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=-15.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 3203DC433E0 for ; Mon, 25 Jan 2021 06:43:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0200A207B6 for ; Mon, 25 Jan 2021 06:43:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726866AbhAYGnJ (ORCPT ); Mon, 25 Jan 2021 01:43:09 -0500 Received: from m42-8.mailgun.net ([69.72.42.8]:42155 "EHLO m42-8.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726854AbhAYGXK (ORCPT ); Mon, 25 Jan 2021 01:23:10 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1611555761; h=Content-Transfer-Encoding: Content-Type: In-Reply-To: MIME-Version: Date: Message-ID: From: References: Cc: To: Subject: Sender; bh=E2wieLkm3quzxVzVDryNDRhLZIPJN0rRhfDkI5MXjz4=; b=Bc9q42HCTupCjIza+M6o0GFPQz2XBx72LAQgsbjU5/QmDpNdrj9oUb0Id4as5gHMWPEC6nTl SKsZERcWulL8QLTJOw02eMAUv0hsvqCOi8ub2rVGj8ymhSceLVTuKJM50F/EHhn21AOYtC5p hNTdMa2Jyub+XPcey7xqYPegH+A= X-Mailgun-Sending-Ip: 69.72.42.8 X-Mailgun-Sid: WyI0MWYwYSIsICJsaW51eC1rZXJuZWxAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n07.prod.us-east-1.postgun.com with SMTP id 600e63962c36b2106db6ee6c (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Mon, 25 Jan 2021 06:22:14 GMT Sender: faiyazm=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 82191C43461; Mon, 25 Jan 2021 06:22:13 +0000 (UTC) Received: from [192.168.43.20] (unknown [157.48.198.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: faiyazm) by smtp.codeaurora.org (Postfix) with ESMTPSA id F194BC433CA; Mon, 25 Jan 2021 06:22:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org F194BC433CA Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=fail smtp.mailfrom=faiyazm@codeaurora.org Subject: Re: [PATCH] mm: slub: Convert sys slab alloc_calls, free_calls to bin attribute To: Vlastimil Babka , cl@linux.com, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: vinmenon@codeaurora.org References: <1610443287-23933-1-git-send-email-faiyazm@codeaurora.org> From: Faiyaz Mohammed Message-ID: Date: Mon, 25 Jan 2021 11:52:04 +0530 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/13/2021 9:35 PM, Vlastimil Babka wrote: > On 1/12/21 10:21 AM, Faiyaz Mohammed wrote: >> Reading the sys slab alloc_calls, free_calls returns the available object >> owners, but the size of this file is limited to PAGE_SIZE >> because of the limitation of sysfs attributes, it is returning the >> partial owner info, which is not sufficient to debug/account the slab >> memory and alloc_calls output is not matching with /proc/slabinfo. >> >> To remove the PAGE_SIZE limitation converted the sys slab >> alloc_calls, free_calls to bin attribute. >> >> Signed-off-by: Faiyaz Mohammed >> --- >> mm/slub.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++-------------- >> 1 file changed, 47 insertions(+), 14 deletions(-) >> >> diff --git a/mm/slub.c b/mm/slub.c >> index b52384e..8744e5ec 100644 >> --- a/mm/slub.c >> +++ b/mm/slub.c >> @@ -4710,13 +4710,14 @@ static void process_slab(struct loc_track *t, struct kmem_cache *s, >> } >> >> static int list_locations(struct kmem_cache *s, char *buf, >> - enum track_item alloc) >> + loff_t offset, enum track_item alloc) >> { >> int len = 0; >> unsigned long i; >> struct loc_track t = { 0, 0, NULL }; >> int node; >> struct kmem_cache_node *n; >> + static unsigned int previous_read_count; > > Hmm static? What about parallel reads from different files? I guess you'll have > to somehow employ the offset parameter here and it won't be pretty, because you > are still printing free text and not some fixed-size binary chunks where seeking > is simple. > Also it's wasteful to to repeat the data gathering for each pritned page, you'd > need a mechanism that allows holding private data between printing out the > pages. If bin_attribute doesn't have that, you'd need e.g. seq_file which we use > for /proc/pid/(s)maps etc. > Sorry for the delay response, I was on vacation. I will get back to you on seq_file feasibility. >> unsigned long *map = bitmap_alloc(oo_objects(s->max), GFP_KERNEL); > > This