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-rw-r--r--Documentation/ABI/testing/sysfs-kernel-mm-cma25
-rw-r--r--mm/Kconfig7
-rw-r--r--mm/Makefile1
-rw-r--r--mm/cma.c8
-rw-r--r--mm/cma.h23
-rw-r--r--mm/cma_sysfs.c112
6 files changed, 174 insertions, 2 deletions
diff --git a/Documentation/ABI/testing/sysfs-kernel-mm-cma b/Documentation/ABI/testing/sysfs-kernel-mm-cma
new file mode 100644
index 000000000000..02b2bb60c296
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-kernel-mm-cma
@@ -0,0 +1,25 @@
+What: /sys/kernel/mm/cma/
+Date: Feb 2021
+Contact: Minchan Kim <minchan@kernel.org>
+Description:
+ /sys/kernel/mm/cma/ contains a subdirectory for each CMA
+ heap name (also sometimes called CMA areas).
+
+ Each CMA heap subdirectory (that is, each
+ /sys/kernel/mm/cma/<cma-heap-name> directory) contains the
+ following items:
+
+ alloc_pages_success
+ alloc_pages_fail
+
+What: /sys/kernel/mm/cma/<cma-heap-name>/alloc_pages_success
+Date: Feb 2021
+Contact: Minchan Kim <minchan@kernel.org>
+Description:
+ the number of pages CMA API succeeded to allocate
+
+What: /sys/kernel/mm/cma/<cma-heap-name>/alloc_pages_fail
+Date: Feb 2021
+Contact: Minchan Kim <minchan@kernel.org>
+Description:
+ the number of pages CMA API failed to allocate
diff --git a/mm/Kconfig b/mm/Kconfig
index f4ceeaedb966..5f7d7b3d8cc2 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -518,6 +518,13 @@ 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
diff --git a/mm/Makefile b/mm/Makefile
index c0135e385984..809033d77710 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -109,6 +109,7 @@ obj-$(CONFIG_CMA) += cma.o
obj-$(CONFIG_MEMORY_BALLOON) += balloon_compaction.o
obj-$(CONFIG_PAGE_EXTENSION) += page_ext.o
obj-$(CONFIG_CMA_DEBUGFS) += cma_debug.o
+obj-$(CONFIG_CMA_SYSFS) += cma_sysfs.o
obj-$(CONFIG_USERFAULTFD) += userfaultfd.o
obj-$(CONFIG_IDLE_PAGE_TRACKING) += page_idle.o
obj-$(CONFIG_DEBUG_PAGE_REF) += debug_page_ref.o
diff --git a/mm/cma.c b/mm/cma.c
index d1a4c06b5039..2380f2571eb5 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -511,10 +511,14 @@ struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align,
pr_debug("%s(): returned %p\n", __func__, page);
out:
- if (page)
+ if (page) {
count_vm_event(CMA_ALLOC_SUCCESS);
- else
+ cma_sysfs_account_success_pages(cma, count);
+ } else {
count_vm_event(CMA_ALLOC_FAIL);
+ if (cma)
+ cma_sysfs_account_fail_pages(cma, count);
+ }
return page;
}
diff --git a/mm/cma.h b/mm/cma.h
index c46c5050aaa9..2c775877eae2 100644
--- a/mm/cma.h
+++ b/mm/cma.h
@@ -3,6 +3,12 @@
#define __MM_CMA_H__
#include <linux/debugfs.h>
+#include <linux/kobject.h>
+
+struct cma_kobject {
+ struct kobject kobj;
+ struct cma *cma;
+};
struct cma {
unsigned long base_pfn;
@@ -16,6 +22,14 @@ struct cma {
struct debugfs_u32_array dfs_bitmap;
#endif
char name[CMA_MAX_NAME];
+#ifdef CONFIG_CMA_SYSFS
+ /* the number of CMA page successful allocations */
+ atomic64_t nr_pages_succeeded;
+ /* the number of CMA page allocation failures */
+ atomic64_t nr_pages_failed;
+ /* kobject requires dynamic object */
+ struct cma_kobject *cma_kobj;
+#endif
};
