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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 64FD6EE6456 for ; Fri, 15 Sep 2023 11:00:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234065AbjIOLBB (ORCPT ); Fri, 15 Sep 2023 07:01:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59598 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234325AbjIOLA7 (ORCPT ); Fri, 15 Sep 2023 07:00:59 -0400 Received: from mail-ej1-x649.google.com (mail-ej1-x649.google.com [IPv6:2a00:1450:4864:20::649]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 51E7B2736 for ; Fri, 15 Sep 2023 04:00:11 -0700 (PDT) Received: by mail-ej1-x649.google.com with SMTP id a640c23a62f3a-94a355c9028so141573466b.3 for ; Fri, 15 Sep 2023 04:00:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1694775609; x=1695380409; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=Xv8bl1gghcslEiMH0/FhgvPpwPOagI6elAD3nLRWX2k=; b=S2p93F7A0wqiuJDV2GRyCDi4nQ/GWf5rYiMWy293ffMZgTknAV9VtkFjanCFblpjeZ Vz8riOrDUxMru8/Xd+jpL+9x03lPexD3tetyF6nW+ZLbmerLobIp+mZKD17m9CNfUpsE MOqVfSqBBVEwpWiGN4oAFbfSgW2oDtnN6GHD4WjvkPcaimIqVdD4ytihCT2228jmRTAH 4jruLV64m/j0Dw4HwPpSfLEXH1kKv5/XByh5i9fjp1NAjcewXlYamwpJh3hR/KRt2IZJ WL363SQmgT7XUMl8Xni4TtoUSQoQYLnnhqDNxZLxAbv/ueK4lNbA92kVd7zi0iRu4Gm1 YX5g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1694775609; x=1695380409; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=Xv8bl1gghcslEiMH0/FhgvPpwPOagI6elAD3nLRWX2k=; b=BOuBjdmKeEQT3SWd8jryUp96wkUCj1dvhQfNzPZR+nswc3vIfYsb/yxOwKalVhX9av vNqcRQTrUUxBt1jX2RXcn27Ne0F2/Vv5If5S1/GJuI1KwylPvsXOgZE3uyJy3cPdILxS iaNF7U5C4GWc6R4G6gfF/7FSnzPSRwNtP6bzn9KLwOkfIlLgDsuiE07v5n46aF6hGf5f C05QU0T4EQvKt1v4lcRSecoanhVacbb7HnlQD0/1v7ZaV9ZdDtIi+yuLmk6/xcgmklUI ++iG8DjHE/cA+4a2Vqc6Oc0F+fO9uP2WBOx9LfLx2wj8VWA6bD9YFZp7fOyPaGCJuLyu OHLQ== X-Gm-Message-State: AOJu0Yzr6HgfuAAiRRornLvW5A2jK1wMWEBqhRG6BgyOKBx0EjrPdb6E Vjo74qkF6gu0/XYThXV4UuX5hJR7lg4H7zA/TA== X-Google-Smtp-Source: AGHT+IEynAr2SnY1fMJiDuLoEg0/d2a8kjbFH3ONSC9J81629RSdKiVLHnan7ER1f/DyQsRkv3eYGMXRY5zwIxc8BQ== X-Received: from mr-cloudtop2.c.googlers.com ([fda3:e722:ac3:cc00:31:98fb:c0a8:2a6]) (user=matteorizzo job=sendgmr) by 2002:a17:907:71d7:b0:9ad:c478:586b with SMTP id zw23-20020a17090771d700b009adc478586bmr6329ejb.13.1694775609336; Fri, 15 Sep 2023 04:00:09 -0700 (PDT) Date: Fri, 15 Sep 2023 10:59:31 +0000 In-Reply-To: <20230915105933.495735-1-matteorizzo@google.com> Mime-Version: 1.0 References: <20230915105933.495735-1-matteorizzo@google.com> X-Mailer: git-send-email 2.42.0.459.ge4e396fd5e-goog Message-ID: <20230915105933.495735-13-matteorizzo@google.com> Subject: [RFC PATCH 12/14] mm/slub: introduce the deallocated_pages sysfs attribute From: Matteo Rizzo To: cl@linux.com, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, akpm@linux-foundation.org, vbabka@suse.cz, roman.gushchin@linux.dev, 42.hyeyoo@gmail.com, keescook@chromium.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-hardening@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, corbet@lwn.net, luto@kernel.org, peterz@infradead.org Cc: jannh@google.com, matteorizzo@google.com, evn@google.com, poprdi@google.com, jordyzomer@google.