From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B1495C4BA12 for ; Wed, 26 Feb 2020 16:15:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 85CFC24670 for ; Wed, 26 Feb 2020 16:15:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="E5B24mbs" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728610AbgBZQPi (ORCPT ); Wed, 26 Feb 2020 11:15:38 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:51956 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728373AbgBZQPh (ORCPT ); Wed, 26 Feb 2020 11:15:37 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1582733737; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:in-reply-to:in-reply-to:references:references; bh=plSY3/ieBBIb+uqAgd5rkUQMsog86fQPx4J35UFU/bc=; b=E5B24mbs4NAB4uNAp+xMnYWDt2c/RQyY3O1OtCOwDUvym0yILB+SVahps7umRKAptHFGTE M95aDP1cMFMdn4yLqeIZ/OQrctHVDCcqnthYJjolz9+egTWDUlQKuZvF2Db91jQKOIPY4H Gu/BfcLmqQrSUYDVA6JLIm1vzsk/5Po= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-182-Hj-vPNxaMieEVX_Boex0rg-1; Wed, 26 Feb 2020 11:15:33 -0500 X-MC-Unique: Hj-vPNxaMieEVX_Boex0rg-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 289DADBF2; Wed, 26 Feb 2020 16:15:31 +0000 (UTC) Received: from llong.com (dhcp-17-59.bos.redhat.com [10.18.17.59]) by smtp.corp.redhat.com (Postfix) with ESMTP id 536B860BE1; Wed, 26 Feb 2020 16:15:25 +0000 (UTC) From: Waiman Long To: Alexander Viro , Jonathan Corbet , Luis Chamberlain , Kees Cook , Iurii Zaikin Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-doc@vger.kernel.org, Mauro Carvalho Chehab , Eric Biggers , Dave Chinner , Eric Sandeen , Waiman Long Subject: [PATCH 07/11] fs/dcache: Add static key negative_reclaim_enable Date: Wed, 26 Feb 2020 11:14:00 -0500 Message-Id: <20200226161404.14136-8-longman@redhat.com> In-Reply-To: <20200226161404.14136-1-longman@redhat.com> References: <20200226161404.14136-1-longman@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Add a static_key negative_reclaim_enable to optimize the default case where negative dentry directory limit "dentry-dir-max" is not set. Signed-off-by: Waiman Long --- fs/dcache.c | 30 ++++++++++++++++++++++++++++-- kernel/sysctl.c | 3 ++- 2 files changed, 30 insertions(+), 3 deletions(-) diff --git a/fs/dcache.c b/fs/dcache.c index c5364c2ed5d8..149c0a6c1a6e 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -32,6 +32,7 @@ #include #include #include +#include #include "internal.h" #include "mount.h" @@ -134,11 +135,13 @@ int dcache_dentry_dir_max_sysctl __read_mostly; EXPORT_SYMBOL_GPL(dcache_dentry_dir_max_sysctl); static LLIST_HEAD(negative_reclaim_list); +static DEFINE_STATIC_KEY_FALSE(negative_reclaim_enable); static void negative_reclaim_check(struct dentry *parent); static void negative_reclaim_workfn(struct work_struct *work); static DECLARE_WORK(negative_reclaim_work, negative_reclaim_workfn); #if defined(CONFIG_SYSCTL) && defined(CONFIG_PROC_FS) +proc_handler proc_dcache_dentry_dir_max; /* * Here we resort to our own counters instead of using generic per-cpu counters @@ -188,6 +191,27 @@ int proc_nr_dentry(struct ctl_table *table, int write, void __user *buffer, dentry_stat.nr_negative = get_nr_dentry_negative(); return proc_doulongvec_minmax(table, write, buffer, lenp, ppos); } + +/* + * Sysctl proc handler for dcache_dentry_dir_max_sysctl + */ +int proc_dcache_dentry_dir_max(struct ctl_table *ctl, int write, + void __user *buffer, size_t *lenp, loff_t *ppos) +{ + int old = dcache_dentry_dir_max_sysctl; + int ret; + + ret = proc_dointvec_minmax(ctl, write, buffer, lenp, ppos); + + if (!write || ret || (dcache_dentry_dir_max_sysctl == old)) + return ret; + + if (!old && dcache_dentry_dir_max_sysctl) + static_branch_enable(&negative_reclaim_enable); + else if (old && !dcache_dentry_dir_max_sysctl) + static_branch_disable(&negative_reclaim_enable); + return 0; +} #endif /* @@ -876,7 +900,8 @@ void dput(struct dentry *dentry) if (likely(retain_dentry(dentry))) { struct dentry *neg_parent = NULL; - if (d_is_negative(dentry)) { + if (static_branch_unlikely(&negative_reclaim_enable) && + d_is_negative(dentry)) { neg_parent = dentry->d_parent; rcu_read_lock(); } @@ -886,7 +911,8 @@ void dput(struct dentry *dentry) * Negative dentry reclaim check is only done when * a negative dentry is being put into a LRU list. */ - if (neg_parent) + if (static_branch_unlikely(&negative_reclaim_enable) && + neg_parent) negative_reclaim_check(neg_parent); return; } diff --git a/kernel/sysctl.c b/kernel/sysctl.c index cd0a83ff1029..9a4b0a1376e8 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -119,6 +119,7 @@ extern unsigned int sysctl_nr_open_min, sysctl_nr_open_max; extern int sysctl_nr_trim_pages; #endif extern int dcache_dentry_dir_max_sysctl; +extern proc_handler proc_dcache_dentry_dir_max; /* Constants used for minimum and maximum */ #ifdef CONFIG_LOCKUP_DETECTOR @@ -1956,7 +1957,7 @@ static struct ctl_table fs_table[] = { .data = &dcache_dentry_dir_max_sysctl, .maxlen = sizeof(dcache_dentry_dir_max_sysctl), .mode = 0644, - .proc_handler = proc_dointvec_minmax, + .proc_handler = proc_dcache_dentry_dir_max, .extra1 = &zero, }, { } -- 2.18.1