[PATCH] mm/cma: Remove CONFIG_CMA_SYSFS option

[Jean Delvare <jdelvare@suse.de>]

The sysfs interface to CMA has a marginal runtime cost and a small
footprint, there's no reason not to include it in all kernels where
the dependencies are satisfied.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
---
As discussed with David:
  https://lkml.org/lkml/2025/8/6/371

 arch/loongarch/configs/loongson3_defconfig |    1 -
 arch/s390/configs/debug_defconfig          |    1 -
 arch/s390/configs/defconfig                |    1 -
 mm/Kconfig                                 |    7 -------
 mm/Makefile                                |    4 +++-
 mm/cma.h                                   |    4 ++--
 6 files changed, 5 insertions(+), 13 deletions(-)

--- linux-6.17.orig/arch/loongarch/configs/loongson3_defconfig
+++ linux-6.17/arch/loongarch/configs/loongson3_defconfig
@@ -120,7 +120,6 @@ CONFIG_MEMORY_HOTREMOVE=y
 CONFIG_KSM=y
 CONFIG_TRANSPARENT_HUGEPAGE=y
 CONFIG_CMA=y
-CONFIG_CMA_SYSFS=y
 CONFIG_USERFAULTFD=y
 CONFIG_NET=y
 CONFIG_PACKET=y
--- linux-6.17.orig/arch/s390/configs/debug_defconfig
+++ linux-6.17/arch/s390/configs/debug_defconfig
@@ -103,7 +103,6 @@ CONFIG_MEMORY_HOTREMOVE=y
 CONFIG_KSM=y
 CONFIG_TRANSPARENT_HUGEPAGE=y
 CONFIG_CMA_DEBUGFS=y
-CONFIG_CMA_SYSFS=y
 CONFIG_CMA_AREAS=7
 CONFIG_MEM_SOFT_DIRTY=y
 CONFIG_DEFERRED_STRUCT_PAGE_INIT=y
--- linux-6.17.orig/arch/s390/configs/defconfig
+++ linux-6.17/arch/s390/configs/defconfig
@@ -95,7 +95,6 @@ CONFIG_MEMORY_HOTPLUG=y
 CONFIG_MEMORY_HOTREMOVE=y
 CONFIG_KSM=y
 CONFIG_TRANSPARENT_HUGEPAGE=y
-CONFIG_CMA_SYSFS=y
 CONFIG_CMA_AREAS=7
 CONFIG_MEM_SOFT_DIRTY=y
 CONFIG_DEFERRED_STRUCT_PAGE_INIT=y
--- linux-6.17.orig/mm/Makefile
+++ linux-6.17/mm/Makefile
@@ -119,6 +119,9 @@ obj-$(CONFIG_ZPOOL)	+= zpool.o
 obj-$(CONFIG_ZSMALLOC)	+= zsmalloc.o
 obj-$(CONFIG_GENERIC_EARLY_IOREMAP) += early_ioremap.o
 obj-$(CONFIG_CMA)	+= cma.o
+ifdef CONFIG_SYSFS
+obj-$(CONFIG_CMA)	+= cma_sysfs.o
+endif
 obj-$(CONFIG_NUMA) += numa.o
 obj-$(CONFIG_NUMA_MEMBLKS) += numa_memblks.o
 obj-$(CONFIG_NUMA_EMU) += numa_emulation.o
@@ -127,7 +130,6 @@ obj-$(CONFIG_PAGE_EXTENSION) += page_ext
 obj-$(CONFIG_PAGE_TABLE_CHECK) += page_table_check.o
 obj-$(CONFIG_CMA_DEBUGFS) += cma_debug.o
 obj-$(CONFIG_SECRETMEM) += secretmem.o
-obj-$(CONFIG_CMA_SYSFS) += cma_sysfs.o
 obj-$(CONFIG_USERFAULTFD) += userfaultfd.o
 obj-$(CONFIG_IDLE_PAGE_TRACKING) += page_idle.o
 obj-$(CONFIG_DEBUG_PAGEALLOC) += debug_page_alloc.o
--- linux-6.17.orig/mm/cma.h
+++ linux-6.17/mm/cma.h
@@ -49,7 +49,7 @@ struct cma {
 	char name[CMA_MAX_NAME];
 	int nranges;
 	struct cma_memrange ranges[CMA_MAX_RANGES];
-#ifdef CONFIG_CMA_SYSFS
+#ifdef CONFIG_SYSFS
 	/* the number of CMA page successful allocations */
 	atomic64_t nr_pages_succeeded;
 	/* the number of CMA page allocation failures */
@@ -80,7 +80,7 @@ static inline unsigned long cma_bitmap_m
 	return cmr->count >> cma->order_per_bit;
 }
 
-#ifdef CONFIG_CMA_SYSFS
+#ifdef CONFIG_SYSFS
 void cma_sysfs_account_success_pages(struct cma *cma, unsigned long nr_pages);
 void cma_sysfs_account_fail_pages(struct cma *cma, unsigned long nr_pages);
 void cma_sysfs_account_release_pages(struct cma *cma, unsigned long nr_pages);
--- linux-6.17.orig/mm/Kconfig
+++ linux-6.17/mm/Kconfig
@@ -981,13 +981,6 @@ config CMA_DEBUGFS
 	help
 	  Turns on the DebugFS interface for CMA.
 
-config CMA_SYSFS
-	bool "CMA information through sysfs interface"
-	depends on CMA && SYSFS
-	help
-	  This option exposes some sysfs attributes to get information
-	  from CMA.
-
 config CMA_AREAS
 	int "Maximum count of the CMA areas"
 	depends on CMA


-- 
Jean Delvare
SUSE L3 Support