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org From: Jann Horn When SLAB_VIRTUAL is enabled this new sysfs attribute tracks the number of slab pages whose physical memory has been reclaimed but whose virtual memory is still allocated to a kmem_cache. Signed-off-by: Jann Horn Co-developed-by: Matteo Rizzo Signed-off-by: Matteo Rizzo --- include/linux/slub_def.h | 4 +++- mm/slub.c | 18 ++++++++++++++++++ 2 files changed, 21 insertions(+), 1 deletion(-) diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h index 693e9bb34edc..eea402d849da 100644 --- a/include/linux/slub_def.h +++ b/include/linux/slub_def.h @@ -88,7 +88,7 @@ struct kmem_cache_cpu { */ struct kmem_cache_virtual { #ifdef CONFIG_SLAB_VIRTUAL - /* Protects freed_slabs and freed_slabs_min */ + /* Protects freed_slabs, freed_slabs_min, and nr_free_pages */ spinlock_t freed_slabs_lock; /* * Slabs on this list have virtual memory of size oo allocated to them @@ -97,6 +97,8 @@ struct kmem_cache_virtual { struct list_head freed_slabs; /* Same as freed_slabs but with memory of size min */ struct list_head freed_slabs_min; + /* Number of slab pages which got freed */ + unsigned long nr_freed_pages; #endif }; diff --git a/mm/slub.c b/mm/slub.c index 66ae60cdadaf..0f7f5bf0b174 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -2110,6 +2110,8 @@ static struct slab *get_free_slab(struct kmem_cache *s, if (likely(slab)) { list_del(&slab->slab_list); + WRITE_ONCE(s->virtual.nr_freed_pages, + s->virtual.nr_freed_pages - (1UL << slab_order(slab))); spin_unlock_irqrestore(&s->virtual.freed_slabs_lock, flags); return slab; @@ -2158,6 +2160,8 @@ static struct slab *alloc_slab_page(struct kmem_cache *s, /* Rollback: put the struct slab back. */ spin_lock_irqsave(&s->virtual.freed_slabs_lock, flags); list_add(&slab->slab_list, freed_slabs); + WRITE_ONCE(s->virtual.nr_freed_pages, + s->virtual.nr_freed_pages + (1UL << slab_order(slab))); spin_unlock_irqrestore(&s->virtual.freed_slabs_lock, flags); return NULL; @@ -2438,6 +2442,8 @@ static void slub_tlbflush_worker(struct kthread_work *work) WARN_ON(oo_order(slab->oo) != oo_order(s->min)); list_add(&slab->slab_list, &s->virtual.freed_slabs_min); } + WRITE_ONCE(s->virtual.nr_freed_pages, s->virtual.nr_freed_pages + + (1UL << slab_order(slab))); spin_unlock(&s->virtual.freed_slabs_lock); } spin_unlock_irqrestore(&slub_kworker_lock, irq_flags); @@ -4924,6 +4930,7 @@ static inline void slab_virtual_open(struct kmem_cache *s) spin_lock_init(&s->virtual.freed_slabs_lock); INIT_LIST_HEAD(&s->virtual.freed_slabs); INIT_LIST_HEAD(&s->virtual.freed_slabs_min); + s->virtual.nr_freed_pages = 0; #endif } @@ -6098,6 +6105,14 @@ static ssize_t objects_partial_show(struct kmem_cache *s, char *buf) } SLAB_ATTR_RO(objects_partial); +#ifdef CONFIG_SLAB_VIRTUAL +static ssize_t deallocated_pages_show(struct kmem_cache *s, char *buf) +{ + return sysfs_emit(buf, "%lu\n", READ_ONCE(s->virtual.nr_freed_pages)); +} +SLAB_ATTR_RO(deallocated_pages); +#endif /* CONFIG_SLAB_VIRTUAL */ + static ssize_t slabs_cpu_partial_show(struct kmem_cache *s, char *buf) { int objects = 0; @@ -6424,6 +6439,9 @@ static struct attribute *slab_attrs[] = { &min_partial_attr.attr, &cpu_partial_attr.attr, &objects_partial_attr.attr, +#ifdef CONFIG_SLAB_VIRTUAL + &deallocated_pages_attr.attr, +#endif &partial_attr.attr, &cpu_slabs_attr.attr, &ctor_attr.attr, -- 2.42.0.459.ge4e396fd5e-goog