                                            \
+                __ret = __this_cpu_generic_read_noirq(pcp);             \
+        __ret;                                                          \
+})
+
 #define this_cpu_generic_to_op(pcp, val, op)                            \
 do {                                                                    \
         unsigned long __flags;                                          \
diff --git a/mm/percpu-stats.c b/mm/percpu-stats.c
index 6142484e88f7..7a58460bfd27 100644
--- a/mm/percpu-stats.c
+++ b/mm/percpu-stats.c
@@ -73,7 +73,7 @@ static void chunk_map_stats(struct seq_file *m, struct pcpu_chunk *chunk,
                      last_alloc + 1 : 0;
 
         as_len = 0;
-        start = chunk->start_offset;
+        start = chunk->start_offset / PCPU_MIN_ALLOC_SIZE;
 
         /*
          * If a bit is set in the allocation map, the bound_map identifies
diff --git a/mm/percpu.c b/mm/percpu.c
index 59d44d61f5f1..aa121cef76de 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -353,6 +353,8 @@ static void pcpu_next_md_free_region(struct pcpu_chunk *chunk, int *bit_off,
                                         block->contig_hint_start);
                         return;
                 }
+                /* reset to satisfy the second predicate above */
+                block_off = 0;
 
                 *bits = block->right_free;
                 *bit_off = (i + 1) * PCPU_BITMAP_BLOCK_BITS - block->right_free;
@@ -407,6 +409,8 @@ static void pcpu_next_fit_region(struct pcpu_chunk *chunk, int alloc_bits,
                         *bit_off = pcpu_block_off_to_off(i, block->first_free);
                         return;
                 }
+                /* reset to satisfy the second predicate above */
+                block_off = 0;
 
                 *bit_off = ALIGN(PCPU_BITMAP_BLOCK_BITS - block->right_free,
                                  align);