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Harding" X-Patchwork-Id: 10894941 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 93DC117E1 for ; Thu, 11 Apr 2019 01:35:51 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 883FF28979 for ; Thu, 11 Apr 2019 01:35:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 856B7289A9; Thu, 11 Apr 2019 01:35:51 +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=unavailable 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 B6F9F28832 for ; Thu, 11 Apr 2019 01:35:50 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9075C6B0006; Wed, 10 Apr 2019 21:35:49 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 8B6D86B0007; Wed, 10 Apr 2019 21:35:49 -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 77D6F6B0008; Wed, 10 Apr 2019 21:35:49 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from mail-qt1-f199.google.com (mail-qt1-f199.google.com [209.85.160.199]) by kanga.kvack.org (Postfix) with ESMTP id 53F5E6B0006 for ; Wed, 10 Apr 2019 21:35:49 -0400 (EDT) Received: by mail-qt1-f199.google.com with SMTP id z34so4122571qtz.14 for ; Wed, 10 Apr 2019 18:35:49 -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=ToWY0R45y8BHjmAdWxteY+oDuIkdik3lI8PSNGM4h2M=; b=LdgY0geuAtmU0a4FFBloeLMFn8nyhxPGq3WT/zbwqr4IbXJrmFctL479AeNwLJASPq zJkYPaIoBINjZAJvD/lgdI7aMWqJkJnzK9VxbMEK9YRUdyk5GjLMbYnqGSVZXMpnNlN8 g6tYAieh1ciEXRSR9CulpfWuT60DRgJK8XAZEumpcgNDOZXckJcAsjvo6DxounTajvyP UV1O/ke/uJJSLqUM7v6xTZnqhftPUJ5tX7NK6K4cMK1NdP3PfdOUFnffdCCeI+x/2oUR u3TWD6AdActVEsaQNJn2yfpviPzWUy76TsHiEWCkDfNZ7/RJGOyawIZWcHwsm9yxgxxR jA7w== X-Gm-Message-State: APjAAAVIebri3AnlXLZQ/65z9UpL45vCjSBoyJR00pIDYjYoakuUZW27 N2rkZPowQ8MXYrKf5KcSE3WSXxmEx2WjlRIk+4pZ8GOWJFqJ+qWxA7S1v5y4dFHhyJ6/YKmfzVk K0DqTZ3XoQUXbjNnIIUKYT6b991On3SZlKHcHQskAtNhzd0wB42HedWT1RFBx1fE= X-Received: by 2002:aed:2507:: with SMTP id v7mr39123466qtc.131.1554946549028; Wed, 10 Apr 2019 18:35:49 -0700 (PDT) X-Google-Smtp-Source: APXvYqzruZ/3TxbGilEYvWLhpGTue5VnbLgEGhH3ztX0KHqQUUdxYQ7O43ODRlE6b7RL0uc8edqV X-Received: by 2002:aed:2507:: with SMTP id v7mr39123395qtc.131.1554946547595; Wed, 10 Apr 2019 18:35:47 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1554946547; cv=none; d=google.com; s=arc-20160816; b=emvWeumJMZ4sjr9KY4qPPD9I8YUF7fdiOdcbBKwOk+C9J+F/LA3LMaZ20TNqkKIiG1 fN70ch7AgvxnG6dmvGQrJGTjYpcpHEvqbTXMZenGAsc7vMjKlnkvNMjRpL3HgxfrO+3r TYr/4SP8HhxI+Z54hIbo0XF2oDkd5on9QLe8n7rGrfbJlXlxJ4F3cS1SfDAeWEwjlA6L VKSNmLQn7aBKpS3Y28MPXWq4aMReeJVgNH/SX9lzPlIrQoUp7b3+p8/8iG0BqNeYPno4 z92GiMr+e59rizpxbaj6K8MM0OMF53wI/CUf1Bw6Pe8h+5NqSFXsy+ETwh3kmoMnAwB2 UVpA== 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=ToWY0R45y8BHjmAdWxteY+oDuIkdik3lI8PSNGM4h2M=; b=twBeoNjoL/7iMiDz72CzwNzvFcmLNF3C3X1pApCmNC8p8W9ce8yQuq13sFXBOJ8mi7 