From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D3A3EC433DB for ; Wed, 10 Feb 2021 07:56:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8A50664DA1 for ; Wed, 10 Feb 2021 07:56:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233263AbhBJH4B (ORCPT ); Wed, 10 Feb 2021 02:56:01 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41606 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233145AbhBJHzy (ORCPT ); Wed, 10 Feb 2021 02:55:54 -0500 Received: from mail-pj1-x1036.google.com (mail-pj1-x1036.google.com [IPv6:2607:f8b0:4864:20::1036]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 09E6CC061574 for ; Tue, 9 Feb 2021 23:55:14 -0800 (PST) Received: by mail-pj1-x1036.google.com with SMTP id lw17so2566946pjb.0 for ; Tue, 09 Feb 2021 23:55:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=nw99JP24pMTZQDcP6TCv8VsAJTTPXi9uTgiJMgze2TM=; b=O9c11yRXgVXrh2bTLWlO/cKWNEhmQMETGHVfuXTGf+sh4mimwyrQ8wr+NO2MrzFc/m x7t2pqDsObjMqYJdAM5FNZ2a3ixNJVWHY/o4y6c6bANh3qmTkFESUai7u04SoDlZiGNv Qn9dheACQmsrdSYWQeSJvprVyN7RszvQ/xhO/Q/DvesFRPB7QVNrm+ammkP6BfIEMR7w ha1vigtirrjUBy5oZ8IJqYIpdki0XGfTXbeydamSbJqIO/pzguSvCMAKii1NqkJshPdl nGZYkEI+TVe3pdpSFMa3NbOSGm34lD72tDmhqLGhRxEgGO6rS7qh/VQ0jCry269vkM8H NGqw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :mime-version:content-transfer-encoding; bh=nw99JP24pMTZQDcP6TCv8VsAJTTPXi9uTgiJMgze2TM=; b=tKXMOLNECDroBrH5oK+0DJhYhwL8HJj/txdhBopc/7IpLFu01K54XHW/DKfpeQ6Ba7 4UHjuyEpFMdGyCr8WlQP/7WJTmSBtkV7mwhmCPnaEYD9r9FH2ETrrs5jCIH0G0fTD8a6 Q7xx7sTUUuJMxirPUSCnff+CwTuvDfQhzlYRpsND4+tQu7RsLiXWUkE8QYVd0tQLqA2d eDrT2CUoLdHVYVtTiBk+uijQ+GLBj3yFgwBRITwVipK4eltQUmOqdzhl2ca36K5RRI8u Cy+dy/YiZnTnkUnLdU7o9X6DOAOiuky1lCg3/h/nB4ZZtqNg/++Qan+jJ2cYCAXDmeVF 2gBA== X-Gm-Message-State: AOAM5310LhEARrGJcTPJ/KFOZdpYlsu0YEsyzJjbWL6EjOj8Su/eci8Q MJw7zefb2RuAyQrURXUwCrI= X-Google-Smtp-Source: ABdhPJwWgjWD3E25gYYNTUZyg7FrpbIB8tgW3ehqn+03QTPP1T11eZ6FogywoeKX6fmA4AFjAIgnzA== X-Received: by 2002:a17:90b:1081:: with SMTP id gj1mr2006061pjb.231.1612943713591; Tue, 09 Feb 2021 23:55:13 -0800 (PST) Received: from bbox-1.mtv.corp.google.com ([2620:15c:211:201:d107:fbfb:a7c8:913e]) by smtp.gmail.com with ESMTPSA id i7sm1239259pjx.13.2021.02.09.23.55.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 09 Feb 2021 23:55:12 -0800 (PST) Sender: Minchan Kim From: Minchan Kim To: Andrew Morton Cc: jhubbard@nvidia.com, willy@infradead.org, gregkh@linuxfoundation.org, surenb@google.com, joaodias@google.com, LKML , linux-mm , Minchan Kim Subject: [PATCH v3] mm: cma: support sysfs Date: Tue, 9 Feb 2021 23:55:09 -0800 Message-Id: <20210210075509.3788729-1-minchan@kernel.org> X-Mailer: git-send-email 2.30.0.478.g8a0d178c01-goog MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Since CMA is getting used more widely, it's more important to keep monitoring CMA statistics for system health since it's directly related to user experience. This patch introduces sysfs statistics for CMA, in order to provide some basic monitoring of the CMA allocator. * the number of CMA page allocation attempts * the number of CMA page allocation failures These two values allow the user to calcuate the allocation failure rate for each CMA area. e.g.) /sys/kernel/mm/cma/WIFI/cma_alloc_pages_[attempts|fails] /sys/kernel/mm/cma/SENSOR/cma_alloc_pages_[attempts|fails] /sys/kernel/mm/cma/BLUETOOTH/cma_alloc_pages_[attempts|fails] Signed-off-by: Minchan Kim --- >From v2 - https://lore.kernel.org/linux-mm/20210208180142.2765456-1-minchan@kernel.org/ * sysfs doc and description modification - jhubbard >From v1 - https://lore.kernel.org/linux-mm/20210203155001.4121868-1-minchan@kernel.org/ * fix sysfs build and refactoring - willy * rename and drop some attributes - jhubbard Documentation/ABI/testing/sysfs-kernel-mm-cma | 25 ++++ mm/Kconfig | 7 ++ mm/Makefile | 1 + mm/cma.c | 6 +- mm/cma.h | 18 +++ mm/cma_sysfs.c | 114 ++++++++++++++++++ 6 files changed, 170 insertions(+), 1 deletion(-) create mode 100644 Documentation/ABI/testing/sysfs-kernel-mm-cma create mode 100644 mm/cma_sysfs.c diff --git a/Documentation/ABI/testing/sysfs-kernel-mm-cma b/Documentation/ABI/testing/sysfs-kernel-mm-cma new file mode 100644 index 000000000000..f518af819cee --- /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 +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/ directory) contains the + following items: + + cma_alloc_pages_attempts + cma_alloc_pages_fails + +What: /sys/kernel/mm/cma//cma_alloc_pages_attempts +Date: Feb 2021 +Contact: Minchan Kim +Description: + the number of pages CMA API tried to allocate + +What: /sys/kernel/mm/cma//cma_alloc_pages_fails +Date: Feb 2021 +Contact: Minchan Kim +Description: + the number of pages CMA API failed to allocate diff --git a/mm/Kconfig b/mm/Kconfig index ec35bf406439..ad7e9c065657 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -513,6 +513,13 @@ 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 b2a564eec27f..e10c14300191 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 23d4a97c834a..b42ccafc71e5 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -447,9 +447,10 @@ 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); @@ -504,6 +505,9 @@ 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_count(cma, count); pr_debug("%s(): returned %p\n", __func__, page); return page; diff --git a/mm/cma.h b/mm/cma.h index 42ae082cb067..24a1d61eabc7 100644 --- a/mm/cma.h +++ b/mm/cma.h @@ -3,6 +3,14 @@ #define __MM_CMA_H__ #include +#include + +struct cma_stat { + spinlock_t lock; + unsigned long pages_attempts; /* the number of CMA page allocation attempts */ + unsigned long pages_fails; /* the number of CMA page allocation failures */ + struct kobject kobj; +}; struct cma { unsigned long base_pfn; @@ -16,6 +24,9 @@ struct cma { struct debugfs_u32_array dfs_bitmap; #endif char name[CMA_MAX_NAME]; +#ifdef CONFIG_CMA_SYSFS + struct cma_stat *stat; +#endif }; extern struct cma cma_areas[MAX_CMA_AREAS]; @@ -26,4 +37,11 @@ static inline unsigned long cma_bitmap_maxno(struct cma *cma) return cma->count >> cma->order_per_bit; } +#ifdef CONFIG_CMA_SYSFS +void cma_sysfs_alloc_count(struct cma *cma, size_t count); +void cma_sysfs_fail_count(struct cma *cma, size_t count); +#else +static inline void cma_sysfs_alloc_count(struct cma *cma, size_t count) {}; +static inline void cma_sysfs_fail_count(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..d281bf95a614 --- /dev/null +++ b/mm/cma_sysfs.c @@ -0,0 +1,114 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * CMA SysFS Interface + * + * Copyright (c) 2021 Minchan Kim + */ + +#include +#include +#include + +#include "cma.h" + +static struct cma_stat *cma_stats; + +void cma_sysfs_alloc_count(struct cma *cma, size_t count) +{ + spin_lock(&cma->stat->lock); + cma->stat->pages_attempts += count; + spin_unlock(&cma->stat->lock); +} + +void cma_sysfs_fail_count(struct cma *cma, size_t count) +{ + spin_lock(&cma->stat->lock); + cma->stat->pages_fails += 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_pages_attempts_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + struct cma_stat *stat = container_of(kobj, struct cma_stat, kobj); + + return sysfs_emit(buf, "%lu\n", stat->pages_attempts); +} +CMA_ATTR_RO(cma_alloc_pages_attempts); + +static ssize_t cma_alloc_pages_fails_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + struct cma_stat *stat = container_of(kobj, struct cma_stat, kobj); + + return sysfs_emit(buf, "%lu\n", stat->pages_fails); +} +CMA_ATTR_RO(cma_alloc_pages_fails); + +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_pages_attempts_attr.attr, + &cma_alloc_pages_fails_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 = 0; + struct cma *cma; + + cma_kobj = kobject_create_and_add("cma", mm_kobj); + if (!cma_kobj) { + pr_err("failed to create cma kobject\n"); + return -ENOMEM; + } + + cma_stats = kzalloc(array_size(sizeof(struct cma_stat), + cma_area_count), GFP_KERNEL); + if (!cma_stats) { + pr_err("failed to create cma_stats\n"); + goto out; + } + + do { + cma = &cma_areas[i]; + cma->stat = &cma_stats[i]; + spin_lock_init(&cma->stat->lock); + if (kobject_init_and_add(&cma->stat->kobj, &cma_ktype, + cma_kobj, "%s", cma->name)) { + kobject_put(&cma->stat->kobj); + goto out; + } + } while (++i < cma_area_count); + + return 0; +out: + while (--i >= 0) { + cma = &cma_areas[i]; + kobject_put(&cma->stat->kobj); + } + + kfree(cma_stats); + kobject_put(cma_kobj); + + return -ENOMEM; +} +subsys_initcall(cma_sysfs_init); -- 2.30.0.478.g8a0d178c01-goog