On 1/21/25 5:57 PM, Ivan Shapovalov wrote:
Spose so. One always suspects that adding a typecast is a sign that we
screwed things up somehow. The relationship between enums lru_list and
node_stat_item is foggy, and I'm unsure whether this is the place to
make the transition it. Perhaps lru_list_name() should take an
`unsigned int' arg instead.
All of these *_name() functions do seem to expect arguments in range of
the corresponding enums, so perhaps keep those args typed as a form of
self-documenting code, and do this instead?
If nobody objects I will submit this patch for review after the merge
window has closed:
Subject: [PATCH] mm/vmstat: Fix W=1 clang compiler warnings
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 with W=1 about NR_LRU_BASE and NR_ZONE_LRU_BASE. Hence
revert commit 30c2de0a267c and instead make NR_LRU_BASE and
NR_ZONE_LRU_BASE integer constants instead of enumeration constants.
Cc: Ivan Shapovalov <intelfx@xxxxxxxxxxxx>
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
include/linux/mmzone.h | 22 +++++++++++++++++++---
include/linux/vmstat.h | 9 +++++++--
2 files changed, 26 insertions(+), 5 deletions(-)
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 9540b41894da..92ed919ea99d 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -135,10 +135,19 @@ 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 (1 * __NR_ZONE_LRU_BASE)
+#define NR_VM_ZONE_STAT_ITEMS (1 * __NR_VM_ZONE_STAT_ITEMS)
+
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_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,
@@ -155,10 +164,17 @@ 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 (1 * __NR_LRU_BASE)
enum node_stat_item {
- NR_LRU_BASE,
+ __NR_LRU_BASE,
NR_INACTIVE_ANON = NR_LRU_BASE, /* must match order of LRU_[IN]ACTIVE */
NR_ACTIVE_ANON, /* " " " " " */
NR_INACTIVE_FILE, /* " " " " " */
diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
index 9f3a04345b86..eb115b9a50f4 100644
--- a/include/linux/vmstat.h
+++ b/include/linux/vmstat.h
@@ -135,8 +135,13 @@ static inline void vm_events_fold_cpu(int cpu)
#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 '1 *'.
+ */
#define __count_zid_vm_events(item, zid, delta) \
- __count_vm_events(item##_NORMAL - ZONE_NORMAL + zid, delta)
+ __count_vm_events(1 * item##_NORMAL - 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(enum
node_stat_item item)
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)