pgiNzv8C0Cf9vGtai3GXzVRs0beiphXdfTuOqgrWJ2LhT+HAbKt4EYElRD+5QNsQ2/Q5 nFvbPJ3gA/hFkKBv7TogrTUQhRnFYaqFS6FX9+jM37xXTD6e4+PE/g5/oAS3LZ2LC74d C5Wr1EBhUakIzfZEcQhT2hNVvf3dE+Of9NPfxdGRxKBRwxEgB6XOU66OK3pEu/aL7RyY ZjBoDkAdV2p2a5SWcrguL8Y2juE3IMa7y92cSnL0Fu5aeTL1EQtjRsgc0ISMEA22o9Gr aArA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@messagingengine.com header.s=fm2 header.b=uOGReI6S; 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 a75si6096017qkb.166.2019.04.10.18.35.47 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 10 Apr 2019 18:35:47 -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=uOGReI6S; 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 4D04F13FF0; Wed, 10 Apr 2019 21:35:47 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute3.internal (MEProxy); Wed, 10 Apr 2019 21:35:47 -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=ToWY0R45y8BHjmAdWxteY+oDuIkdik3lI8PSNGM4h2M=; b=uOGReI6S ys0onALU/h3kW47M6AwIWq2JgRc/lEMak4Ca7PEEtBALSeO4HXaUwLNC04E6/Fvh YfhVbeexbKw1VlQJ3zmIluQ7xE0ait8P6aFHrzZJjXgJfgnh7DaqtfjRAdXHrJ4u CcODF30Pcpoq6+QwpR8nRq/Y9ShYjCH6JcM2UEqZnovNYjjg/LuQzrBIZivniIez uFcdPXW8ygxBrtMjZjcYMNZFlqTxsm4+4Zc/WbkeyZPTUhbRfQLw6WcRxivyumna HHYfM7/aMMYv4GXgidZsg3KlRrQ6s0oQWHANlW44htj3vuTurgG1mUEkc4eUxmj9 q964rRqEXeYI4g== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduuddrudekgdegvdcutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenuc fjughrpefhvffufffkofgjfhgggfestdekredtredttdenucfhrhhomhepfdfvohgsihhn ucevrdcujfgrrhguihhnghdfuceothhosghinheskhgvrhhnvghlrdhorhhgqeenucfkph epuddvgedrudejuddrudelrdduleegnecurfgrrhgrmhepmhgrihhlfhhrohhmpehtohgs ihhnsehkvghrnhgvlhdrohhrghenucevlhhushhtvghrufhiiigvpedt X-ME-Proxy: Received: from eros.localdomain (124-171-19-194.dyn.iinet.net.au [124.171.19.194]) by mail.messagingengine.com (Postfix) with ESMTPA id 3A32CE408B; Wed, 10 Apr 2019 21:35:37 -0400 (EDT) From: "Tobin C. Harding" To: Andrew Morton Cc: "Tobin C. Harding" , Roman Gushchin , Alexander Viro , Christoph Hellwig , Pekka Enberg , David Rientjes , Joonsoo Kim , Christopher Lameter , Matthew Wilcox , 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 v3 01/15] slub: Add isolate() and migrate() methods Date: Thu, 11 Apr 2019 11:34:27 +1000 Message-Id: <20190411013441.5415-2-tobin@kernel.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190411013441.5415-1-tobin@kernel.org> References: <20190411013441.5415-1-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 --- 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 d30ede89f4a6..ae44d640b8c1 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -4326,6 +4326,33 @@ 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; @@ -5010,13 +5037,33 @@ 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) { @@ -5429,7 +5476,7 @@ 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,