From nobody Sat Apr 11 18:53:48 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 79D8FC6FD1D for ; Thu, 30 Mar 2023 13:56:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232225AbjC3N4V (ORCPT ); Thu, 30 Mar 2023 09:56:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43570 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232090AbjC3N4Q (ORCPT ); Thu, 30 Mar 2023 09:56:16 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E3EA67ED3 for ; Thu, 30 Mar 2023 06:56:14 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id p12-20020a25420c000000b00b6eb3c67574so18710889yba.11 for ; Thu, 30 Mar 2023 06:56:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; t=1680184574; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=Db8tOgMamx6SeqgPHUVcNRbWY9TzQjouDMjbLfKO9Bs=; b=smbJl9qFP0l+li/hTveSDyoWOwzoPsoLgc8Y/ZUlzb4z79RlsRniVMcWs8fQnlPjSe aZIByw2LkyVG+iujSfkEbBIxijps0U3JAGOLzKQD9VF1QS6DCfGVK5PsbLIIh3MtvbGo T3VY05+yvWDx1cCieWInbheUEtsfNdp1dtZDEiXe5SSdR+eR8joFUtII4AWaimvlXvG/ sfl8ELaGwsoupYMFHqtKEz38EFqsNC1R1YPxJO4rYlNrGruq5MFrZBGFSN37GhwGY3YM EiffeAwYzCqWYR2AfbaJ5EMGJt94EYC2UWzEKmgiyjaM0LGsMIo42eXzY/vwAOpfHseR 5XvA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680184574; 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=Db8tOgMamx6SeqgPHUVcNRbWY9TzQjouDMjbLfKO9Bs=; b=gU9E7ULLyDdmcirBkjTeTWqU4+iGJdrcdwnCLHw7oP7fkqL5krbwnGGb/oOrnYis3f Jx+p2aNKbLcrYy/La0AzK0NIOheOmkO346hXUuI2Y4z881rqzphx07V3Fh0AyBxhjrAE 57WpW+bRcoF7FfJByqZfijavVtvNdlwIjLysTBS68fZUD+nVuvUKF4I2A93ERrJRcmVj 7fOi7n+AJEPS4zYjCqlxwQsv4XX5Fm6IZsl31TFTyUNHoCO8o9biOxCEeXKTJjrBInLj P25jVRmkbTToM/VOVB3/ZdQBMe76u6h8/yzX8R2wXJ0OzGa44SRQyXYEltfxkOZ4qaeY 70oQ== X-Gm-Message-State: AAQBX9eiwQxG2JrDdXoFDNb9fot4l2s91+f2wduds3/LdH6P1KlFiI5n 07YzujE2xLt8AK7bNISKFfeqk1Ud01trBIPKXg== X-Google-Smtp-Source: AKy350Ynv1vxx40E2oldcA4Py+mSsLVEYWd4jHB1q+kGBD7GhiGINNV6dTkxr5askTOXvA2Ej4MyLxfovDjmFHGkMw== X-Received: from peternewman-vh.c.googlers.com ([fda3:e722:ac3:cc00:28:9cb1:c0a8:30cc]) (user=peternewman job=sendgmr) by 2002:a25:d9d6:0:b0:b80:e387:f6af with SMTP id q205-20020a25d9d6000000b00b80e387f6afmr50312ybg.2.1680184574244; Thu, 30 Mar 2023 06:56:14 -0700 (PDT) Date: Thu, 30 Mar 2023 15:55:56 +0200 In-Reply-To: <20230330135558.1019658-1-peternewman@google.com> Mime-Version: 1.0 References: <20230330135558.1019658-1-peternewman@google.com> X-Mailer: git-send-email 2.40.0.348.gf938b09366-goog Message-ID: <20230330135558.1019658-2-peternewman@google.com> Subject: [PATCH v5 1/3] x86/resctrl: Factor rdtgroup lock for multi-file ops From: Peter Newman To: reinette.chatre@intel.com, fenghua.yu@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 2.40.0.348.gf938b09366-goog