[v7] mm: cma: support sysfs

Message ID	20210324205503.2132082-1-minchan@kernel.org (mailing list archive)
State	New, archived
Headers	show Return-Path: <SRS0=u5hr=IW=kvack.org=owner-linux-mm@kernel.org> DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 76134619B4 From: Minchan Kim <minchan@kernel.org> To: Andrew Morton <akpm@linux-foundation.org> Cc: linux-mm <linux-mm@kvack.org>, LKML <linux-kernel@vger.kernel.org>, gregkh@linuxfoundation.org, surenb@google.com, joaodias@google.com, jhubbard@nvidia.com, willy@infradead.org, digetx@gmail.com, Minchan Kim <minchan@kernel.org>, Colin Ian King <colin.king@canonical.com> Subject: [PATCH v7] mm: cma: support sysfs Date: Wed, 24 Mar 2021 13:55:03 -0700 Message-Id: <20210324205503.2132082-1-minchan@kernel.org> MIME-Version: 1.0 Received-SPF: none (gmail.com>: No applicable sender policy available) receiver=imf07; identity=mailfrom; envelope-from="<minchan.kim@gmail.com>"; helo=mail-pf1-f169.google.com; client-ip=209.85.210.169 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org Precedence: bulk
Series	[v7] mm: cma: support sysfs \| expand [v7] 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..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 23a0e3c98ff0..3823a2314256 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -524,6 +524,13 @@ 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 9e284dba50ef..788c5ce5c0ef 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -112,6 +112,7 @@ 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 0361e289c31a..08c45157911a 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -507,10 +507,14 @@ 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 42ae082cb067..37b9b7858c8e 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 cma *cma; + struct kobject kobj; +}; 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..73463be08df7 --- /dev/null +++ b/mm/cma_sysfs.c @@ -0,0 +1,116 @@ +// 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_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); +} + +#define CMA_ATTR_RO(_name) \ + static struct kobj_attribute _name##_attr = __ATTR_RO(_name) + +static inline struct cma *cma_from_kobj(struct kobject *kobj) +{ + struct cma_kobject *cma_kobj = container_of(kobj, struct cma_kobject, + kobj); + struct cma *cma = cma_kobj->cma; + + return 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);

[v7] mm: cma: support sysfs

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