From nobody Fri Sep 19 05:44:23 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D5542C4321E for ; Tue, 29 Nov 2022 12:03:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233817AbiK2MDL (ORCPT ); Tue, 29 Nov 2022 07:03:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34424 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233446AbiK2MCZ (ORCPT ); Tue, 29 Nov 2022 07:02:25 -0500 Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6C62A1C105 for ; Tue, 29 Nov 2022 04:02:23 -0800 (PST) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-3c9960ad866so46193777b3.4 for ; Tue, 29 Nov 2022 04:02:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=c1IfWFHp5DCIRjiKA/TeeRTh2AwfodazgUFac9Fpba4=; b=qrag6pK4vXNlb/XxqP9rXIRk1oPoO8kFnVqhuDBEdVcmYt1HLwpv7218GphnLolIjm tO0ZntJA3VdfxCbJdAsDc2m/9byccsuxHJgKbmjzVs7GuDi58E8RhVVYpQJUtCfSTEY9 J98PQ9ZKt8hp5Ohvw9uQSe6iIsRTJzatIgZ9qIGjRCpFVa8Upd3vBwO4G39YWBkRMCqx d9wQ5DheEjXcuVlUbodI7d1bLpJG4Y/ESclxNLL1EXWd1tKNAMAv+OM3BorqoEcJKLdT XZhDx+SesoCF5XxvLNQYh7VhdDbsWbYBJ32OAWgVu1Vw4XQIPu3eNn42QOcMqmqueXfq NIPw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=c1IfWFHp5DCIRjiKA/TeeRTh2AwfodazgUFac9Fpba4=; b=cNzV3K/JfIVB5GQnEi7QN9f9FfBpSKLQBmsK4rW3Dn20HwHxRCNNVxLawtd46eF932 cRW9Z/245V9pLKRixoqRHvDh2mRiQbrZAmYbGK/9XmLX25uGaecNqgmrmmokEuLEDC5T TNmL2DL0uL7sePigHkmozGF+qSoInVwaTT8vwZGfNSU2euJcFPObTgHg2B0EIFi9N3dZ ynlSuyAGpiaboa1YKtmJHXh5JjQn7CA5a+aTA3ikSx9I52XjW1ZNVR4C1FAPLYqeFwgz Ja3Gm3eKtu0fZRlWuir1CncMu6ISDxXFP3pri3sqhFHPMZ9fOFwMvbUeWhll+SAtS4Mk VCBQ== X-Gm-Message-State: ANoB5pnXaq8wNdK4FQJUNjNAl/YlZX7hWYO490l2PA4NPD2YiLnGAGcw 35L91QJQQZXHTty8TOXxnGyU23ub1jegZFSZfw== X-Google-Smtp-Source: AA0mqf699TdYNuj2F80QHmXg0wt+6Cg1c10qyoBDJvmAceddZRvC+VI//i0ExoSIMAPEOooHMYDqKlVG7CaMK9kCRQ== X-Received: from peternewman10.zrh.corp.google.com ([2a00:79e0:9d:6:e398:2261:c909:b359]) (user=peternewman job=sendgmr) by 2002:a81:cb06:0:b0:394:5309:68f8 with SMTP id q6-20020a81cb06000000b00394530968f8mr7ywi.317.1669723342256; Tue, 29 Nov 2022 04:02:22 -0800 (PST) Date: Tue, 29 Nov 2022 13:01:48 +0100 In-Reply-To: <20221129120149.1035444-1-peternewman@google.com> Mime-Version: 1.0 References: <20221129120149.1035444-1-peternewman@google.com> X-Mailer: git-send-email 2.38.1.584.g0f3c55d4c2-goog Message-ID: <20221129120149.1035444-2-peternewman@google.com> Subject: [PATCH v2 1/2] x86/resctrl: Factor rdtgroup lock for multi-file ops From: Peter Newman To: fenghua.yu@intel.com, reinette.chatre@intel.com Cc: Babu.Moger@amd.com, bp@alien8.de, dave.hansen@linux.intel.com, eranian@google.com, gupasani@google.com, hpa@zytor.com, james.morse@arm.com, linux-kernel@vger.kernel.org, mingo@redhat.com, tglx@linutronix.de, x86@kernel.org, Peter Newman Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" rdtgroup_kn_lock_live() can only release a kernfs lock for a single file before waiting on the rdtgroup_mutex, limiting its usefulness for operations on multiple files, such as rename. Factor the work needed to respectively break and unbreak active protection on an individual file into rdtgroup_kn_{get,put}(). This refactoring should not result in any functional change. Signed-off-by: Peter Newman --- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 35 ++++++++++++++++---------- 1 file changed, 22 insertions(+), 13 deletions(-) diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/r= esctrl/rdtgroup.c index e5a48f05e787..03b51543c26d 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -2026,6 +2026,26 @@ static struct rdtgroup *kernfs_to_rdtgroup(struct ke= rnfs_node *kn) } } =20 +static void rdtgroup_kn_get(struct rdtgroup *rdtgrp, struct kernfs_node *k= n) +{ + atomic_inc(&rdtgrp->waitcount); + kernfs_break_active_protection(kn); +} + +static void rdtgroup_kn_put(struct rdtgroup *rdtgrp, struct kernfs_node *k= n) +{ + if (atomic_dec_and_test(&rdtgrp->waitcount) && + (rdtgrp->flags & RDT_DELETED)) { + if (rdtgrp->mode =3D=3D RDT_MODE_PSEUDO_LOCKSETUP || + rdtgrp->mode =3D=3D RDT_MODE_PSEUDO_LOCKED) + rdtgroup_pseudo_lock_remove(rdtgrp); + kernfs_unbreak_active_protection(kn); + rdtgroup_remove(rdtgrp); + } else { + kernfs_unbreak_active_protection(kn); + } +} + struct rdtgroup *rdtgroup_kn_lock_live(struct kernfs_node *kn) { struct rdtgroup *rdtgrp =3D kernfs_to_rdtgroup(kn); @@ -2033,8 +2053,7 @@ struct rdtgroup *rdtgroup_kn_lock_live(struct kernfs_= node *kn) if (!rdtgrp) return NULL; =20 - atomic_inc(&rdtgrp->waitcount); - kernfs_break_active_protection(kn); + rdtgroup_kn_get(rdtgrp, kn); =20 mutex_lock(&rdtgroup_mutex); =20 @@ -2053,17 +2072,7 @@ void rdtgroup_kn_unlock(struct kernfs_node *kn) return; =20 mutex_unlock(&rdtgroup_mutex); - - if (atomic_dec_and_test(&rdtgrp->waitcount) && - (rdtgrp->flags & RDT_DELETED)) { - if (rdtgrp->mode =3D=3D RDT_MODE_PSEUDO_LOCKSETUP || - rdtgrp->mode =3D=3D RDT_MODE_PSEUDO_LOCKED) - rdtgroup_pseudo_lock_remove(rdtgrp); - kernfs_unbreak_active_protection(kn); - rdtgroup_remove(rdtgrp); - } else { - kernfs_unbreak_active_protection(kn); - } + rdtgroup_kn_put(rdtgrp, kn); } =20 static int mkdir_mondata_all(struct kernfs_node *parent_kn, --=20 2.38.1.584.g0f3c55d4c2-goog