mm: cma: support sysfs

Message ID	20210203155001.4121868-1-minchan@kernel.org (mailing list archive)
State	New, archived
Headers	show Return-Path: <SRS0=hDF9=HF=kvack.org=owner-linux-mm@kernel.org> DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A613264E93 From: Minchan Kim <minchan@kernel.org> To: Andrew Morton <akpm@linux-foundation.org> Cc: gregkh@linuxfoundation.org, surenb@google.com, joaodias@google.com, LKML <linux-kernel@vger.kernel.org>, linux-mm <linux-mm@kvack.org>, Minchan Kim <minchan@kernel.org> Subject: [PATCH] mm: cma: support sysfs Date: Wed, 3 Feb 2021 07:50:01 -0800 Message-Id: <20210203155001.4121868-1-minchan@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org Precedence: bulk
Series	mm: cma: support sysfs \| expand mm: cma: support sysfs

diff --git a/Documentation/ABI/testing/sysfs-kernel-mm-cma b/Documentation/ABI/testing/sysfs-kernel-mm-cma new file mode 100644 index 000000000000..2a43c0aacc39 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-kernel-mm-cma @@ -0,0 +1,39 @@ +What: /sys/kernel/mm/cma/ +Date: Feb 2021 +Contact: Minchan Kim <minchan@kernel.org> +Description: + /sys/kernel/mm/cma/ contains a number of subdirectories by + cma-heap name. The subdirectory contains a number of files + to represent cma allocation statistics. + + There are number of files under + /sys/kernel/mm/cma/<cma-heap-name> directory + + - cma_alloc_attempt + - cma_alloc_fail + - alloc_pages_attempt + - alloc_pages_fail + +What: /sys/kernel/mm/cma/<cma-heap-name>/cma_alloc_attempt +Date: Feb 2021 +Contact: Minchan Kim <minchan@kernel.org> +Description: + the number of cma_alloc API attempted + +What: /sys/kernel/mm/cma/<cma-heap-name>/cma_alloc_fail +Date: Feb 2021 +Contact: Minchan Kim <minchan@kernel.org> +Description: + the number of CMA_alloc API failed + +What: /sys/kernel/mm/cma/<cma-heap-name>/alloc_pages_attempt +Date: Feb 2021 +Contact: Minchan Kim <minchan@kernel.org> +Description: + the number of pages CMA API tried 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/include/linux/cma.h b/include/linux/cma.h index 217999c8a762..71a28a5bb54e 100644 --- a/include/linux/cma.h +++ b/include/linux/cma.h @@ -49,4 +49,5 @@ extern struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align, extern bool cma_release(struct cma *cma, const struct page *pages, unsigned int count); extern int cma_for_each_area(int (*it)(struct cma *cma, void *data), void *data); + #endif diff --git a/mm/Makefile b/mm/Makefile index b2a564eec27f..9c2c81ce3894 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -106,6 +106,7 @@ obj-$(CONFIG_ZSMALLOC) += zsmalloc.o obj-$(CONFIG_Z3FOLD) += z3fold.o obj-$(CONFIG_GENERIC_EARLY_IOREMAP) += early_ioremap.o obj-$(CONFIG_CMA) += cma.o +obj-$(CONFIG_SYSFS) += cma_sysfs.o obj-$(CONFIG_MEMORY_BALLOON) += balloon_compaction.o obj-$(CONFIG_PAGE_EXTENSION) += page_ext.o obj-$(CONFIG_CMA_DEBUGFS) += cma_debug.o diff --git a/mm/cma.c b/mm/cma.c index 0ba69cd16aeb..a25068b9d012 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -448,9 +448,10 @@ struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align, offset = cma_bitmap_aligned_offset(cma, align); bitmap_maxno = cma_bitmap_maxno(cma); bitmap_count = cma_bitmap_pages_to_bits(cma, count); + cma_sysfs_alloc_count(cma, count); if (bitmap_count > bitmap_maxno) - return NULL; + goto out; for (;;) { mutex_lock(&cma->lock); @@ -505,6 +506,9 @@ struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align, __func__, count, ret); cma_debug_show_areas(cma); } +out: + if (!page) + cma_sysfs_fail(cma, count); pr_debug("%s(): returned %p\n", __func__, page); return page; diff --git a/mm/cma.h b/mm/cma.h index 42ae082cb067..e7e31012b44e 100644 --- a/mm/cma.h +++ b/mm/cma.h @@ -3,6 +3,16 @@ #define __MM_CMA_H__ #include <linux/debugfs.h> +#include <linux/kobject.h> + +struct cma_stat { + spinlock_t lock; + unsigned long alloc_attempt; /* the number of