From patchwork Thu May 6 10:22:03 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Faiyaz Mohammed X-Patchwork-Id: 12241977 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=-16.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 11DB0C433B4 for ; Thu, 6 May 2021 10:22:34 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 662B9611AC for ; Thu, 6 May 2021 10:22:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 662B9611AC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id D3B4C6B006C; Thu, 6 May 2021 06:22:32 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CEB1C6B006E; Thu, 6 May 2021 06:22:32 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AF1546B0070; Thu, 6 May 2021 06:22:32 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0102.hostedemail.com [216.40.44.102]) by kanga.kvack.org (Postfix) with ESMTP id 8AFBC6B006C for ; Thu, 6 May 2021 06:22:32 -0400 (EDT) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 3CDA48249980 for ; Thu, 6 May 2021 10:22:32 +0000 (UTC) X-FDA: 78110416944.25.6D2AED4 Received: from m43-7.mailgun.net (m43-7.mailgun.net [69.72.43.7]) by imf28.hostedemail.com (Postfix) with ESMTP id 983AE2000266 for ; Thu, 6 May 2021 10:22:29 +0000 (UTC) DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1620296551; h=Message-Id: Date: Subject: Cc: To: From: Sender; bh=4HeYf0SOVpwKNRj2HiaMr+axZWRmAnYkslP2OQu5Y7w=; b=A25ZSgNddGliCVS1yS3AxR3KURezvBDOxXtDI+ibPDWbHyoBpfIxwDwPlIZ1xzy0JOmJ3QhL 2QesPG1+NBGIWq6iPCY/lgwvYgH86WOPnx4FQe5Pr86Cu2CcG7SEzc063cWHUmEuu5TBhIXr NavHCKl7HbuG1TydSJtfw6UDEf8= X-Mailgun-Sending-Ip: 69.72.43.7 X-Mailgun-Sid: WyIwY2Q3OCIsICJsaW51eC1tbUBrdmFjay5vcmciLCAiYmU5ZTRhIl0= Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n04.prod.us-west-2.postgun.com with SMTP id 6093c35af34440a9d4b4a7fb (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Thu, 06 May 2021 10:22:18 GMT Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 62591C43217; Thu, 6 May 2021 10:22:18 +0000 (UTC) Received: from faiyazm-linux.qualcomm.com (unknown [202.46.22.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: faiyazm) by smtp.codeaurora.org (Postfix) with ESMTPSA id 93FA9C43460; Thu, 6 May 2021 10:22:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 93FA9C43460 From: Faiyaz Mohammed To: cl@linux.com, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, akpm@linux-foundation.org, vbabka@suse.cz, linux-mm@kvack.org, linux-kernel@vger.kernel.org, glittao@gmail.com Cc: vinmenon@codeaurora.org, Faiyaz Mohammed Subject: [PATCH v5] mm: slub: move sysfs slab alloc/free interfaces to debugfs Date: Thu, 6 May 2021 15:52:03 +0530 Message-Id: <1620296523-21922-1-git-send-email-faiyazm@codeaurora.org> X-Mailer: git-send-email 2.7.4 Authentication-Results: imf28.hostedemail.com; dkim=pass header.d=mg.codeaurora.org header.s=smtp header.b=A25ZSgNd; spf=pass (imf28.hostedemail.com: domain of bounce@mg.codeaurora.org designates 69.72.43.7 as permitted sender) smtp.mailfrom=bounce@mg.codeaurora.org; dmarc=none X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 983AE2000266 X-Stat-Signature: axhqzwfgoi4au3smj183mwj8nznx9y5b Received-SPF: none (mg.codeaurora.org>: No applicable sender policy available) receiver=imf28; identity=mailfrom; envelope-from=""; helo=m43-7.mailgun.net; client-ip=69.72.43.7 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1620296549-931896 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: alloc_calls and free_calls implementation in sysfs have two issues, one is PAGE_SIZE limitiation of sysfs and other is it does not adhere to "one value per file" rule. To overcome this issues, move the alloc_calls and free_calls implemeation to debugfs. Rename the alloc_calls/free_calls to alloc_traces/free_traces, to be inline with what it does. Signed-off-by: Faiyaz Mohammed Reported-by: kernel test robot Reported-by: kernel test robot Reported-by: kernel test robot Reported-by: