From nobody Sun Sep 14 09:42:07 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 F2D26C77B73 for ; Wed, 19 Apr 2023 12:50:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233119AbjDSMuz (ORCPT ); Wed, 19 Apr 2023 08:50:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34322 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232992AbjDSMuv (ORCPT ); Wed, 19 Apr 2023 08:50:51 -0400 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 79EB96EAD for ; Wed, 19 Apr 2023 05:50:41 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-54fde069e4aso133812847b3.3 for ; Wed, 19 Apr 2023 05:50:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1681908640; x=1684500640; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=M55eRuHQJrupxqsaP770qxmiyWjSxTprBCDKIWruVU8=; b=LXjy63dN+KA/a+ihM+Hvrk/noXBuUo93Q35thIox5tSdDL2o71/NMZqFSYRW0EBM4P EFX9I9zPzMnxSNaBMaLHxoq+qKvEcsWsmeEXD3h2XX8VP1TN70UUtZrcF025i79nZDqa VYi1WpoKBj5pu+akQ/sWrJLnII87r+R3KLUmrXRQRQY92oMrME3VBmxN7sElDqCBoWrx lXo+oopgXDC+bwQHMXVYMf3RRHvxlbwsNLPAsX5CrT4gmHs2cj/cjZhAZINSVAWMoNCH n+pDViYF29j82CWSRE3IgGrfv302KxrSw7qSMoOyeUOz03lZl110Yp6DcbGXZyKaYWi0 XLZg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1681908640; x=1684500640; 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=M55eRuHQJrupxqsaP770qxmiyWjSxTprBCDKIWruVU8=; b=IrvAPAUWWjfKV2APoqSn9/F+gIDeCIR3qKbb4e07tPYzvZeEdZrq9e1A//r8ue0P8a kpa1oKGQ1N4yWVa/bW98gxZWfnRJo3dRpAhyM9HZSBB8rrc5QeUYiCLEZJEwxMH4gld/ FhAJT1Zz8Qbfp5OH1UjJQGaULcpMlxn7ccWTqVMWZutJf2ZRdyPOGCujWj5w70BAJSFq N1NhIagVcMveGmq7OyoyUaYRektHbUpcuV2pD8/auCuByJlyfNUu3lmDBZ6qexEIBs+T WmZWHxf6ZEKD8DZFMUSEhePcxfK10jx/zeft3h1j4W8PGmK8UC0/WmoDjogizPryeLhr JjdA== X-Gm-Message-State: AAQBX9e8vaVuvay+Lj8zQ/RvRCcGUg1kk37x7GBu0OKBppwnij0SYRbd D1pxbbIT06v8m5dtDosqqfla2D7seuN+D/j3Pg== X-Google-Smtp-Source: AKy350bHCu6N/9gE0Xr0AQjCLyCYOOOEiAnM+qBQM/oKHnm8lOsLRsxUyXnZgd1futy7TWNiA6JxT/4GV9CrMcsl6A== X-Received: from peternewman0.zrh.corp.google.com ([2a00:79e0:9d:6:b36e:a25e:826d:b66a]) (user=peternewman job=sendgmr) by 2002:a25:c245:0:b0:997:c919:4484 with SMTP id s66-20020a25c245000000b00997c9194484mr11392762ybf.6.1681908640818; Wed, 19 Apr 2023 05:50:40 -0700 (PDT) Date: Wed, 19 Apr 2023 14:50:13 +0200 In-Reply-To: <20230419125015.693566-1-peternewman@google.com> Mime-Version: 1.0 References: <20230419125015.693566-1-peternewman@google.com> X-Mailer: git-send-email 2.40.0.634.g4ca3ef3211-goog Message-ID: <20230419125015.693566-2-peternewman@google.com> Subject: [PATCH v6 1/3] 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, skodak@google.com, tglx@linutronix.de, tony.luck@intel.com, 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 reference 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}(). No functional change. Signed-off-by: Peter Newman Reviewed-by: Reinette Chatre --- 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 6ad33f355861..51b869149e76 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -2301,6 +2301,26 @@ 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); @@ -2308,8 +2328,7 @@ 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 @@ -2328,17 +2347,7 @@ 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 2.40.0.634.g4ca3ef3211-goog