From patchwork Mon Nov 13 19:14:01 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vlastimil Babka X-Patchwork-Id: 164621 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:b909:0:b0:403:3b70:6f57 with SMTP id t9csp1421342vqg; Mon, 13 Nov 2023 11:17:11 -0800 (PST) X-Google-Smtp-Source: AGHT+IHsYHm72nY1fuWXfupfIAD10efaiynSot33zp5W8O4rM/ZSisrfBX05Qm/g61fL9tgtQ/If X-Received: by 2002:a17:902:f70c:b0:1cc:5aef:f2c1 with SMTP id h12-20020a170902f70c00b001cc5aeff2c1mr190986plo.33.1699903030982; Mon, 13 Nov 2023 11:17:10 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1699903030; cv=none; d=google.com; s=arc-20160816; b=umM8Gsj1R/ROVCCu6yx7LPkyRfND6j0+lROc2Jj9O51NHiqL9hbiWoptRHA+5wYdVB x7MO5IWJPCVSlbLr9bTGGsnxQQ9eY+ja+4+QhjwnDmMpCiWy4cee3I6AzvqdXTsl9sWs +A8wp3IJy2SBW5KrAuWLW2QmrxeGGupBxDt/iWU/hxUF0j64lM7pqgkSbhTF6oC2dfAD MdG1J092mA72qeWO5hiaphruj0rYs4NRX217GdHe9OS/WmMdKQqKmKz412SgIFin9dpS pcEXbIw9SyipKgiFnKI8VFHRBlriF19myvIbQKP1bSWLGQJFidSVlvGth/hIQzPSE9yG f/qg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature:dkim-signature; bh=HPRL/KrzqhhRv//jIzaBEKs7IEvhqlXTEPf11LGvT+E=; fh=RPAmrUlnQQdc1FhCirEqyhGh/OnPyRxUfAdj7ygPMx4=; b=ZqOocDZsdITn/OGG1nxsCWqKb14kcITSAb2R+UT9+oySiZ17130/fFkMcsIo/abDlO iuuHkP61A3G2Y6DeOvAENSzr1Q8I2lGACa0cu1kGzhUz+I7iIxDZJfBMnlaspHrrR4U4 lJCdr+Hk67sQbN+ycmuBGpxaPHylF5oPOwfpY7cu8kVAZoUDE4IdLLUYLjIomvSdKJBA I0rr9i9WyNYfQJcMo5yT3HYWc6wdyOmwrP6k5X1HY/XUfk9DuyhpXIWtdMjwAE4/Rc6I LDKp3lCw8ADrM+mDdB0GbjEfzSfug9c3GK3m+4qe5Jl6t3W9LCxOLzgX472vPz/dXSBx AYQw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@suse.cz header.s=susede2_rsa header.b=MCduxZYm; dkim=neutral (no key) header.i=@suse.cz header.b=V8jBNiQR; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:2 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: from agentk.vger.email (agentk.vger.email. [2620:137:e000::3:2]) by mx.google.com with ESMTPS id t11-20020a1709028c8b00b001ca38020ca3si6073388plo.629.2023.11.13.11.17.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 13 Nov 2023 11:17:10 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:2 as permitted sender) client-ip=2620:137:e000::3:2; Authentication-Results: mx.google.com; dkim=pass header.i=@suse.cz header.s=susede2_rsa header.b=MCduxZYm; dkim=neutral (no key) header.i=@suse.cz header.b=V8jBNiQR; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:2 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: from out1.vger.email (depot.vger.email [IPv6:2620:137:e000::3:0]) by agentk.vger.email (Postfix) with ESMTP id 55B65807FCC5; Mon, 13 Nov 2023 11:17:02 -0800 (PST) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.11 at agentk.vger.email Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232268AbjKMTPN (ORCPT + 30 others); Mon, 13 Nov 2023 14:15:13 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50186 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231917AbjKMTO1 (ORCPT ); Mon, 13 Nov 2023 14:14:27 -0500 Received: from smtp-out2.suse.de (smtp-out2.suse.de [IPv6:2001:67c:2178:6::1d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 71F661739; Mon, 13 Nov 2023 11:14:17 -0800 (PST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 237611F88F; Mon, 13 Nov 2023 19:14:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1699902856; h=from:from:reply-to: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=HPRL/KrzqhhRv//jIzaBEKs7IEvhqlXTEPf11LGvT+E=; b=MCduxZYmVuQsqxVK7yN6VRgd6oRH1+OX+bZLl8Vq/FjOKSCiK1k9AbIeXyymmv5FFiChqN BrILdcy4pVskHuPR1IM6wOan8Zd7bZZfAX9X8kZte2Wtwcm+KZ7P4HFKM5WjJe/L4pdaPg C72FBd07XRG9KFPVqy66V6Gvg2vePOk= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1699902856; h=from:from:reply-to: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=HPRL/KrzqhhRv//jIzaBEKs7IEvhqlXTEPf11LGvT+E=; b=V8jBNiQRZxe6eGxYJtbNWf/MQPc4nz18AGu/sDaheaWDiPfd7VFSosfgTjsJi1S0XqFTQK D7rYRLY+Nl5VtdBg== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id C7F5313398; Mon, 13 Nov 2023 19:14:15 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id aLpDMId1UmVFOgAAMHmgww (envelope-from ); Mon, 13 Nov 2023 19:14:15 +0000 From: Vlastimil Babka To: David Rientjes , Christoph Lameter , Pekka Enberg , Joonsoo Kim Cc: Andrew Morton , Hyeonggon Yoo <42.hyeyoo@gmail.com>, Roman