Dan Carpenter --- include/linux/slub_def.h | 10 ++ mm/slab_common.c | 9 ++ mm/slub.c | 362 ++++++++++++++++++++++++++++++++++++----------- 3 files changed, 299 insertions(+), 82 deletions(-) diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h index dcde82a..f8c268d 100644 --- a/include/linux/slub_def.h +++ b/include/linux/slub_def.h @@ -110,6 +110,9 @@ struct kmem_cache { #ifdef CONFIG_SYSFS struct kobject kobj; /* For sysfs */ #endif +#ifdef CONFIG_SLUB_DEBUG + struct dentry *slab_cache_dentry; +#endif #ifdef CONFIG_SLAB_FREELIST_HARDENED unsigned long random; #endif @@ -159,6 +162,13 @@ static inline void sysfs_slab_release(struct kmem_cache *s) } #endif +#ifdef CONFIG_DEBUG_FS +void debugfs_slab_release(struct kmem_cache *); +#else +static inline void debugfs_slab_release(struct kmem_cache *s) +{ +} +#endif void object_err(struct kmem_cache *s, struct page *page, u8 *object, char *reason); diff --git a/mm/slab_common.c b/mm/slab_common.c index f8833d3..f3afe6b 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -445,6 +445,9 @@ static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work) #else slab_kmem_cache_release(s); #endif +#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_SLUB) + debugfs_slab_release(s); +#endif } } @@ -462,6 +465,9 @@ static int shutdown_cache(struct kmem_cache *s) #ifdef SLAB_SUPPORTS_SYSFS sysfs_slab_unlink(s); #endif +#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_SLUB) + debugfs_slab_release(s); +#endif list_add_tail(&s->list, &slab_caches_to_rcu_destroy); schedule_work(&slab_caches_to_rcu_destroy_work); } else { @@ -472,6 +478,9 @@ static int shutdown_cache(struct kmem_cache *s) #else slab_kmem_cache_release(s); #endif +#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_SLUB) + debugfs_slab_release(s); +#endif } return 0; diff --git a/mm/slub.c b/mm/slub.c index 68123b2..a5347f1 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -36,6 +36,7 @@ #include #include +#include #include #include "internal.h" @@ -225,6 +226,15 @@ static inline int sysfs_slab_alias(struct kmem_cache *s, const char *p) { return 0; } #endif +#ifdef CONFIG_DEBUG_FS +static void debugfs_slab_add(struct kmem_cache *); +static int debugfs_slab_alias(struct kmem_cache *, const char *); +#else +static inline void debugfs_slab_add(struct kmem_cache *s) { } +static inline int debugfs_slab_alias(struct kmem_cache *s, const char *p) + { return 0; } +#endif + static inline void stat(const struct kmem_cache *s, enum stat_item si) { #ifdef CONFIG_SLUB_STATS @@ -4533,6 +4543,8 @@ __kmem_cache_alias(const char *name, unsigned int size, unsigned int align, s->refcount--; s = NULL; } + + debugfs_slab_alias(s, name); } return s; @@ -4554,6 +4566,8 @@ int __kmem_cache_create(struct kmem_cache *s, slab_flags_t flags) if (err) __kmem_cache_release(s); + debugfs_slab_add(s); + return err; } @@ -4694,6 +4708,8 @@ static long validate_slab_cache(struct kmem_cache *s) return count; } + +#ifdef CONFIG_DEBUG_FS /* * Generate lists of code addresses where slabcache objects are allocated * and freed. @@ -4717,6 +4733,9 @@ struct loc_track { struct location *loc; }; +static struct dentry *slab_debugfs_root; +struct loc_track t = { 0, 0, NULL }; + static void free_loc_track(struct loc_track *t) { if (t->max) @@ -4833,82 +4852,7 @@ static void process_slab(struct loc_track *t, struct kmem_cache *s, add_location(t, s, get_track(s, p, alloc)); put_map(map); } - -static int list_locations(struct kmem_cache *s, char *buf, - enum track_item alloc) -{ - int len = 0; - unsigned long i; - struct loc_track t = { 0, 0, NULL }; - int node; - struct kmem_cache_node *n; - - if (!alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location), - GFP_KERNEL)) { - return sysfs_emit(buf, "Out of memory\n"); - } - /* Push back cpu slabs */ - flush_all(s); - - for_each_kmem_cache_node(s, node, n) { - unsigned long flags; - struct page *page; - - if (!atomic_long_read(&n->nr_slabs)) - continue; - - spin_lock_irqsave(&n->list_lock, flags); - list_for_each_entry(page, &n->partial, slab_list) - process_slab(&t, s, page, alloc); - list_for_each_entry(page, &n->full, slab_list) - process_slab(&t, s, page, alloc); - spin_unlock_irqrestore(&n->list_lock, flags); - } - - for (i = 0; i < t.count; i++) { - struct location *l = &t.loc[i]; - - len += sysfs_emit_at(buf, len, "%7ld ", l->count); - - if (l->addr) - len += sysfs_emit_at(buf, len, "%pS", (void *)l->addr); - else - len += sysfs_emit_at(buf, len, ""); - - if (l->sum_time != l->min_time) - len += sysfs_emit_at(buf, len, " age=%ld/%ld/%ld", - l->min_time, - (long)div_u64(l->sum_time, - l->count), - l->max_time); - else - len += sysfs_emit_at(buf, len, " age=%ld", l->min_time); - - if (l->min_pid != l->max_pid) - len += sysfs_emit_at(buf, len, " pid=%ld-%ld", - l->min_pid, l->max_pid); - else - len += sysfs_emit_at(buf, len, " pid=%ld", - l->min_pid); - - if (num_online_cpus() > 1 && - !cpumask_empty(to_cpumask(l->cpus))) - len += sysfs_emit_at(buf, len, " cpus=%*pbl", - cpumask_pr_args(to_cpumask(l->cpus))); - - if (nr_online_nodes > 1 && !nodes_empty(l->nodes)) - len += sysfs_emit_at(buf, len, " nodes=%*pbl", - nodemask_pr_args(&l->nodes)); - - len += sysfs_emit_at(buf, len, "\n"); - } - - free_loc_track(&t); - if (!t.count) - len += sysfs_emit_at(buf, len, "No data\n"); - - return len; -} +#endif /* CONFIG_DEBUG_FS */ #endif /* CONFIG_SLUB_DEBUG */ #ifdef SLUB_RESILIENCY_TEST @@ -5360,17 +5304,25 @@ SLAB_ATTR(validate); static ssize_t alloc_calls_show(struct kmem_cache *s, char *buf) { - if (!(s->flags & SLAB_STORE_USER)) - return -ENOSYS; - return list_locations(s, buf, TRACK_ALLOC); + int len = 0; + + len += sprintf(buf + len, "Deprecated, use the equvalent under\n"); + len += sprintf(buf + len, "/sys/kernel/debug/slab/%s/alloc_traces\n", + s->name); + + return len; } SLAB_ATTR_RO(alloc_calls); static ssize_t free_calls_show(struct kmem_cache *s, char *buf) { - if (!(s->flags & SLAB_STORE_USER)) - return -ENOSYS; - return list_locations(s, buf, TRACK_FREE); + int len = 0; + + len += sprintf(buf + len, "Deprecated, use the equvalent under\n"); + len += sprintf(buf + len, "/sys/kernel/debug/slab/%s/free_traces\n", + s->name); + + return len; } SLAB_ATTR_RO(free_calls); #endif /* CONFIG_SLUB_DEBUG */ @@ -5826,6 +5778,252 @@ static int __init slab_sysfs_init(void) __initcall(slab_sysfs_init); #endif /* CONFIG_SYSFS */ +#if defined(CONFIG_SLUB_DEBUG) && defined(CONFIG_DEBUG_FS) +static int debugfs_slab_alias(struct kmem_cache *s, const char *name) +{ + struct saved_alias *al; + + if (slab_state == FULL) { + /* + * If we have a leftover link then remove it. + */ + debugfs_remove(s->slab_cache_dentry); + s->slab_cache_dentry = debugfs_create_symlink(name, slab_debugfs_root, NULL); + return IS_ERR(s->slab_cache_dentry); + } + + al = kmalloc(sizeof(struct saved_alias), GFP_KERNEL); + if (!al) + return -ENOMEM; + + al->s = s; + al->name = name; + al->next = alias_list; + alias_list = al; + return 0; +} + +static int slab_debugfs_show(struct seq_file *seq, void *v) +{ + + struct location *l; + unsigned int idx = *(unsigned int *)v; + + if (idx < t.count) { + l = &t.loc[idx]; + + seq_printf(seq, "%7ld ", l->count); + + if (l->addr) + seq_printf(seq, "%pS", (void *)l->addr); + else + seq_puts(seq, ""); + + if (l->sum_time != l->min_time) { + seq_printf(seq, " age=%ld/%ld/%ld", + l->min_time, + (long)div_u64(l->sum_time, l->count), + l->max_time); + } else + seq_printf(seq, " age=%ld", + l->min_time); + + if (l->min_pid != l->max_pid) + seq_printf(seq, " pid=%ld-%ld", + l->min_pid, l->max_pid); + else + seq_printf(seq, " pid=%ld", + l->min_pid); + + if (num_online_cpus() > 1 && + !cpumask_empty(to_cpumask(l->cpus))) + seq_printf(seq, " cpus=%*pbl", + cpumask_pr_args(to_cpumask(l->cpus))); + + if (nr_online_nodes > 1 && !nodes_empty(l->nodes)) + seq_printf(seq, " nodes=%*pbl", + nodemask_pr_args(&l->nodes)); + + seq_puts(seq, "\n"); + } + + if (t.count == 0) + seq_puts(seq, "No data\n"); + + return 0; +} + +static void slab_debugfs_stop(struct seq_file *seq, void *v) +{ + if (!v && t.max) { + free_loc_track(&t); + t.max = 0; + } +} + +static void *slab_debugfs_next(struct seq_file *seq, void *v, loff_t *ppos) +{ + loff_t *spos = v; + + if (*ppos < t.count) { + *spos = *spos + 1; + *ppos = *spos; + return spos; + } + + return NULL; +} + +static void *slab_debugfs_start(struct seq_file *seq, loff_t *ppos) +{ + struct kmem_cache_node *n; + struct kmem_cache *s; + enum track_item alloc; + int node; + loff_t *spos = kmalloc(sizeof(loff_t), GFP_KERNEL); + + s = seq->file->f_inode->i_private; + + if (!spos) + return NULL; + + if (!(s->flags & SLAB_STORE_USER)) + return ERR_PTR(-EOPNOTSUPP); + + if (*ppos == 0) { + + t.count = 0; + t.max = 0; + t.loc = NULL; + if (strcmp(seq->file->f_path.dentry->d_name.name, "alloc_traces") == 0) + alloc = TRACK_ALLOC; + else + alloc = TRACK_FREE; + + if (!alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location), + GFP_KERNEL)) { + seq_puts(seq, "Out of memory\n"); + return ERR_PTR(-ENOMEM); + } + /* Push back cpu slabs */ + flush_all(s); + + for_each_kmem_cache_node(s, node, n) { + unsigned long flags; + struct page *page; + + if (!atomic_long_read(&n->nr_slabs)) + continue; + + spin_lock_irqsave(&n->list_lock, flags); + list_for_each_entry(page, &n->partial, slab_list) + process_slab(&t, s, page, alloc); + list_for_each_entry(page, &n->full, slab_list) + process_slab(&t, s, page, alloc); + spin_unlock_irqrestore(&n->list_lock, flags); + } + } + + if (*ppos < t.count) { + *spos = *ppos; + return spos; + } + + kfree(spos); + return NULL; +} + +static const struct seq_operations slab_debugfs_sops = { + .start = slab_debugfs_start, + .next = slab_debugfs_next, + .stop = slab_debugfs_stop, + .show = slab_debugfs_show +}; +DEFINE_SEQ_ATTRIBUTE(slab_debugfs); + +static void debugfs_slab_add(struct kmem_cache *s) +{ + const char *name; + int unmergeable = slab_unmergeable(s); + + if (unlikely(!slab_debugfs_root)) + return; + + if (!unmergeable && disable_higher_order_debug && + (slub_debug & DEBUG_METADATA_FLAGS)) + unmergeable = 1; + + if (unmergeable) { + /* + * Slabcache can never be merged so we can use the name proper. + * This is typically the case for debug situations. In that + * case we can catch duplicate names easily. + */ + debugfs_remove_recursive(s->slab_cache_dentry); + name = s->name; + } else { + /* + * Create a unique name for the slab as a target + * for the symlinks. + */ + name = create_unique_id(s); + } + + s->slab_cache_dentry = debugfs_create_dir(name, slab_debugfs_root); + if (!IS_ERR(s->slab_cache_dentry)) { + debugfs_create_file("alloc_traces", 0400, + s->slab_cache_dentry, s, &slab_debugfs_fops); + + debugfs_create_file("free_traces", 0400, + s->slab_cache_dentry, s, &slab_debugfs_fops); + } + + if (!unmergeable) { + /* Setup first alias */ + debugfs_slab_alias(s, s->name); + } +} + +void debugfs_slab_release(struct kmem_cache *s) +{ + if (slab_state >= FULL) + debugfs_remove_recursive(s->slab_cache_dentry); +} + +static int __init slab_debugfs_init(void) +{ + struct kmem_cache *s; + int err; + + slab_debugfs_root = debugfs_create_dir("slab", NULL); + if (!IS_ERR(slab_debugfs_root)) { + + slab_state = FULL; + + list_for_each_entry(s, &slab_caches, list) + debugfs_slab_add(s); + } else { + pr_err("Cannot create slab debugfs.\n"); + return IS_ERR(slab_debugfs_root); + } + + while (alias_list) { + struct saved_alias *al = alias_list; + + alias_list = alias_list->next; + + err = debugfs_slab_alias(al->s, al->name); + if (err) + pr_err("SLUB: Unable to add boot slab alias %s to debugfs\n", + al->name); + kfree(al); + } + + return 0; + +} +__initcall(slab_debugfs_init); +#endif /* * The /proc/slabinfo ABI */