From patchwork Wed Jun 14 11:03:24 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yajun Deng X-Patchwork-Id: 107894 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:994d:0:b0:3d9:f83d:47d9 with SMTP id k13csp1159556vqr; Wed, 14 Jun 2023 04:11:05 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ5B8xtTbsj95K96W0mr4TQWJDqU6+vk71FofiuBIhpMG58TvD0p3H0Auz07+QDqSrVw8SAl X-Received: by 2002:a05:6808:1909:b0:397:f1b3:f940 with SMTP id bf9-20020a056808190900b00397f1b3f940mr11396396oib.27.1686741065311; Wed, 14 Jun 2023 04:11:05 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1686741065; cv=none; d=google.com; s=arc-20160816; b=Ux/NdO5Uk9lGSUXZOT/uxs7MM8UOb0GVZxudscqEirkjqK0NlB334PSRhGQZFun+ye lwHfQqxf5wJjby2lRTYVd037BCoEC2rX5oPoA+m6/zJHTTeN58F8gQjRwSF1fIH71rB3 5zLjE7a9caN0djK2f4glkn3/b7cri7j+Wg+0sRFGKXOx92lKu+22HhMJarkbBOKCHGqA FuSJjCSdaSg9QsWCK6xGmHk75q64d7VqQiCIa/pFUbXEe400yH5oIZohuFHC8F5/K2Z2 mlDMn3ruuNgO5Mjuh7Ch8ernUiOkZT112RRFzbgQsn8q7nmbC06Y+iT7IqjPvvtPgbsh 7LFg== 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 :message-id:date:subject:cc:to:from:dkim-signature; bh=JUAXO3nF4TYUh7G4bGQ31E/7+rub4uhiLNTBrM2ujC8=; b=eogMu5VWOWPy88rGiNuL7+G0GBiRlUv7eclGAUN9x50CQzDWsSCivAhpdbBcUZi0la ta0Equt1teNN5cp/+3DGawUUv6bmBlzycKG3xXOAYm1pqVduk/lnxlHJf8+7NqtXdtNH faLH9GziyISR7MTRdU0wXbvOlku1+usR33POrI0E7b4pE8MoQeRDW8aIrvOpT1rcdTAS QSqZkCDtzqp7VSCN7hZpbrp3GeV7nD7ZlbHQoZSwtcuoLZsnzFL0E7oODOOcJVTXWJeH kB0s6/jflxIpOMQT2kcdSK7N2Qfrn9ve2uFvShoKa+hE9Ie6p8OhbHU0CEh3Vrp20YJ8 2/fA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linux.dev header.s=key1 header.b=P06EKQSY; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linux.dev Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id c5-20020a621c05000000b0065d565b6b33si10616005pfc.33.2023.06.14.04.10.49; Wed, 14 Jun 2023 04:11:05 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@linux.dev header.s=key1 header.b=P06EKQSY; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linux.dev Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243511AbjFNLD7 (ORCPT + 99 others); Wed, 14 Jun 2023 07:03:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33008 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236214AbjFNLDo (ORCPT ); Wed, 14 Jun 2023 07:03:44 -0400 Received: from out-62.mta1.migadu.com (out-62.mta1.migadu.com [95.215.58.62]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8069A1BE5 for ; Wed, 14 Jun 2023 04:03:42 -0700 (PDT) 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=1686740617; 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; bh=JUAXO3nF4TYUh7G4bGQ31E/7+rub4uhiLNTBrM2ujC8=; b=P06EKQSYiSzPJZCUwYNF5LhDGDRkWumiodO74KPIgoDsJrSSb2UrF6A7dqnDxkcI4mWLjI nb9+BJDG2syeWPi7IUgLgHswlfW/eBUTP6IOeABhyIBQQry9VGuTvpKhY+7YUZVYrZN8jH k9zNpZiJ+8Ve3g+BfGPpBFZezTn8LhM= From: Yajun Deng To: gregkh@linuxfoundation.org, rafael@kernel.org, rppt@kernel.org, akpm@linux-foundation.org Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Yajun Deng Subject: [PATCH] mm/mm_init.c: remove spinlock in early_pfn_to_nid() Date: Wed, 14 Jun 2023 19:03:24 +0800 Message-Id: <20230614110324.3839354-1-yajun.deng@linux.dev> MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,SPF_HELO_NONE,SPF_PASS, T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1768676199273240410?= X-GMAIL-MSGID: =?utf-8?q?1768676199273240410?= When the system boots, only one cpu is enabled before smp_init(). So the spinlock is not needed in most cases, remove it. Add spinlock in get_nid_for_pfn() because it is after smp_init(). Signed-off-by: Yajun Deng --- drivers/base/node.c | 11 +++++++++-- mm/mm_init.c | 18 +++--------------- 2 files changed, 12 insertions(+), 17 deletions(-) diff --git a/drivers/base/node.c b/drivers/base/node.c index 9de524e56307..844102570ff2 100644 --- a/drivers/base/node.c +++ b/drivers/base/node.c @@ -748,8 +748,15 @@ int unregister_cpu_under_node(unsigned int cpu, unsigned int nid) static int __ref get_nid_for_pfn(unsigned long pfn) { #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT - if (system_state < SYSTEM_RUNNING) - return early_pfn_to_nid(pfn); + static DEFINE_SPINLOCK(early_pfn_lock); + int nid; + + if (system_state < SYSTEM_RUNNING) { + spin_lock(&early_pfn_lock); + nid = early_pfn_to_nid(pfn); + spin_unlock(&early_pfn_lock); + return nid; + } #endif return pfn_to_nid(pfn); } diff --git a/mm/mm_init.c b/mm/mm_init.c index d393631599a7..5895a30435ee 100644 --- a/mm/mm_init.c +++ b/mm/mm_init.c @@ -584,11 +584,11 @@ struct mminit_pfnnid_cache { static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata; /* - * Required by SPARSEMEM. Given a PFN, return what node the PFN is on. + * Given a PFN, return what node the PFN is on. */ -static int __meminit __early_pfn_to_nid(unsigned long pfn, - struct mminit_pfnnid_cache *state) +int __meminit early_pfn_to_nid(unsigned long pfn) { + struct mminit_pfnnid_cache *state = &early_pfnnid_cache; unsigned long start_pfn, end_pfn; int nid; @@ -601,20 +601,8 @@ static int __meminit __early_pfn_to_nid(unsigned long pfn, state->last_end = end_pfn; state->last_nid = nid; } - - return nid; -} - -int __meminit early_pfn_to_nid(unsigned long pfn) -{ - static DEFINE_SPINLOCK(early_pfn_lock); - int nid; - - spin_lock(&early_pfn_lock); - nid = __early_pfn_to_nid(pfn, &early_pfnnid_cache); if (nid < 0) nid = first_online_node; - spin_unlock(&early_pfn_lock); return nid; }