From patchwork Tue Apr 28 20:58:47 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Uladzislau Rezki X-Patchwork-Id: 11515569 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3B0991805 for ; Tue, 28 Apr 2020 20:59:48 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 093FB20737 for ; Tue, 28 Apr 2020 20:59:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Jp/cGmJk" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 093FB20737 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id E95848E000D; Tue, 28 Apr 2020 16:59:40 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id E06FF8E0007; Tue, 28 Apr 2020 16:59:40 -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 CE2BC8E000D; Tue, 28 Apr 2020 16:59:40 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0124.hostedemail.com [216.40.44.124]) by kanga.kvack.org (Postfix) with ESMTP id B3CA78E0007 for ; Tue, 28 Apr 2020 16:59:40 -0400 (EDT) Received: from smtpin04.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 708D85828 for ; Tue, 28 Apr 2020 20:59:40 +0000 (UTC) X-FDA: 76758480120.04.soup86_54689d2252551 X-Spam-Summary: 2,0,0,ca64c452bfa882fe,d41d8cd98f00b204,urezki@gmail.com,,RULES_HIT:41:355:379:541:800:960:966:968:973:988:989:1260:1311:1314:1345:1359:1437:1515:1535:1542:1711:1730:1747:1777:1792:2194:2196:2199:2200:2393:2559:2562:2901:3138:3139:3140:3141:3142:3354:3865:3866:3867:3868:3870:3871:3872:3874:4117:4385:5007:6117:6261:6653:7514:7576:9413:10004:11026:11473:11658:11914:12043:12296:12297:12438:12517:12519:12555:12679:12895:13161:13229:13868:13894:14181:14394:14687:14721:21080:21444:21451:21627:21666:21740:21990:30012:30054:30070,0,RBL:209.85.208.195:@gmail.com:.lbl8.mailshell.net-62.18.0.100 66.100.201.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:23,LUA_SUMMARY:none X-HE-Tag: soup86_54689d2252551 X-Filterd-Recvd-Size: 6161 Received: from mail-lj1-f195.google.com (mail-lj1-f195.google.com [209.85.208.195]) by imf48.hostedemail.com (Postfix) with ESMTP for ; Tue, 28 Apr 2020 20:59:39 +0000 (UTC) Received: by mail-lj1-f195.google.com with SMTP id l19so197664lje.10 for ; Tue, 28 Apr 2020 13:59:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=KpPRWZDvG8CgK8dZKCEsG9Emj5dGIpU0eqSTK3oTu4U=; b=Jp/cGmJks3FbPmO6cnSdkivz7OJHf87NIdc550TYVUo5oyct/fknb8SeQgG/Wa6AvT j1s4N78U0TRqqfWCoy4Cnwkj6gYaJjhBPoPA4SDXFmJLkSgX/GEs/heihzFRtuULBLuR ydXaywn1Lar7YFPryFl7cTeTeik4WiCd59r+Y9nk9wFiAtp1oezC4vFzgKC81AgGdBDL STIicmNXYpDyWAknzGXu+U4RdBzyt0gcZaLuVfHNt3i11xsecqtZeCVI8ivDe15kcRl0 qrTiYkXv2wP3a7zEMIu2PMB0JHWoYrUnSoEO4DbpVVTeg46tQ5FPN0LKzJqMmpMJ/Mzu a/yQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=KpPRWZDvG8CgK8dZKCEsG9Emj5dGIpU0eqSTK3oTu4U=; b=OnWcX6vz4YP5CYDrFrrFa6+9tg5xbYn4q7M9IbmMRS1TzDF+E3hHvjmLzzd5dOXLNb bA3BIFCKWwXZc/LqfdGUuRE1kcqPfdlJ0hzz0SKhqXYOe/afnYE25MJvn9VOhYHp7E3q om42pdf59/xTeZXENPrOHTi6pIeIQK7rXFo+e3SNAommXaZR6Edx+ssdT6U+8MHjq41q NU1+QmRSxanAXPg/UzCmCiYfuW7Bt5+L9MyiyzH1Z0J46eSrQMCL1NfFFvfyGMo/L1lZ 1XxNHVPoCh27ugzUq0CoKLIiv6CQTA22t/z3mlKxpI3PKGeusbQnNKswiSXDhtlDouqG AkOw== X-Gm-Message-State: AGi0PuYL1pBKY0Zmc5P511f1MtBJHZhywZQYb3YQaLHu/r1ZiDNJ6XY4 YGDPg2EDcpUxxxdrIhOsIZ4= X-Google-Smtp-Source: APiQypIK0yNKxQMrJ+FmeTtM1yEhM2Bk+cTVBWd0YgRswTk8U0gkkBZkwM/NPoG1ukrhwMQjsmSyPQ== X-Received: by 2002:a2e:9713:: with SMTP id r19mr19379545lji.89.1588107578198; Tue, 28 Apr 2020 13:59:38 -0700 (PDT) Received: from pc638.lan (h5ef52e31.seluork.dyn.perspektivbredband.net. [94.245.46.49]) by smtp.gmail.com with ESMTPSA id z21sm295483ljh.42.2020.04.28.13.59.