The patch titled
Subject: mm: Fix clang W=1 compiler warnings
has been added to the -mm mm-unstable branch. Its filename is
mm-fix-clang-w=1-compiler-warnings.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-fix-clang-w=1-compiler-warnings.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Bart Van Assche <bvanassche@xxxxxxx>
Subject: mm: Fix clang W=1 compiler warnings
Date: Fri, 31 Jan 2025 11:12:23 -0800
Commit 30c2de0a267c ("mm/vmstat: fix a W=1 clang compiler warning")
suppresses some but not all compiler warnings that are reported by clang
when building mm/ with W=1. Hence revert commit 30c2de0a267c and instead
make NR_LRU_BASE and NR_ZONE_LRU_BASE integer constants instead of
enumeration constants. Additionally, convert the item##_NORMAL constants
from type enum vm_event_item into int before subtracting ZONE_NORMAL. The
latter constant has type enum zone_type.
Link: https://lkml.kernel.org/r/20250131191231.1370466-1-bvanassche@xxxxxxx
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
Cc: Ivan Shapovalov <intelfx@xxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: David Laight <david.laight@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Joel Granados <joel.granados@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Kaiyang Zhao <kaiyang2@xxxxxxxxxx>
Cc: Nathan Chancellor <nathan@xxxxxxxxxx>
Cc: Pasha Tatashin <pasha.tatashin@xxxxxxxxxx>
Cc: Sourav Panda <souravpanda@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mmzone.h | 26 +++++++++++++++++++++-----
include/linux/vmstat.h | 9 +++++++--
2 files changed, 28 insertions(+), 7 deletions(-)
--- a/include/linux/mmzone.h~mm-fix-clang-w=1-compiler-warnings
+++ a/include/linux/mmzone.h
@@ -135,11 +135,20 @@ enum numa_stat_item {
#define NR_VM_NUMA_EVENT_ITEMS 0
#endif
+/*
+ * NR_ZONE_LRU_BASE and NR_VM_ZONE_STAT_ITEMS are often added to enumeration
+ * constants of another type than enum_zone_stat_item. Define these constants
+ * as an integer instead of enum node_stat_item to prevent that the compiler
+ * warns about enumeration type mismatches when these constants are used.
+ */
+#define NR_ZONE_LRU_BASE (__NR_ZONE_LRU_BASE + 0)
+#define NR_VM_ZONE_STAT_ITEMS (__NR_VM_ZONE_STAT_ITEMS + 0)
+
enum zone_stat_item {
/* First 128 byte cacheline (assuming 64 bit words) */
NR_FREE_PAGES,
- NR_ZONE_LRU_BASE, /* Used only for compaction and reclaim retry */
- NR_ZONE_INACTIVE_ANON = NR_ZONE_LRU_BASE,
+ __NR_ZONE_LRU_BASE, /* Used only for compaction and reclaim retry */
+ NR_ZONE_INACTIVE_ANON = __NR_ZONE_LRU_BASE,
NR_ZONE_ACTIVE_ANON,
NR_ZONE_INACTIVE_FILE,
NR_ZONE_ACTIVE_FILE,
@@ -155,11 +164,18 @@ enum zone_stat_item {
#ifdef CONFIG_UNACCEPTED_MEMORY
NR_UNACCEPTED,
#endif
- NR_VM_ZONE_STAT_ITEMS };
+ __NR_VM_ZONE_STAT_ITEMS };
+
+/*
+ * enum lru_list constants are often added to NR_LRU_BASE. Define NR_LRU_BASE
+ * as an integer instead of enum node_stat_item to prevent that the compiler
+ * warns about enumeration type mismatches.
+ */
+#define NR_LRU_BASE (__NR_LRU_BASE + 0)
enum node_stat_item {
- NR_LRU_BASE,
- NR_INACTIVE_ANON = NR_LRU_BASE, /* must match order of LRU_[IN]ACTIVE */
+ __NR_LRU_BASE,
+ NR_INACTIVE_ANON = __NR_LRU_BASE, /*must match order of LRU_[IN]ACTIVE*/
NR_ACTIVE_ANON, /* " " " " " */
NR_INACTIVE_FILE, /* " " " " " */
NR_ACTIVE_FILE, /* " " " " " */
--- a/include/linux/vmstat.h~mm-fix-clang-w=1-compiler-warnings
+++ a/include/linux/vmstat.h
@@ -135,8 +135,13 @@ static inline void vm_events_fold_cpu(in
#define count_vm_vma_lock_event(x) do {} while (0)
#endif
+/*
+ * item##_NORMAL has type enum vm_event_item while ZONE_NORMAL and zid have
+ * type enum zone_type. Suppress compiler warnings about mixing different
+ * enumeration types by converting item##_NORMAL into an int with '+ 0'.
+ */
#define __count_zid_vm_events(item, zid, delta) \
- __count_vm_events(item##_NORMAL - ZONE_NORMAL + zid, delta)
+ __count_vm_events((item##_NORMAL + 0) - ZONE_NORMAL + zid, delta)
/*
* Zone and node-based page accounting with per cpu differentials.
@@ -515,7 +520,7 @@ static inline const char *node_stat_name
static inline const char *lru_list_name(enum lru_list lru)
{
- return node_stat_name(NR_LRU_BASE + (enum node_stat_item)lru) + 3; // skip "nr_"
+ return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
}
#if defined(CONFIG_VM_EVENT_COUNTERS) || defined(CONFIG_MEMCG)
_
Patches currently in -mm which might be from bvanassche@xxxxxxx are
procfs-fix-a-locking-bug-in-a-vmcore_add_device_dump-error-path.patch
mm-fix-clang-w=1-compiler-warnings.patch
