From patchwork Fri Jul 8 18:24:12 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever X-Patchwork-Id: 12911675 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 3D6F3CCA47B for ; Fri, 8 Jul 2022 18:24:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239424AbiGHSYQ (ORCPT ); Fri, 8 Jul 2022 14:24:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44714 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239396AbiGHSYP (ORCPT ); Fri, 8 Jul 2022 14:24:15 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 787656599; Fri, 8 Jul 2022 11:24:14 -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 0F34E62474; Fri, 8 Jul 2022 18:24:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 27214C341C0; Fri, 8 Jul 2022 18:24:13 +0000 (UTC) Subject: [PATCH v3 05/32] NFSD: Report average age of filecache items From: Chuck Lever To: linux-nfs@vger.kernel.org, netdev@vger.kernel.org Cc: david@fromorbit.com, jlayton@redhat.com, tgraf@suug.ch Date: Fri, 08 Jul 2022 14:24:12 -0400 Message-ID: <165730465222.28142.1251665158880105631.stgit@klimt.1015granger.net> In-Reply-To: <165730437087.28142.6731645688073512500.stgit@klimt.1015granger.net> References: <165730437087.28142.6731645688073512500.stgit@klimt.1015granger.net> User-Agent: StGit/1.5.dev3+g9561319 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@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 | 11 ++++++++++- fs/nfsd/filecache.h | 1 + 2 files changed, 11 insertions(+), 1 deletion(-) diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c index c28e9577837d..da48c51a2bf0 100644 --- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -45,6 +45,7 @@ struct nfsd_fcache_bucket { static DEFINE_PER_CPU(unsigned long, nfsd_file_cache_hits); static DEFINE_PER_CPU(unsigned long, nfsd_file_acquisitions); static DEFINE_PER_CPU(unsigned long, nfsd_file_releases); +static DEFINE_PER_CPU(unsigned long, nfsd_file_total_age); struct nfsd_fcache_disposal { struct work_struct work; @@ -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); + this_cpu_add(nfsd_file_total_age, age); trace_nfsd_file_put_final(nf); if (nf->nf_mark) @@ -1075,7 +1079,7 @@ static int nfsd_file_cache_stats_show(struct seq_file *m, void *v) { unsigned long hits = 0, acquisitions = 0, releases = 0; unsigned int i, count = 0, longest = 0; - unsigned long lru = 0; + unsigned long lru = 0, total_age = 0; /* * No need for spinlocks here since we're not terribly interested in @@ -1096,6 +1100,7 @@ static int nfsd_file_cache_stats_show(struct seq_file *m, void *v) hits += per_cpu(nfsd_file_cache_hits, i); acquisitions += per_cpu(nfsd_file_acquisitions, i); releases += per_cpu(nfsd_file_releases, i); + total_age += per_cpu(nfsd_file_total_age, i); } seq_printf(m, "total entries: %u\n", count); @@ -1104,6 +1109,10 @@ 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", 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);