Gushchin , linux-mm@kvack.org, linux-kernel@vger.kernel.org, patches@lists.linux.dev, Andrey Ryabinin , Alexander Potapenko , Andrey Konovalov , Dmitry Vyukov , Vincenzo Frascino , Marco Elver , Johannes Weiner , Michal Hocko , Shakeel Butt , Muchun Song , Kees Cook , kasan-dev@googlegroups.com, cgroups@vger.kernel.org, Vlastimil Babka Subject: [PATCH 20/20] mm/slub: optimize free fast path code layout Date: Mon, 13 Nov 2023 20:14:01 +0100 Message-ID: <20231113191340.17482-42-vbabka@suse.cz> X-Mailer: git-send-email 2.42.1 In-Reply-To: <20231113191340.17482-22-vbabka@suse.cz> References: <20231113191340.17482-22-vbabka@suse.cz> MIME-Version: 1.0 X-Spam-Status: No, score=-0.9 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on agentk.vger.email Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (agentk.vger.email [0.0.0.0]); Mon, 13 Nov 2023 11:17:02 -0800 (PST) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1782477520723188074 X-GMAIL-MSGID: 1782477520723188074 Inspection of kmem_cache_free() disassembly showed we could make the fast path smaller by providing few more hints to the compiler, and splitting the memcg_slab_free_hook() into an inline part that only checks if there's work to do, and an out of line part doing the actual uncharge. bloat-o-meter results: add/remove: 2/0 grow/shrink: 0/3 up/down: 286/-554 (-268) Function old new delta __memcg_slab_free_hook - 270 +270 __pfx___memcg_slab_free_hook - 16 +16 kfree 828 665 -163 kmem_cache_free 1116 948 -168 kmem_cache_free_bulk.part 1701 1478 -223 Checking kmem_cache_free() disassembly now shows the non-fastpath cases are handled out of line, which should reduce instruction cache usage. Signed-off-by: Vlastimil Babka --- mm/slub.c | 40 ++++++++++++++++++++++++---------------- 1 file changed, 24 insertions(+), 16 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index 7a40132b717a..ae1e6e635253 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1959,20 +1959,11 @@ void memcg_slab_post_alloc_hook(struct kmem_cache *s, struct obj_cgroup *objcg, return __memcg_slab_post_alloc_hook(s, objcg, flags, size, p); } -static inline void memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab, - void **p, int objects) +static void __memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab, + void **p, int objects, + struct obj_cgroup **objcgs) { - struct obj_cgroup **objcgs; - int i; - - if (!memcg_kmem_online()) - return; - - objcgs = slab_objcgs(slab); - if (!objcgs) - return; - - for (i = 0; i < objects; i++) { + for (int i = 0; i < objects; i++) { struct obj_cgroup *objcg; unsigned int off; @@ -1988,6 +1979,22 @@ static inline void memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab, obj_cgroup_put(objcg); } } + +static __fastpath_inline +void memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab, void **p, + int objects) +{ + struct obj_cgroup **objcgs; + + if (!memcg_kmem_online()) + return; + + objcgs = slab_objcgs(slab); + if (likely(!objcgs)) + return; + + __memcg_slab_free_hook(s, slab, p, objects, objcgs); +} #else /* CONFIG_MEMCG_KMEM */ static inline struct mem_cgroup *memcg_from_slab_obj(void *ptr) { @@ -2047,7 +2054,7 @@ static __always_inline bool slab_free_hook(struct kmem_cache *s, * The initialization memset's clear the object and the metadata, * but don't touch the SLAB redzone. */ - if (init) { + if (unlikely(init)) { int rsize; if (!kasan_has_integrated_init()) @@ -2083,7 +2090,8 @@ static inline bool slab_free_freelist_hook(struct kmem_cache *s, next = get_freepointer(s, object); /* If object's reuse doesn't have to be delayed */ - if (!slab_free_hook(s, object, slab_want_init_on_free(s))) { + if (likely(!slab_free_hook(s, object, + slab_want_init_on_free(s)))) { /* Move object to the new freelist */ set_freepointer(s, object, *head); *head = object; @@ -4270,7 +4278,7 @@ static __fastpath_inline void slab_free(struct kmem_cache *s, struct slab *slab, * With KASAN enabled slab_free_freelist_hook modifies the freelist * to remove objects, whose reuse must be delayed. */ - if (slab_free_freelist_hook(s, &head, &tail, &cnt)) + if (likely(slab_free_freelist_hook(s, &head, &tail, &cnt))) do_slab_free(s, slab, head, tail, cnt, addr); }