line doesn't exist since 90e9f6a66c78f in v5.6-rc1, is the patch based on > an old kernel? > >> if (!map || !alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location), >> @@ -4742,11 +4743,9 @@ static int list_locations(struct kmem_cache *s, char *buf, >> spin_unlock_irqrestore(&n->list_lock, flags); >> } >> >> - for (i = 0; i < t.count; i++) { >> + for (i = previous_read_count; i < t.count; i++) { >> struct location *l = &t.loc[i]; >> >> - if (len > PAGE_SIZE - KSYM_SYMBOL_LEN - 100) >> - break; >> len += sprintf(buf + len, "%7ld ", l->count); >> >> if (l->addr) >> @@ -4784,12 +4783,20 @@ static int list_locations(struct kmem_cache *s, char *buf, >> nodemask_pr_args(&l->nodes)); >> >> len += sprintf(buf + len, "\n"); >> + >> + if (len > PAGE_SIZE - KSYM_SYMBOL_LEN - 100) { >> + previous_read_count = i + 1; >> + break; >> + } >> } >> >> + if ((offset != 0) && ((i >= t.count) || (previous_read_count > t.count))) { >> + previous_read_count = 0; >> + len = 0; >> + } else if (!t.count) >> + len += sprintf(buf, "No data\n"); >> free_loc_track(&t); >> bitmap_free(map); >> - if (!t.count) >> - len += sprintf(buf, "No data\n"); >> return len; >> } >> >> @@ -5180,6 +5187,7 @@ static int any_slab_objects(struct kmem_cache *s) >> >> struct slab_attribute { >> struct attribute attr; >> + struct bin_attribute bin_attr; >> ssize_t (*show)(struct kmem_cache *s, char *buf); >> ssize_t (*store)(struct kmem_cache *s, const char *x, size_t count); >> }; >> @@ -5192,6 +5200,12 @@ struct slab_attribute { >> static struct slab_attribute _name##_attr = \ >> __ATTR(_name, 0600, _name##_show, _name##_store) >> >> +#define SLAB_BIN_ATTR_RO(_name) \ >> + static struct slab_attribute _name##_attr = { \ >> + .bin_attr = \ >> + __BIN_ATTR_RO(_name, 0) \ >> + } \ >> + >> static ssize_t slab_size_show(struct kmem_cache *s, char *buf) >> { >> return sprintf(buf, "%u\n", s->size); >> @@ -5535,21 +5549,33 @@ static ssize_t validate_store(struct kmem_cache *s, >> } >> SLAB_ATTR(validate); >> >> -static ssize_t alloc_calls_show(struct kmem_cache *s, char *buf) >> +static ssize_t alloc_calls_read(struct file *filp, struct kobject *kobj, >> + struct bin_attribute *bin_attr, char *buf, >> + loff_t offset, size_t count) >> { >> + struct kmem_cache *s; >> + >> + s = to_slab(kobj); >> if (!(s->flags & SLAB_STORE_USER)) >> return -ENOSYS; >> - return list_locations(s, buf, TRACK_ALLOC); >> + >> + return list_locations(s, buf, offset, TRACK_ALLOC); >> } >> -SLAB_ATTR_RO(alloc_calls); >> +SLAB_BIN_ATTR_RO(alloc_calls); >> >> -static ssize_t free_calls_show(struct kmem_cache *s, char *buf) >> +static ssize_t free_calls_read(struct file *filp, struct kobject *kobj, >> + struct bin_attribute *bin_attr, char *buf, >> + loff_t offset, size_t count) >> { >> + struct kmem_cache *s; >> + >> + s = to_slab(kobj); >> if (!(s->flags & SLAB_STORE_USER)) >> return -ENOSYS; >> - return list_locations(s, buf, TRACK_FREE); >> + >> + return list_locations(s, buf, offset, TRACK_FREE); >> } >> -SLAB_ATTR_RO(free_calls); >> +SLAB_BIN_ATTR_RO(free_calls); >> #endif /* CONFIG_SLUB_DEBUG */ >> >> #ifdef CONFIG_FAILSLAB >> @@ -5694,6 +5720,14 @@ STAT_ATTR(CPU_PARTIAL_NODE, cpu_partial_node); >> STAT_ATTR(CPU_PARTIAL_DRAIN, cpu_partial_drain); >> #endif /* CONFIG_SLUB_STATS */ >> >> + >> +static struct bin_attribute *slab_bin_attrs[] = { >> +#ifdef CONFIG_SLUB_DEBUG >> + &alloc_calls_attr.bin_attr, >> + &free_calls_attr.bin_attr, >> +#endif >> +}; >> + >> static struct attribute *slab_attrs[] = { >> &slab_size_attr.attr, >> &object_size_attr.attr, >> @@ -5722,8 +5756,6 @@ static struct attribute *slab_attrs[] = { >> &poison_attr.attr, >> &store_user_attr.attr, >> &validate_attr.attr, >> - &alloc_calls_attr.attr, >> - &free_calls_attr.attr, >> #endif >> #ifdef CONFIG_ZONE_DMA >> &cache_dma_attr.attr, >> @@ -5769,6 +5801,7 @@ static struct attribute *slab_attrs[] = { >> >> static const struct attribute_group slab_attr_group = { >> .attrs = slab_attrs, >> + .bin_attrs = slab_bin_attrs, >> }; >> >> static ssize_t slab_attr_show(struct kobject *kobj, >> >