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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 28D99C001E0 for ; Sat, 21 Oct 2023 14:44:37 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B71688E0007; Sat, 21 Oct 2023 10:44:36 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id AFB078D0008; Sat, 21 Oct 2023 10:44:36 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9C2B38E0007; Sat, 21 Oct 2023 10:44:36 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 891FF8D0008 for ; Sat, 21 Oct 2023 10:44:36 -0400 (EDT) Received: from smtpin26.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 6993040472 for ; Sat, 21 Oct 2023 14:44:36 +0000 (UTC) X-FDA: 81369739752.26.FFB06AD Received: from out-209.mta1.migadu.com (out-209.mta1.migadu.com [95.215.58.209]) by imf07.hostedemail.com (Postfix) with ESMTP id B3A724000D for ; Sat, 21 Oct 2023 14:44:34 +0000 (UTC) Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=nBlo2iOc; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf07.hostedemail.com: domain of chengming.zhou@linux.dev designates 95.215.58.209 as permitted sender) smtp.mailfrom=chengming.zhou@linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1697899474; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=R6H+QGgDZUUSLw4c5cGh7W9M5d6koieepx0jv1lm/PY=; b=CoF8guRpBPP/r8+dU57KXMRbzXk2cVXwsHlvQZLEqieFl9+mleCiTxL8C607ijPhwf+0AM W/fgYgKt7bqduAVOP5ubbK4u11Lkj25qVue4SHglG47enMGTHVgC5XCDwLEqzpgecvSmGY l88Udtq+2erw7I5nRgUr1csPdUFkht8= ARC-Authentication-Results: i=1; imf07.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=nBlo2iOc; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf07.hostedemail.com: domain of chengming.zhou@linux.dev designates 95.215.58.209 as permitted sender) smtp.mailfrom=chengming.zhou@linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1697899474; a=rsa-sha256; cv=none; b=Wz0Jo7CdOIXo0cwtad8ylTgjpwBFEEBRmTGEnQgQE/FMGvOalr9x/ymQnO9LmKyuxgwMzW XqO10zbKcK0+cbQVqlUd1HfUeCzmqJfMh5+T+avAsB/Vy8xOiVKo/FORgd6K3nCf7N4XXH u3HuhZZhB+UYQsPyVdf7AHt4UiefcYc= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1697899473; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=R6H+QGgDZUUSLw4c5cGh7W9M5d6koieepx0jv1lm/PY=; b=nBlo2iOcMyh6STRK6arKHuu2OtwYxeBOEZUYaYEoR/aFOVymXtmXiP9LRc647ZUIG7Opee H74yoyYmsNA9MpuqduzBOiT57hUIKMOEgLDg2dwwGPS9Y+i0M3NpXEK/xqZUJNEg8VERd+ ScKNE5ibttZh3eJk/XwCQSEMgTaBodM= From: chengming.zhou@linux.dev To: cl@linux.com, penberg@kernel.org Cc: rientjes@google.com, iamjoonsoo.kim@lge.com, akpm@linux-foundation.org, vbabka@suse.cz, roman.gushchin@linux.dev, 42.hyeyoo@gmail.com, willy@infradead.org, pcc@google.com, tytso@mit.edu, maz@kernel.org, ruansy.fnst@fujitsu.com, vishal.moola@gmail.com, lrh2000@pku.edu.cn, hughd@google.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, chengming.zhou@linux.dev, Chengming Zhou Subject: [RFC PATCH v2 6/6] slub: Optimize deactivate_slab() Date: Sat, 21 Oct 2023 14:43:17 +0000 Message-Id: <20231021144317.3400916-7-chengming.zhou@linux.dev> In-Reply-To: <20231021144317.3400916-1-chengming.zhou@linux.dev> References: <20231021144317.3400916-1-chengming.zhou@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Rspam-User: X-Stat-Signature: or1ixf5kga8xyqszbms6897h1oqnwg1c X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: B3A724000D X-HE-Tag: 1697899474-72087 X-HE-Meta: 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 ZBjHvOIQ YolCqwfrNqDuB0BaO0cCghsdpyuh8UObBvoZTnwH+gr51SExMK79+WUtOIjBN0aIVrp089KSd8xWXa5V3YHKxpwJhPHNoM/0LWJigt2rIrjuL+5aJB66TwA0DRh4bKlDSo91AlWMQrJSdvAvK1+tEb9ujbbvlplm7OmIali6fIcadsOmtf1dDseAztxXt/yeupAhYxkapUkVui9wlpBe9NeT9uUlOY3J3BX8SgmgSvNevrCY= 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: From: Chengming Zhou Since the introduce of unfrozen slabs on cpu partial list, we don't need to synchronize the slab frozen state under the node list_lock. The caller of deactivate_slab() and the caller of __slab_free() won't manipulate the slab list concurrently. So we can get node list_lock in the stage three if we need to manipulate the slab list in this path. Signed-off-by: Chengming Zhou --- mm/slub.c | 70 ++++++++++++++++++++----------------------------------- 1 file changed, 25 insertions(+), 45 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index 7fae959c56eb..29a60bfbf9c5 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -2493,10 +2493,8 @@ static void init_kmem_cache_cpus(struct kmem_cache *s) static void deactivate_slab(struct kmem_cache *s, struct slab *slab, void *freelist) { - enum slab_modes { M_NONE, M_PARTIAL, M_FREE, M_FULL_NOLIST }; struct kmem_cache_node *n = get_node(s, slab_nid(slab)); int free_delta = 0; - enum slab_modes mode = M_NONE; void *nextfree, *freelist_iter, *freelist_tail; int tail = DEACTIVATE_TO_HEAD; unsigned long flags = 0; @@ -2543,58 +2541,40 @@ static void deactivate_slab(struct kmem_cache *s, struct slab *slab, * unfrozen and number of objects in the slab may have changed. * Then release lock and retry cmpxchg again. */ -redo: - - old.freelist = READ_ONCE(slab->freelist); - old.counters = READ_ONCE(slab->counters); - VM_BUG_ON(!old.frozen); - - /* Determine target state of the slab */ - new.counters = old.counters; - if (freelist_tail) { - new.inuse -= free_delta; - set_freepointer(s, freelist_tail, old.freelist); - new.freelist = freelist; - } else - new.freelist = old.freelist; + do { + old.freelist = READ_ONCE(slab->freelist); + old.counters = READ_ONCE(slab->counters); + VM_BUG_ON(!old.frozen); + + /* Determine target state of the slab */ + new.counters = old.counters; + new.frozen = 0; + if (freelist_tail) { + new.inuse -= free_delta; + set_freepointer(s, freelist_tail, old.freelist); + new.freelist = freelist; + } else + new.freelist = old.freelist; - new.frozen = 0; + } while (!slab_update_freelist(s, slab, + old.freelist, old.counters, + new.freelist, new.counters, + "unfreezing slab")); + /* + * Stage three: Manipulate the slab list based on the updated state. + */ if (!new.inuse && n->nr_partial >= s->min_partial) { - mode = M_FREE; + stat(s, DEACTIVATE_EMPTY); + discard_slab(s, slab); + stat(s, FREE_SLAB); } else if (new.freelist) { - mode = M_PARTIAL; - /* - * Taking the spinlock removes the possibility that - * acquire_slab() will see a slab that is frozen - */ spin_lock_irqsave(&n->list_lock, flags); - } else { - mode = M_FULL_NOLIST; - } - - - if (!slab_update_freelist(s, slab, - old.freelist, old.counters, - new.freelist, new.counters, - "unfreezing slab")) { - if (mode == M_PARTIAL) - spin_unlock_irqrestore(&n->list_lock, flags); - goto redo; - } - - - if (mode == M_PARTIAL) { add_partial(n, slab, tail); spin_unlock_irqrestore(&n->list_lock, flags); stat(s, tail); - } else if (mode == M_FREE) { - stat(s, DEACTIVATE_EMPTY); - discard_slab(s, slab); - stat(s, FREE_SLAB); - } else if (mode == M_FULL_NOLIST) { + } else stat(s, DEACTIVATE_FULL); - } } #ifdef CONFIG_SLUB_CPU_PARTIAL -- 2.20.1