CMA allocation attempts */ + unsigned long alloc_fail; /* the number of CMA allocation failures */ + unsigned long pages_attempt; /* the number of CMA page allocation attempts */ + unsigned long pages_fail; /* the number of CMA page allocation failures */ + struct kobject kobj; +}; struct cma { unsigned long base_pfn; @@ -16,6 +26,9 @@ struct cma { struct debugfs_u32_array dfs_bitmap; #endif char name[CMA_MAX_NAME]; +#ifdef CONFIG_SYSFS + struct cma_stat *stat; +#endif }; extern struct cma cma_areas[MAX_CMA_AREAS]; @@ -26,4 +39,11 @@ static inline unsigned long cma_bitmap_maxno(struct cma *cma) return cma->count >> cma->order_per_bit; } +#ifdef CONFIG_SYSFS +void cma_sysfs_alloc_count(struct cma *cma, size_t count); +void cma_sysfs_fail(struct cma *cma, size_t count); +#else +static void cma_sysfs_alloc_count(struct cma *cma, size_t count) {}; +static void cma_sysfs_fail(struct cma *cma, size_t count) {}; +#endif #endif diff --git a/mm/cma_sysfs.c b/mm/cma_sysfs.c new file mode 100644 index 000000000000..66df292cd6ca --- /dev/null +++ b/mm/cma_sysfs.c @@ -0,0 +1,143 @@ +// 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" + +void cma_sysfs_alloc_count(struct cma *cma, size_t count) +{ + spin_lock(&cma->stat->lock); + cma->stat->alloc_attempt++; + cma->stat->pages_attempt += count; + spin_unlock(&cma->stat->lock); +} + +void cma_sysfs_fail(struct cma *cma, size_t count) +{ + spin_lock(&cma->stat->lock); + cma->stat->alloc_fail++; + cma->stat->pages_fail += count; + spin_unlock(&cma->stat->lock); +} + +#define CMA_ATTR_RO(_name) \ + static struct kobj_attribute _name##_attr = __ATTR_RO(_name) + +static struct kobject *cma_kobj; + +static ssize_t cma_alloc_attempt_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + unsigned long val; + struct cma_stat *stat = container_of(kobj, struct cma_stat, kobj); + + val = stat->alloc_attempt; + + return sysfs_emit(buf, "%lu\n", val); +} +CMA_ATTR_RO(cma_alloc_attempt); + +static ssize_t cma_alloc_fail_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + unsigned long val; + struct cma_stat *stat = container_of(kobj, struct cma_stat, kobj); + + val = stat->alloc_fail; + + return sysfs_emit(buf, "%lu\n", val); +} +CMA_ATTR_RO(cma_alloc_fail); + +static ssize_t alloc_pages_attempt_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + unsigned long val; + struct cma_stat *stat = container_of(kobj, struct cma_stat, kobj); + + val = stat->pages_attempt; + + return sysfs_emit(buf, "%lu\n", val); +} +CMA_ATTR_RO(alloc_pages_attempt); + +static ssize_t alloc_pages_fail_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + unsigned long val; + struct cma_stat *stat = container_of(kobj, struct cma_stat, kobj); + + val = stat->pages_fail; + + return sysfs_emit(buf, "%lu\n", val); +} +CMA_ATTR_RO(alloc_pages_fail); + +static void cma_kobj_release(struct kobject *kobj) +{ + struct cma_stat *stat = container_of(kobj, struct cma_stat, kobj); + + kfree(stat); +} + +static struct attribute *cma_attrs[] = { + &cma_alloc_attempt_attr.attr, + &cma_alloc_fail_attr.attr, + &alloc_pages_attempt_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) +{ + int i; + struct cma *cma; + struct cma_stat *stat; + + cma_kobj = kobject_create_and_add("cma", mm_kobj); + if (!cma_kobj) { + pr_err("failed to create cma kobject\n"); + return -ENOMEM; + } + + for (i = 0; i < cma_area_count; i++) { + cma = &cma_areas[i]; + stat = kzalloc(sizeof(*stat), GFP_KERNEL); + if (!stat) + goto out; + + cma->stat = stat; + spin_lock_init(&stat->lock); + if (kobject_init_and_add(&stat->kobj, &cma_ktype, + cma_kobj, "%s", cma->name)) { + kobject_put(&stat->kobj); + goto out; + } + } + + return 0; +out: + while (--i >= 0) { + cma = &cma_areas[i]; + kobject_put(&cma->stat->kobj); + } + + kobject_put(cma_kobj); + + return -ENOMEM; +} +subsys_initcall(cma_sysfs_init);

mm: cma: support sysfs

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