From patchwork Tue Nov 17 11:52:35 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 7636511 Return-Path: X-Original-To: patchwork-linux-nfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 15B229F1D3 for ; Tue, 17 Nov 2015 11:54:57 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id F2F13204E2 for ; Tue, 17 Nov 2015 11:54:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E8466204EC for ; Tue, 17 Nov 2015 11:54:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752096AbbKQLyv (ORCPT ); Tue, 17 Nov 2015 06:54:51 -0500 Received: from mail-qg0-f43.google.com ([209.85.192.43]:35690 "EHLO mail-qg0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753412AbbKQLxc (ORCPT ); Tue, 17 Nov 2015 06:53:32 -0500 Received: by qgec40 with SMTP id c40so3391317qge.2 for ; Tue, 17 Nov 2015 03:53:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=poochiereds_net.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=QLwkbTI2bGl6Je4MlhB6Elg6mb/XlmKZLJ01fM9xgSE=; b=l2lETZUg4JVTcPJS2mYtkHKb55C+ADHq61IyTgFiuS/Wa6Rr9oUCuWptBe1JZ5zasT lVVbIA6BKdtKvXb0HY4ssSaHLjUoB6PQMHMctqFwZcpW9ww5bnOmDnfH9bEwiRQ4UqIl qaNxvrhxacwScP/Z5WV2ovORs0woi5XvLg0+8cXHXAN9On1aZx4kcOQdQLgVBU5AoAoF DA7u7T1vnetlo760PuV/gnOjK9YGJL7I68MfyBm0rtxFCk/96LJxN0u9ZJf8GRWpppel u294HiWbbx2VK0Zkjh77CYvfi1bOazRwQ9oR/ZzhNyb/FOgO/dKpU1N7ofPU8tHoIgNc +lvg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=QLwkbTI2bGl6Je4MlhB6Elg6mb/XlmKZLJ01fM9xgSE=; b=klKB7s8zzA/FwUKfh5unXc+5fCySoGgENRP2hIGDxuZhabN6XLkaOPOzpZip/R9k7e kXpsCccWl/gLcYKJm8NLZ5+wYmhLWh3qphJHLuEHD4tecRXg8NApt+pfxf0nyWfqr9Kl AEU0bxWiUP9hgwscl6kxlMqCpfN2K8Gu9Ow/ZHzJXk8tPX/UBDwGCjSEaOv342ED8cPN DKvwz8P7ttb/LSpSRzxt2gHHyxVuZbKdIVwglwqPhyjMqfwbnZLVMjiH4kOUyXOkTx4+ DL3cSjZkPpG90kuUMq3h5NWijnxAC7idxPu6SkgNlORwaBEwTyHaeYKeLL0DXBvAppd9 h7ww== X-Gm-Message-State: ALoCoQme7bgX64J3DJYf6knsrwlIzsOS8Sb/64DY3G+LMPxQZSrtdSi/oohM8LQG9mWeh4snl0yd X-Received: by 10.140.253.135 with SMTP id y129mr43992272qhc.20.1447761211328; Tue, 17 Nov 2015 03:53:31 -0800 (PST) Received: from tlielax.poochiereds.net ([2606:a000:1125:4075::d5a]) by smtp.googlemail.com with ESMTPSA id w10sm1583910qhc.16.2015.11.17.03.53.30 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 17 Nov 2015 03:53:30 -0800 (PST) From: Jeff Layton X-Google-Original-From: Jeff Layton To: bfields@fieldses.org, trond.myklebust@primarydata.com Cc: linux-nfs@vger.kernel.org, Eric Paris , Alexander Viro , linux-fsdevel@vger.kernel.org Subject: [PATCH v1 13/38] nfsd: keep some rudimentary stats on nfsd_file cache Date: Tue, 17 Nov 2015 06:52:35 -0500 Message-Id: <1447761180-4250-14-git-send-email-jeff.layton@primarydata.com> X-Mailer: git-send-email 2.4.3 In-Reply-To: <1447761180-4250-1-git-send-email-jeff.layton@primarydata.com> References: <1447761180-4250-1-git-send-email-jeff.layton@primarydata.com> Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Spam-Status: No, score=-7.4 required=5.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,RP_MATCHES_RCVD,T_DKIM_INVALID,UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Per chain count and max length, protected by the per-chain spinlock. When the file is read, we walk the array of buckets and fetch the count from each. Signed-off-by: Jeff Layton --- fs/nfsd/filecache.