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Harding" X-Patchwork-Id: 10949889 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AF49F17D2 for ; Mon, 20 May 2019 05:41:21 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9E4142022C for ; Mon, 20 May 2019 05:41:21 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 920E92863C; Mon, 20 May 2019 05:41:21 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B2B5628635 for ; Mon, 20 May 2019 05:41:20 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B28156B0006; Mon, 20 May 2019 01:41:19 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id AD8796B0007; Mon, 20 May 2019 01:41:19 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9A0766B0008; Mon, 20 May 2019 01:41:19 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from mail-qt1-f197.google.com (mail-qt1-f197.google.com [209.85.160.197]) by kanga.kvack.org (Postfix) with ESMTP id 77CB56B0006 for ; Mon, 20 May 2019 01:41:19 -0400 (EDT) Received: by mail-qt1-f197.google.com with SMTP id b46so13231713qte.6 for ; Sun, 19 May 2019 22:41:19 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:dkim-signature:from:to:cc:subject:date :message-id:in-reply-to:references:mime-version :content-transfer-encoding; bh=/Io00D878lZ0GkrFvR4yMjAJgpoguE22uvDOPIw7E14=; b=b3JPw1l+fplU4XB+KWq0MAcCz2/KmfKYPdhn8JjWqSdRf9XCTaQyQY3GTNkOsrgbLF NO9fKSxnwlRM3/Kn/FUitvwm99Aoobh7+uaiSzKoRsOriebotN2M1uPULhXxd1kD+qca 1i/Tv0/rSVaR5s/Hx+ZIb0vnKmN+IFi9L/OAiJdBhYQcQEK/r/KhL2G53w6qtJoX6oUK AeXnZ81wO06S4HR3T+bn5DuwWvPTGvlRNrntUEOngrL91VWu0FKXMY2PENhuDxntDeMk 5mnjjChIARjB4+eH0Mu2YHgcOLu+vW/SHmjXOgpti+s/aUzXNgzSgM/ioG0/g2ddSgFv ROHg== X-Gm-Message-State: APjAAAWJFHNyoyiEZLF/UufDcq7U8nUDtfB/hWc05bYqm6kEU369wDar VU26SKcGQM7TFUnSJazTUdMX0xZFQbQbplvtnRYZ1L2yE1/vOAdHU3/DwVn4PcJcDg0zkabKH90 MKyWwhkSlA6NvjbKrs6s61gw/cvichAIRwFyaHjYWjaEWnmriXFr+tuftZEDXbfE= X-Received: by 2002:ac8:60d4:: with SMTP id i20mr54222886qtm.376.1558330879235; Sun, 19 May 2019 22:41:19 -0700 (PDT) X-Google-Smtp-Source: APXvYqwFfsfIlUpDyKgbxl4C/umH5SbsIfoOnSXNsZoYgO8HAfml9YiNH0/eaQcqA9wcTr/0CvEz X-Received: by 2002:ac8:60d4:: with SMTP id i20mr54222812qtm.376.1558330877783; Sun, 19 May 2019 22:41:17 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1558330877; cv=none; d=google.com; s=arc-20160816; b=YgLwU5OjIOoqSXJOg0JblmCVZYoLjv7dPDk16yWqS0fj9r+WkTZXSm5pmbBMYY8lEA Z6E2MLxxjcWoYiudToyXfEdVUbrjRivSXHPJsNRGeWuWsFd3CM3+LJzCinrlwdsus6GV m1qakL36FxQc9KESs5SaTx7O+cn3CBZFFOrt2VK9SlOVbjkvVXbFSYT+YPAYiQO23lLM lu9RIO1/fhVAlRruRO1uSsZKG8Ciyqyz1C/pBigsyptq+9LjTR/h8QPma2lDeLr+6RUQ Q7jjLBWIagsKdUTnlb5I97DrhvZLNswQCKlVMhEAdOTGeMKlxJCYIXz6ibIUGkmpBCiH GKxQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:dkim-signature; bh=/Io00D878lZ0GkrFvR4yMjAJgpoguE22uvDOPIw7E14=; b=aDkgPYZ/NE5HdI3Iqv7Z316zuRuXRAslEhC/vjOx4lnUXO7WT0T7dQyMFhiqNQWzok OyrJanCDi9j69Wb5YroDT7mfUwdekLuPmIU8mbyDhkxcV+8phQNbN6ua29+sNOICxnVd baewnR/TbHXLlzuHiGsoPKT9ZLrps4rhqY2vcBCEjmWbyQ9658HLqXJvIWC1Otn6e1zb 2bxigwFdQ+pJgRkmnKtT+gdx/MCtD7oiHoM6IRt9HwXWCecBzHJbcQoB0AhWhX0rh8mg Az7klJNlPgFVrnebx6u4RLUk45THRTXvxqSBPpJqlJkkRTidtb9ygh4fW2wMjNwDopvf fXBg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@messagingengine.com header.s=fm2 header.b=RReBq3uf; spf=softfail (google.com: domain of transitioning tobin@kernel.org does not designate 66.111.4.230 as permitted sender) smtp.mailfrom=tobin@kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from