[PATCH v2 1/3] mm: convert memory block states (MEM_*) macros to enum

Israel Batista <[email protected]> Wed, 29 Oct 2025 19:56:28 +0000 (UTC)
Newsgroups org.kernel.vger.linux-debuggers,org.kvack.linux-mm
Message-ID <[email protected]>
Converting the MEM_* constants from macros to an enum ensures that their
values will be correctly emitted in the debug symbols, making it easier
to trace the meaning of each value when debugging with tools such as
drgn, without the need to hard-code the values.

Since the values are mutually exclusive and they are not exposed directly to
userspace, I also dropped the misleading pattern (1<<X) that made it look like
they were combinable flags.

Signed-off-by: Israel Batista <[email protected]>
---
 include/linux/memory.h | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/include/linux/memory.h b/include/linux/memory.h
index 0c214256216f..f4e358477c6a 100644
--- a/include/linux/memory.h
+++ b/include/linux/memory.h
@@ -64,6 +64,18 @@ struct memory_group {
 	};
 };
 
+enum memory_block_state {
+	/* These states are exposed to userspace as text strings in sysfs */
+	MEM_ONLINE,		/* exposed to userspace */
+	MEM_GOING_OFFLINE,	/* exposed to userspace */
+	MEM_OFFLINE,		/* exposed to userspace */
+	MEM_GOING_ONLINE,
+	MEM_CANCEL_ONLINE,
+	MEM_CANCEL_OFFLINE,
+	MEM_PREPARE_ONLINE,
+	MEM_FINISH_OFFLINE,
+};
+
 struct memory_block {
 	unsigned long start_section_nr;
 	unsigned long state;		/* serialized by the dev->lock */
@@ -89,16 +101,6 @@ int arch_get_memory_phys_device(unsigned long start_pfn);
 unsigned long memory_block_size_bytes(void);
 int set_memory_block_size_order(unsigned int order);
 
-/* These states are exposed to userspace as text strings in sysfs */
-#define	MEM_ONLINE		(1<<0) /* exposed to userspace */
-#define	MEM_GOING_OFFLINE	(1<<1) /* exposed to userspace */
-#define	MEM_OFFLINE		(1<<2) /* exposed to userspace */
-#define	MEM_GOING_ONLINE	(1<<3)
-#define	MEM_CANCEL_ONLINE	(1<<4)
-#define	MEM_CANCEL_OFFLINE	(1<<5)
-#define	MEM_PREPARE_ONLINE	(1<<6)
-#define	MEM_FINISH_OFFLINE	(1<<7)
-
 struct memory_notify {
 	/*
 	 * The altmap_start_pfn and altmap_nr_pages fields are designated for
-- 
2.51.0