From patchwork Wed Jun 22 14:13:12 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever X-Patchwork-Id: 12890802 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 B7107C43334 for ; Wed, 22 Jun 2022 14:15:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1358041AbiFVOPb (ORCPT ); Wed, 22 Jun 2022 10:15:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34590 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1358085AbiFVONS (ORCPT ); Wed, 22 Jun 2022 10:13:18 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DD17E1262C; Wed, 22 Jun 2022 07:13:14 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 860F061BC4; Wed, 22 Jun 2022 14:13:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9ADAEC34114; Wed, 22 Jun 2022 14:13:13 +0000 (UTC) Subject: [PATCH RFC 04/30] NFSD: Report average age of filecache items From: Chuck Lever To: linux-nfs@vger.kernel.org, netdev@vger.kernel.org Cc: david@fromorbit.com, tgraf@suug.ch, jlayton@redhat.com Date: Wed, 22 Jun 2022 10:13:12 -0400 Message-ID: <165590719265.75778.6788227290654985658.stgit@manet.1015granger.net> In-Reply-To: <165590626293.75778.9843437418112335153.stgit@manet.1015granger.net> References: <165590626293.75778.9843437418112335153.stgit@manet.1015granger.net> User-Agent: StGit/1.5.dev2+g9ce680a5 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org This is a measure of how long items stay in the filecache, to help assess how efficient the cache is. Signed-off-by: Chuck Lever --- fs/nfsd/filecache.c | 9 +++++++++ fs/nfsd/filecache.h | 1 + 2 files changed, 10 insertions(+) diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c index f735f91e576b..6f48528c6284 100644 --- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -61,6 +61,7 @@ static struct list_lru nfsd_file_lru; static long nfsd_file_lru_flags; static struct fsnotify_group *nfsd_file_fsnotify_group; static atomic_long_t nfsd_filecache_count; +static atomic_long_t nfsd_file_total_age; static struct delayed_work nfsd_filecache_laundrette; static void nfsd_file_gc(void); @@ -178,6 +179,7 @@ nfsd_file_alloc(struct inode *inode, unsigned int may, unsigned int hashval, if (nf) { INIT_HLIST_NODE(&nf->nf_node); INIT_LIST_HEAD(&nf->nf_lru); + nf->nf_birthtime = ktime_get(); nf->nf_file = NULL; nf->nf_cred = get_current_cred(); nf->nf_net = net; @@ -201,9 +203,11 @@ nfsd_file_alloc(struct inode *inode, unsigned int may, unsigned int hashval, static bool nfsd_file_free(struct nfsd_file *nf) { + s64 age = ktime_to_ms(ktime_sub(ktime_get(), nf->nf_birthtime)); bool flush = false; this_cpu_inc(nfsd_file_releases); + atomic_long_add(age, &nfsd_file_total_age); trace_nfsd_file_put_final(nf); if (nf->nf_mark) @@ -1102,6 +1106,11 @@ static int nfsd_file_cache_stats_show(struct seq_file *m, void *v) seq_printf(m, "cache hits: %lu\n", hits); seq_printf(m, "acquisitions: %lu\n", acquisitions); seq_printf(m, "releases: %lu\n", releases); + if (releases) + seq_printf(m, "mean age (ms): %ld\n", + atomic_long_read(&nfsd_file_total_age) / releases); + else + seq_printf(m, "mean age (ms): -\n"); return 0; } diff --git a/fs/nfsd/filecache.h b/fs/nfsd/filecache.h index 1da0c79a5580..d0c42619dc10 100644 --- a/fs/nfsd/filecache.h +++ b/fs/nfsd/filecache.h @@ -46,6 +46,7 @@ struct nfsd_file { refcount_t nf_ref; unsigned char nf_may; struct nfsd_file_mark *nf_mark; + ktime_t nf_birthtime; }; int nfsd_file_cache_init(void);