From nobody Mon Apr 13 18:44:40 2026 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 E440FC433FE for ; Tue, 15 Nov 2022 15:45:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238284AbiKOPpy (ORCPT ); Tue, 15 Nov 2022 10:45:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43288 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231347AbiKOPps (ORCPT ); Tue, 15 Nov 2022 10:45:48 -0500 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 779FF10565 for ; Tue, 15 Nov 2022 07:45:47 -0800 (PST) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-370624ca2e8so138944817b3.16 for ; Tue, 15 Nov 2022 07:45:47 -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=cUFeRtZYB7UeTgxIn2ZhYMocLTGExrmRKO4xcP78LzE=; b=Si5zz34w8W5OUKEmuwma1mET23o1UNMM0e+o9fGg5w5QBLXN0EQOINeapJXw0xkhN5 jIBGAQpEgsaEeu2F7RJfTUTekBnD5xmh7oO3DT9e/g5GH9xCDINR/nnIH1JQBtjCA8Ky cGd2mkkePepc9zsCKoQBhNWoANyqmXIHeOPNSUqILXJ+JDo0m+Fg58+w9dEi+qyzv9PK mkkEjCyPJL2UD0KfMddbIdEX6IIwT+BCGM1qp7vQZJ89JXMBRgZua0U4jSF0TfY/8A3L P5OCi+bq6OzDA/4TybR/avT7cMQ6ZUIN1MQpCKdkmJhl6PAQflUILq9El2VnyO7VmIPI Ckig== 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=cUFeRtZYB7UeTgxIn2ZhYMocLTGExrmRKO4xcP78LzE=; b=UAoHqmIwUjv6pmHoHfLUzdnwzEEavYeH5PIg7sBNDDyfPF/szhhHAxawbSnelet5v9 z0C+rTMXMmMjyT+TW96ti0hrcMVK7WPJFJGkZqJWXx9oenxvbYNyHvw2uuDnntNLVeJr r4hN+leZO8qlwdt0o+9sr6ouXLGjrUhTAC6umz2gpNxv1hIXIdYj/G6wvKdNUvvbUKHK 7sBOQuExuKbLpKo7OAjBcxD910I9MbGVJ7oTkOoQfTHCzbevutu17iH+xWVSAiWUDy3C VafdGZfURm6GY7nByFRNSSM9fgGzQqgnsukO1BlRo8HPwk7WzopofWAry5rP+/Dam4+q 37FA== X-Gm-Message-State: ANoB5pmqsQSnvWCN+RWeDRP6OajdBGKggHz8xkbxLT2QpE5PV+NWQmG5 qP4LYytun7sphLNWJfh6IIc18IJgS/0egFZvPg== X-Google-Smtp-Source: AA0mqf69A0hZw4IJg/9Hpym+IBCNApy2UjMUCdqSJlD8FX/eyVqv53ZuVqcM51FoPNf2fzyMh+wKHprvlaeRH4bg9Q== X-Received: from peternewman10.zrh.corp.google.com ([2a00:79e0:9d:6:fe62:9ede:ae13:6fda]) (user=peternewman job=sendgmr) by 2002:a25:40ce:0:b0:6d5:34ad:10c5 with SMTP id n197-20020a2540ce000000b006d534ad10c5mr28033116yba.494.1668527146292; Tue, 15 Nov 2022 07:45:46 -0800 (PST) Date: Tue, 15 Nov 2022 16:45:14 +0100 In-Reply-To: <20221115154515.952783-1-peternewman@google.com> Mime-Version: 1.0 References: <20221115154515.952783-1-peternewman@google.com> X-Mailer: git-send-email 2.38.1.493.g58b659f92b-goog Message-ID: <20221115154515.952783-2-peternewman@google.com> Subject: [PATCH v1 1/2] x86/resctrl: factor rdtgroup lock for multi-file ops From: Peter Newman To: Fenghua Yu , Reinette Chatre Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , James Morse , Stephane Eranian , Gaurang Upasani , Babu Moger , linux-kernel@vger.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" To help implement kernfs 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}(). The existing rdtgroup_kn_lock_live() could only release the kernfs lock for a single file before waiting on the rdtgroup_mutex. 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 2.38.1.493.g58b659f92b-goog