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 28 Apr 2020 13:59:37 -0700 (PDT) From: "Uladzislau Rezki (Sony)" To: LKML , linux-mm@kvack.org Cc: Andrew Morton , "Paul E . McKenney" , "Theodore Y . Ts'o" , Matthew Wilcox , Joel Fernandes , RCU , Uladzislau Rezki , Oleksiy Avramchenko , Sebastian Andrzej Siewior Subject: [PATCH 08/24] rcu/tree: Use static initializer for krc.lock Date: Tue, 28 Apr 2020 22:58:47 +0200 Message-Id: <20200428205903.61704-9-urezki@gmail.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200428205903.61704-1-urezki@gmail.com> References: <20200428205903.61704-1-urezki@gmail.com> 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: From: Sebastian Andrzej Siewior The per-CPU variable is initialized at runtime in kfree_rcu_batch_init(). This function is invoked before 'rcu_scheduler_active' is set to 'RCU_SCHEDULER_RUNNING'. After the initialisation, '->initialized' is to true. The raw_spin_lock is only acquired if '->initialized' is set to true. The worqueue item is only used if 'rcu_scheduler_active' set to RCU_SCHEDULER_RUNNING which happens after initialisation. Use a static initializer for krc.lock and remove the runtime initialisation of the lock. Since the lock can now be always acquired, remove the '->initialized' check. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Uladzislau Rezki (Sony) --- kernel/rcu/tree.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index bc6c2bc8fa32..89e9ca3f4e3e 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2892,7 +2892,7 @@ struct kfree_rcu_cpu_work { * @lock: Synchronize access to this structure * @monitor_work: Promote @head to @head_free after KFREE_DRAIN_JIFFIES * @monitor_todo: Tracks whether a @monitor_work delayed work is pending - * @initialized: The @lock and @rcu_work fields have been initialized + * @initialized: The @rcu_work fields have been initialized * * This is a per-CPU structure. The reason that it is not included in * the rcu_data structure is to permit this code to be extracted from @@ -2912,7 +2912,9 @@ struct kfree_rcu_cpu { int count; }; -static DEFINE_PER_CPU(struct kfree_rcu_cpu, krc); +static DEFINE_PER_CPU(struct kfree_rcu_cpu, krc) = { + .lock = __RAW_SPIN_LOCK_UNLOCKED(krc.lock), +}; static __always_inline void debug_rcu_bhead_unqueue(struct kfree_rcu_bulk_data *bhead) @@ -2930,10 +2932,9 @@ krc_this_cpu_lock(unsigned long *flags) { struct kfree_rcu_cpu *krcp; - local_irq_save(*flags); // For safely calling this_cpu_ptr(). + local_irq_save(*flags); /* For safely calling this_cpu_ptr(). */ krcp = this_cpu_ptr(&krc); - if (likely(krcp->initialized)) - raw_spin_lock(&krcp->lock); + raw_spin_lock(&krcp->lock); return krcp; } @@ -2941,8 +2942,7 @@ krc_this_cpu_lock(unsigned long *flags) static inline void krc_this_cpu_unlock(struct kfree_rcu_cpu *krcp, unsigned long flags) { - if (likely(krcp->initialized)) - raw_spin_unlock(&krcp->lock); + raw_spin_unlock(&krcp->lock); local_irq_restore(flags); } @@ -4168,7 +4168,6 @@ static void __init kfree_rcu_batch_init(void) for_each_possible_cpu(cpu) { struct kfree_rcu_cpu *krcp = per_cpu_ptr(&krc, cpu); - raw_spin_lock_init(&krcp->lock); for (i = 0; i < KFREE_N_BATCHES; i++) { INIT_RCU_WORK(&krcp->krw_arr[i].rcu_work, kfree_rcu_work); krcp->krw_arr[i].krcp = krcp;