new4-smtp.messagingengine.com (new4-smtp.messagingengine.com. [66.111.4.230]) by mx.google.com with ESMTPS id o185si8033101qkd.256.2019.05.19.22.41.17 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 19 May 2019 22:41:17 -0700 (PDT) Received-SPF: softfail (google.com: domain of transitioning tobin@kernel.org does not designate 66.111.4.230 as permitted sender) client-ip=66.111.4.230; Authentication-Results: mx.google.com; dkim=pass header.i=@messagingengine.com header.s=fm2 header.b=RReBq3uf; spf=softfail (google.com: domain of transitioning tobin@kernel.org does not designate 66.111.4.230 as permitted sender) smtp.mailfrom=tobin@kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from compute3.internal (compute3.nyi.internal [10.202.2.43]) by mailnew.nyi.internal (Postfix) with ESMTP id 7A3DBF012; Mon, 20 May 2019 01:41:17 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute3.internal (MEProxy); Mon, 20 May 2019 01:41:17 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:date:from :in-reply-to:message-id:mime-version:references:subject:to :x-me-proxy:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s= fm2; bh=/Io00D878lZ0GkrFvR4yMjAJgpoguE22uvDOPIw7E14=; b=RReBq3uf YVGO/bPlbhRNtkSgs5+ZAFxsCb7IKnF5f3Rf5w1KQvTyRNBb4iZV3/7EyRM/y4aF TIa6n2zBMITaGCDSCdkr0Lt57+834/eRjm84VBIi18qnpyj7nwlDUKKk/UUKSqj+ yJaJNkRi1v2TtIo2MlYkBebXQnms6oN2IzcgS4BR3zbYX4jE7nvTrKf1yuTlMes3 kq4kW81wSvZREvoGW4tUzpUTiNqBSxYCX/88L50/n40kwi0BqJ2nEMWXBj055zad Rmg7JmST1XKtFdx9hkiGo9Jqui2mQVHUgNInfs19FqQjdCgJUhm9bkNVSf4PcKfO l7uGUx9O0xuRiw== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduuddruddtjedguddtudcutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfgh necuuegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmd enucfjughrpefhvffufffkofgjfhgggfestdekredtredttdenucfhrhhomhepfdfvohgs ihhnucevrdcujfgrrhguihhnghdfuceothhosghinheskhgvrhhnvghlrdhorhhgqeenuc fkphepuddvgedrudeiledrudehiedrvddtfeenucfrrghrrghmpehmrghilhhfrhhomhep thhosghinheskhgvrhhnvghlrdhorhhgnecuvehluhhsthgvrhfuihiivgeptd X-ME-Proxy: Received: from eros.localdomain (124-169-156-203.dyn.iinet.net.au [124.169.156.203]) by mail.messagingengine.com (Postfix) with ESMTPA id 4B96580062; Mon, 20 May 2019 01:41:10 -0400 (EDT) From: "Tobin C. Harding" To: Andrew Morton , Matthew Wilcox Cc: "Tobin C. Harding" , Roman Gushchin , Alexander Viro , Christoph Hellwig , Pekka Enberg , David Rientjes , Joonsoo Kim , Christopher Lameter , Miklos Szeredi , Andreas Dilger , Waiman Long , Tycho Andersen , Theodore Ts'o , Andi Kleen , David Chinner , Nick Piggin , Rik van Riel , Hugh Dickins , Jonathan Corbet , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RFC PATCH v5 01/16] slub: Add isolate() and migrate() methods Date: Mon, 20 May 2019 15:40:02 +1000 Message-Id: <20190520054017.32299-2-tobin@kernel.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190520054017.32299-1-tobin@kernel.org> References: <20190520054017.32299-1-tobin@kernel.org> 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: X-Virus-Scanned: ClamAV using ClamSMTP Add the two methods needed for moving objects and enable the display of the callbacks via the /sys/kernel/slab interface. Add documentation explaining the use of these methods and the prototypes for slab.h. Add functions to setup the callbacks method for a slab cache. Add empty functions for SLAB/SLOB. The API is generic so it could be theoretically