extern struct cma cma_areas[MAX_CMA_AREAS];
@@ -26,4 +40,13 @@ static inline unsigned long cma_bitmap_maxno(struct cma *cma)
return cma->count >> cma->order_per_bit;
}
+#ifdef CONFIG_CMA_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);
+#else
+static inline void cma_sysfs_account_success_pages(struct cma *cma,
+ unsigned long nr_pages) {};
+static inline void cma_sysfs_account_fail_pages(struct cma *cma,
+ unsigned long nr_pages) {};
+#endif
#endif
diff --git a/mm/cma_sysfs.c b/mm/cma_sysfs.c
new file mode 100644
index 000000000000..eb2f39caff59
--- /dev/null
+++ b/mm/cma_sysfs.c
@@ -0,0 +1,112 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * CMA SysFS Interface
+ *
+ * Copyright (c) 2021 Minchan Kim <minchan@kernel.org>
+ */
+
+#include <linux/cma.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+
+#include "cma.h"
+
+#define CMA_ATTR_RO(_name) \
+ static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
+
+void cma_sysfs_account_success_pages(struct cma *cma, unsigned long nr_pages)
+{
+ atomic64_add(nr_pages, &cma->nr_pages_succeeded);
+}
+
+void cma_sysfs_account_fail_pages(struct cma *cma, unsigned long nr_pages)
+{
+ atomic64_add(nr_pages, &cma->nr_pages_failed);
+}
+
+static inline struct cma *cma_from_kobj(struct kobject *kobj)
+{
+ return container_of(kobj, struct cma_kobject, kobj)->cma;
+}
+
+static ssize_t alloc_pages_success_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ struct cma *cma = cma_from_kobj(kobj);
+
+ return sysfs_emit(buf, "%llu\n",
+ atomic64_read(&cma->nr_pages_succeeded));
+}
+CMA_ATTR_RO(alloc_pages_success);
+
+static ssize_t alloc_pages_fail_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ struct cma *cma = cma_from_kobj(kobj);
+
+ return sysfs_emit(buf, "%llu\n", atomic64_read(&cma->nr_pages_failed));
+}
+CMA_ATTR_RO(alloc_pages_fail);
+
+static void cma_kobj_release(struct kobject *kobj)
+{
+ struct cma *cma = cma_from_kobj(kobj);
+ struct cma_kobject *cma_kobj = cma->cma_kobj;
+
+ kfree(cma_kobj);
+ cma->cma_kobj = NULL;
+}
+
+static struct attribute *cma_attrs[] = {
+ &alloc_pages_success_attr.attr,
+ &alloc_pages_fail_attr.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(cma);
+
+static struct kobj_type cma_ktype = {
+ .release = cma_kobj_release,
+ .sysfs_ops = &kobj_sysfs_ops,
+ .default_groups = cma_groups,
+};
+
+static int __init cma_sysfs_init(void)
+{
+ struct kobject *cma_kobj_root;
+ struct cma_kobject *cma_kobj;
+ struct cma *cma;
+ int i, err;
+
+ cma_kobj_root = kobject_create_and_add("cma", mm_kobj);
+ if (!cma_kobj_root)
+ return -ENOMEM;
+
+ for (i = 0; i < cma_area_count; i++) {
+ cma_kobj = kzalloc(sizeof(*cma_kobj), GFP_KERNEL);
+ if (!cma_kobj) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ cma = &cma_areas[i];
+ cma->cma_kobj = cma_kobj;
+ cma_kobj->cma = cma;
+ err = kobject_init_and_add(&cma_kobj->kobj, &cma_ktype,
+ cma_kobj_root, "%s", cma->name);
+ if (err) {
+ kobject_put(&cma_kobj->kobj);
+ goto out;
+ }
+ }
+
+ return 0;
+out:
+ while (--i >= 0) {
+ cma = &cma_areas[i];
+ kobject_put(&cma->cma_kobj->kobj);
+ }
+ kobject_put(cma_kobj_root);
+
+ return err;
+}
+subsys_initcall(cma_sysfs_init);