From patchwork Mon Feb 8 18:01:42 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Minchan Kim X-Patchwork-Id: 12076175 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=-16.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 5C8F6C4332B for ; Mon, 8 Feb 2021 18:01:54 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D172A64E8F for ; Mon, 8 Feb 2021 18:01:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D172A64E8F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 483386B0006; Mon, 8 Feb 2021 13:01:53 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 431566B006C; Mon, 8 Feb 2021 13:01:53 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2ACC76B006E; Mon, 8 Feb 2021 13:01:53 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0116.hostedemail.com [216.40.44.116]) by kanga.kvack.org (Postfix) with ESMTP id 13D916B0006 for ; Mon, 8 Feb 2021 13:01:53 -0500 (EST) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id BE60518375314 for ; Mon, 8 Feb 2021 18:01:52 +0000 (UTC) X-FDA: 77795868864.20.play01_310910c27600 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin20.hostedemail.com (Postfix) with ESMTP id 46453180AA927 for ; Mon, 8 Feb 2021 18:01:49 +0000 (UTC) X-HE-Tag: play01_310910c27600 X-Filterd-Recvd-Size: 11288 Received: from mail-pf1-f169.google.com (mail-pf1-f169.google.com [209.85.210.169]) by imf15.hostedemail.com (Postfix) with ESMTP for ; Mon, 8 Feb 2021 18:01:48 +0000 (UTC) Received: by mail-pf1-f169.google.com with SMTP id q20so10200092pfu.8 for ; Mon, 08 Feb 2021 10:01:48 -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=Axjgr30iSBj/jYLiUjQfNQM9hvuQRpjGLmsQRdX6JxI=; b=seYS+I6SK2b5fNaK8u1KNHAVzvc05cGZ8+oaRMHTwOFXr7ORGxoXfBrSxn0gjVc/l5 ci3MPRnxW+CwLMBJHIEFeHmRYcW9DYojrPZb1TgCwDFUd0ubZa0Hl0gI7DwKLC24tjLU Do+0bAurjeK2AssZjKEkBZcRzg5s30+of8gi9fvRIoKOwudif9zAUY/h5wVAa4URYR6r CgWrDTDNI73ue5d0lSOhMb7zYO+wgd0tO6WjCCqPSs2q2GOxoLsS7aNh1HYgdxlhpLnS HIt0aJrse+IkCNd1jFIGr4Pf0Poyk36v2hpt6ubcXOBIOhI6rNtuMlWE3okniFpxgOHD 2ffA== 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=Axjgr30iSBj/jYLiUjQfNQM9hvuQRpjGLmsQRdX6JxI=; b=IqkDNTlswx93s8h/NFFbqzfZywASWbue8zOFGUS7cgv1+a90P0USJErF2uVZGij3x3 mbFLntdlly8M7aVJMk/OGeuRVioNBk1He+f767weP3fzqs6bz51QI0I9LLoMwYMT0/Bg YrF1U4Yid4aQn0PrFMHxQJCfpz1olGSRx1j75J4XAJEu5WV63n9/X85qonujqYpHF4e+ nsO2I6TWP4mG54nWIgqgbVZLBGDsAYwYPgtUF5iapsvX+X64Ri+9+gHh1ww8Upfv6rdm VNT4jSDa/1m//hA3fhRqBkwsZGbwbm2HoFssUqOTL8zjlqdrcZZAlYBu0FI6b7NAOt9C ynrw== X-Gm-Message-State: AOAM53398+7h0fGYjeMF1m7bTur581le9bu664i9h7OQTvMU82ejuQX7 O2HlKaFq87JHxJft7z+RpPc= X-Google-Smtp-Source: ABdhPJyQbBS/HSt882T8RyMS/L/LlMa/zs6yXhnHWkk6j8xXk4XRmlUS3EUr6qKX0Ccxx42mkN2nzQ== X-Received: by 2002:a63:d506:: with SMTP id c6mr18002404pgg.77.1612807307722; Mon, 08 Feb 2021 10:01:47 -0800 (PST) Received: from bbox-1.mtv.corp.google.com ([2620:15c:211:201:1557:50ce:fb7a:a325]) by smtp.gmail.com with ESMTPSA id 25sm3820539pfj.120.2021.02.08.10.01.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 08 Feb 2021 10:01:46 -0800 (PST) From: Minchan Kim To: Andrew Morton Cc: linux-mm , LKML , gregkh@linuxfoundation.org, surenb@google.com, joaodias@google.com, jhubbard@nvidia.com, willy@infradead.org, Minchan Kim Subject: [PATCH v2] mm: cma: support sysfs Date: Mon, 8 Feb 2021 10:01:42 -0800 Message-Id: <20210208180142.2765456-1-minchan@kernel.org> X-Mailer: git-send-email 2.30.0.478.g8a0d178c01-goog MIME-Version: 1.0 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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 for the CMA and exposes stats below to keep monitor for telemetric in the system. * the number of CMA page allocation attempts * the number of CMA page allocation failures With those per-CMA statistics, we could know how CMA allocadtion failure rate for each usecases. e.g.) /sys/kernel/mm/cma/WIFI/cma_alloc_pages_[attempt|fail] /sys/kernel/mm/cma/SENSOR/cma_alloc_pages_[attempt|fail] /sys/kernel/mm/cma/BLUETOOTH/cma_alloc_pages_[attempt|fail] Signed-off-by: Minchan Kim --- 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..68bdcc8c7681 --- /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 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/ directory + + - cma_alloc_pages_attempt + - cma_alloc_pages_fail + +What: /sys/kernel/mm/cma//cma_alloc_pages_attempt +Date: Feb 2021 +Contact: Minchan Kim +Description: + the number of pages CMA API tried to allocate + +What: /sys/kernel/mm/cma//cma_alloc_pages_fail +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..0ae764e5b1a8 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..0611202d6e7d 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(cma, count); pr_debug("%s(): returned %p\n", __func__, page); return page; diff --git a/mm/cma.h b/mm/cma.h index 42ae082cb067..49a8ceddd9e8 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_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 +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(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(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..1f6b9f785825 --- /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_attempt += count; + spin_unlock(&cma->stat->lock); +} + +void cma_sysfs_fail(struct cma *cma, size_t count) +{ + spin_lock(&cma->stat->lock); + 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_pages_attempt_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_attempt); +} +CMA_ATTR_RO(cma_alloc_pages_attempt); + +static ssize_t cma_alloc_pages_fail_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_fail); +} +CMA_ATTR_RO(cma_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_pages_attempt_attr.attr, + &cma_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 = 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);