implemented for these allocators as well. Change sysfs 'ctor' field to be 'ops' to contain all the callback operations defined for a slab cache. Display the existing 'ctor' callback in the ops fields contents along with 'isolate' and 'migrate' callbacks. Co-developed-by: Christoph Lameter Signed-off-by: Tobin C. Harding Reviewed-by: Roman Gushchin --- include/linux/slab.h | 70 ++++++++++++++++++++++++++++++++++++++++ include/linux/slub_def.h | 3 ++ mm/slub.c | 59 +++++++++++++++++++++++++++++---- 3 files changed, 126 insertions(+), 6 deletions(-) diff --git a/include/linux/slab.h b/include/linux/slab.h index 9449b19c5f10..886fc130334d 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -154,6 +154,76 @@ void memcg_create_kmem_cache(struct mem_cgroup *, struct kmem_cache *); void memcg_deactivate_kmem_caches(struct mem_cgroup *); void memcg_destroy_kmem_caches(struct mem_cgroup *); +/* + * Function prototypes passed to kmem_cache_setup_mobility() to enable + * mobile objects and targeted reclaim in slab caches. + */ + +/** + * typedef kmem_cache_isolate_func - Object migration callback function. + * @s: The cache we are working on. + * @ptr: Pointer to an array of pointers to the objects to isolate. + * @nr: Number of objects in @ptr array. + * + * The purpose of kmem_cache_isolate_func() is to pin each object so that + * they cannot be freed until kmem_cache_migrate_func() has processed + * them. This may be accomplished by increasing the refcount or setting + * a flag. + * + * The object pointer array passed is also passed to + * kmem_cache_migrate_func(). The function may remove objects from the + * array by setting pointers to %NULL. This is useful if we can + * determine that an object is being freed because + * kmem_cache_isolate_func() was called when the subsystem was calling + * kmem_cache_free(). In that case it is not necessary to increase the + * refcount or specially mark the object because the release of the slab + * lock will lead to the immediate freeing of the object. + * + * Context: Called with locks held so that the slab objects cannot be + * freed. We are in an atomic context and no slab operations + * may be performed. + * Return: A pointer that is passed to the migrate function. If any + * objects cannot be touched at this point then the pointer may + * indicate a failure and then the migration function can simply + * remove the references that were already obtained. The private + * data could be used to track the objects that were already pinned. + */ +typedef void *kmem_cache_isolate_func(struct kmem_cache *s, void **ptr, int nr); + +/** + * typedef kmem_cache_migrate_func - Object migration callback function. + * @s: The cache we are working on. + * @ptr: Pointer to an array of pointers to the objects to migrate. + * @nr: Number of objects in @ptr array. + * @node: The NUMA node where the object should be allocated. + * @private: The pointer returned by kmem_cache_isolate_func(). + * + * This function is responsible for migrating objects. Typically, for + * each object in the input array you will want to allocate an new + * object, copy the original object, update any pointers, and free the + * old object. + * + * After this function returns all pointers to the old object should now + * point to the new object. + * + * Context: Called with no locks held and interrupts enabled. Sleeping + * is possible. Any