Tidy things up and delete comments stating the obvious with typos or
making no sense.
Signed-off-by: Yu Zhao <yuzhao@xxxxxxxxxx>
---
include/linux/page-flags-layout.h | 62 +++++++++++++++----------------
mm/mm_init.c | 4 --
2 files changed, 29 insertions(+), 37 deletions(-)
diff --git a/include/linux/page-flags-layout.h b/include/linux/page-flags-layout.h
index 295c2c687d2c..ef1e3e736e14 100644
--- a/include/linux/page-flags-layout.h
+++ b/include/linux/page-flags-layout.h
@@ -21,16 +21,17 @@
#elif MAX_NR_ZONES <= 8
#define ZONES_SHIFT 3
#else
-#error ZONES_SHIFT -- too many zones configured adjust calculation
+#error ZONES_SHIFT "Too many zones configured"
#endif
+#define ZONES_WIDTH ZONES_SHIFT
+
#ifdef CONFIG_SPARSEMEM
#include <asm/sparsemem.h>
-
-/* SECTION_SHIFT #bits space required to store a section # */
#define SECTIONS_SHIFT (MAX_PHYSMEM_BITS - SECTION_SIZE_BITS)
-
-#endif /* CONFIG_SPARSEMEM */
+#else
+#define SECTIONS_SHIFT 0
+#endif
#ifndef BUILD_VDSO32_64
/*
@@ -54,17 +55,28 @@
#define SECTIONS_WIDTH 0
#endif
-#define ZONES_WIDTH ZONES_SHIFT
-
-#if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT <= BITS_PER_LONG - NR_PAGEFLAGS
+#if ZONES_WIDTH + SECTIONS_WIDTH + NODES_SHIFT <= BITS_PER_LONG - NR_PAGEFLAGS
#define NODES_WIDTH NODES_SHIFT
-#else
-#ifdef CONFIG_SPARSEMEM_VMEMMAP
+#elif defined(CONFIG_SPARSEMEM_VMEMMAP)
#error "Vmemmap: No space for nodes field in page flags"
-#endif
+#else
#define NODES_WIDTH 0
#endif
+/*
+ * Note that this #define MUST have a value so that it can be tested with
+ * the IS_ENABLED() macro.
+ */
+#if NODES_SHIFT != 0 && NODES_WIDTH == 0
+#define NODE_NOT_IN_PAGE_FLAGS 1
+#endif
+
+#if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
+#define KASAN_TAG_WIDTH 8
+#else
+#define KASAN_TAG_WIDTH 0
+#endif
+
#ifdef CONFIG_NUMA_BALANCING
#define LAST__PID_SHIFT 8
#define LAST__PID_MASK ((1 << LAST__PID_SHIFT)-1)
@@ -77,37 +89,21 @@
#define LAST_CPUPID_SHIFT 0
#endif
-#if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
-#define KASAN_TAG_WIDTH 8
-#else
-#define KASAN_TAG_WIDTH 0
-#endif
-
-#if SECTIONS_WIDTH+ZONES_WIDTH+NODES_WIDTH+LAST_CPUPID_SHIFT+KASAN_TAG_WIDTH \
+#if ZONES_WIDTH + SECTIONS_WIDTH + NODES_WIDTH + KASAN_TAG_WIDTH + LAST_CPUPID_SHIFT \
<= BITS_PER_LONG - NR_PAGEFLAGS
#define LAST_CPUPID_WIDTH LAST_CPUPID_SHIFT
#else
#define LAST_CPUPID_WIDTH 0
#endif
-#if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH+LAST_CPUPID_WIDTH+KASAN_TAG_WIDTH \
+#if LAST_CPUPID_SHIFT != 0 && LAST_CPUPID_WIDTH == 0
+#define LAST_CPUPID_NOT_IN_PAGE_FLAGS
+#endif
+
+#if ZONES_WIDTH + SECTIONS_WIDTH + NODES_WIDTH + KASAN_TAG_WIDTH + LAST_CPUPID_WIDTH \
> BITS_PER_LONG - NR_PAGEFLAGS
#error "Not enough bits in page flags"
#endif
-/*
- * We are going to use the flags for the page to node mapping if its in
- * there. This includes the case where there is no node, so it is implicit.
- * Note that this #define MUST have a value so that it can be tested with
- * the IS_ENABLED() macro.
- */
-#if !(NODES_WIDTH > 0 || NODES_SHIFT == 0)
-#define NODE_NOT_IN_PAGE_FLAGS 1
-#endif
-
-#if defined(CONFIG_NUMA_BALANCING) && LAST_CPUPID_WIDTH == 0
-#define LAST_CPUPID_NOT_IN_PAGE_FLAGS
-#endif
-
#endif
#endif /* _LINUX_PAGE_FLAGS_LAYOUT */
diff --git a/mm/mm_init.c b/mm/mm_init.c
index 8e02e865cc65..9ddaf0e1b0ab 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -19,10 +19,6 @@
#ifdef CONFIG_DEBUG_MEMORY_INIT
int __meminitdata mminit_loglevel;
-#ifndef SECTIONS_SHIFT
-#define SECTIONS_SHIFT 0
-#endif
-
/* The zonelists are simply reported, validation is manual. */
void __init mminit_verify_zonelist(void)
{
--
2.30.1.766.gb4fecdf3b7-goog