operation may be performed. + */ +typedef void kmem_cache_migrate_func(struct kmem_cache *s, void **ptr, + int nr, int node, void *private); + +/* + * kmem_cache_setup_mobility() is used to setup callbacks for a slab cache. + */ +#ifdef CONFIG_SLUB +void kmem_cache_setup_mobility(struct kmem_cache *, kmem_cache_isolate_func, + kmem_cache_migrate_func); +#else +static inline void +kmem_cache_setup_mobility(struct kmem_cache *s, kmem_cache_isolate_func isolate, + kmem_cache_migrate_func migrate) {} +#endif + /* * Please use this macro to create slab caches. Simply specify the * name of the structure and maybe some flags that are listed above. diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h index d2153789bd9f..2879a2f5f8eb 100644 --- a/include/linux/slub_def.h +++ b/include/linux/slub_def.h @@ -99,6 +99,9 @@ struct kmem_cache { gfp_t allocflags; /* gfp flags to use on each alloc */ int refcount; /* Refcount for slab cache destroy */ void (*ctor)(void *); + kmem_cache_isolate_func *isolate; + kmem_cache_migrate_func *migrate; + unsigned int inuse; /* Offset to metadata */ unsigned int align; /* Alignment */ unsigned int red_left_pad; /* Left redzone padding size */ diff --git a/mm/slub.c b/mm/slub.c index cd04dbd2b5d0..1c380a2bc78a 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -4317,6 +4317,33 @@ int __kmem_cache_create(struct kmem_cache *s, slab_flags_t flags) return err; } +void kmem_cache_setup_mobility(struct kmem_cache *s, + kmem_cache_isolate_func isolate, + kmem_cache_migrate_func migrate) +{ + /* + * Mobile objects must have a ctor otherwise the object may be + * in an undefined state on allocation. Since the object may + * need to be inspected by the migration function at any time + * after allocation we must ensure that the object always has a + * defined state. + */ + if (!s->ctor) { + pr_err("%s: require constructor to setup mobility\n", s->name); + return; + } + + s->isolate = isolate; + s->migrate = migrate; + + /* + * Sadly serialization requirements currently mean that we have + * to disable fast cmpxchg based processing. + */ + s->flags &= ~__CMPXCHG_DOUBLE; +} +EXPORT_SYMBOL(kmem_cache_setup_mobility); + void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, unsigned long caller) { struct kmem_cache *s; @@ -5001,13 +5028,33 @@ static ssize_t cpu_partial_store(struct kmem_cache *s, const char *buf, } SLAB_ATTR(cpu_partial); -static ssize_t ctor_show(struct kmem_cache *s, char *buf) +static int op_show(char *buf, const char *txt, unsigned long addr) { - if (!s->ctor) - return 0; - return sprintf(buf, "%pS\n", s->ctor); + int x = 0; + + x += sprintf(buf, "%s : ", txt); + x += sprint_symbol(buf + x, addr); + x += sprintf(buf + x, "\n"); + + return x; +} + +static ssize_t ops_show(struct kmem_cache *s, char *buf) +{ + int x = 0; + + if (s->ctor) + x += op_show(buf + x, "ctor", (unsigned long)s->ctor); + + if (s->isolate) + x += op_show(buf + x, "isolate", (unsigned long)s->isolate); + + if (s->migrate) + x += op_show(buf + x, "migrate", (unsigned long)s->migrate); + + return x; } -SLAB_ATTR_RO(ctor); +SLAB_ATTR_RO(ops); static ssize_t aliases_show(struct kmem_cache *s, char *buf) { @@ -5420,7 +5467,7 @@ static struct attribute *slab_attrs[] = { &objects_partial_attr.attr, &partial_attr.attr, &cpu_slabs_attr.attr, - &ctor_attr.attr, + &ops_attr.attr, &aliases_attr.attr, &align_attr.attr, &hwcache_align_attr.attr,