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++++++- fs/nfsd/filecache.h | 1 + fs/nfsd/nfsctl.c | 10 ++++++++++ 3 files changed, 62 insertions(+), 1 deletion(-) diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c index f6c4480c5d78..f6adccc6f740 100644 --- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -11,6 +11,7 @@ #include #include #include +#include #include "vfs.h" #include "nfsd.h" @@ -30,8 +31,12 @@ struct nfsd_fcache_bucket { struct hlist_head nfb_head; spinlock_t nfb_lock; + unsigned int nfb_count; + unsigned int nfb_maxcount; }; +static DEFINE_PER_CPU(unsigned long, nfsd_file_cache_hits); + static struct kmem_cache *nfsd_file_slab; static struct kmem_cache *nfsd_file_mark_slab; static struct nfsd_fcache_bucket *nfsd_file_hashtbl; @@ -172,6 +177,7 @@ nfsd_file_unhash(struct nfsd_file *nf) trace_nfsd_file_unhash(nf); if (test_bit(NFSD_FILE_HASHED, &nf->nf_flags)) { + --nfsd_file_hashtbl[nf->nf_hashval].nfb_count; clear_bit(NFSD_FILE_HASHED, &nf->nf_flags); hlist_del_rcu(&nf->nf_node); list_lru_del(&nfsd_file_lru, &nf->nf_lru); @@ -562,8 +568,10 @@ retry: rcu_read_lock(); nf = nfsd_file_find_locked(inode, may_flags, hashval); rcu_read_unlock(); - if (nf) + if (nf) { + this_cpu_inc(nfsd_file_cache_hits); goto wait_for_construction; + } if (!new) { new = nfsd_file_alloc(inode, may_flags, hashval); @@ -584,11 +592,15 @@ retry: list_lru_add(&nfsd_file_lru, &new->nf_lru); hlist_add_head_rcu(&new->nf_node, &nfsd_file_hashtbl[hashval].nfb_head); + ++nfsd_file_hashtbl[hashval].nfb_count; + nfsd_file_hashtbl[hashval].nfb_maxcount = max(nfsd_file_hashtbl[hashval].nfb_maxcount, + nfsd_file_hashtbl[hashval].nfb_count); spin_unlock(&nfsd_file_hashtbl[hashval].nfb_lock); nf = new; new = NULL; goto open_file; } + this_cpu_inc(nfsd_file_cache_hits); spin_unlock(&nfsd_file_hashtbl[hashval].nfb_lock); wait_for_construction: @@ -666,3 +678,41 @@ open_file: wake_up_bit(&nf->nf_flags, NFSD_FILE_PENDING); goto out; } + +/* + * Note that fields may be added, removed or reordered in the future. Programs + * scraping this file for info should test the labels to ensure they're + * getting the correct field. + */ +static int nfsd_file_cache_stats_show(struct seq_file *m, void *v) +{ + unsigned int i, count = 0, longest = 0; + unsigned long hits = 0; + + /* + * No need for spinlocks here since we're not terribly interested in + * accuracy. We do take the nfsd_mutex simply to ensure that we + * don't end up racing with server shutdown + */ + mutex_lock(&nfsd_mutex); + if (nfsd_file_hashtbl) { + for (i = 0; i < NFSD_FILE_HASH_SIZE; i++) { + count += nfsd_file_hashtbl[i].nfb_count; + longest = max(longest, nfsd_file_hashtbl[i].nfb_count); + } + } + mutex_unlock(&nfsd_mutex); + + for_each_possible_cpu(i) + hits += per_cpu(nfsd_file_cache_hits, i); + + seq_printf(m, "total entries: %u\n", count); + seq_printf(m, "longest chain: %u\n", longest); + seq_printf(m, "cache hits: %lu\n", hits); + return 0; +} + +int nfsd_file_cache_stats_open(struct inode *inode, struct file *file) +{ + return single_open(file, nfsd_file_cache_stats_show, NULL); +} diff --git a/fs/nfsd/filecache.h b/fs/nfsd/filecache.h index a045c7fe3655..756aea5431da 100644 --- a/fs/nfsd/filecache.h +++ b/fs/nfsd/filecache.h @@ -40,4 +40,5 @@ struct nfsd_file *nfsd_file_get(struct nfsd_file *nf); void nfsd_file_close_inode_sync(struct inode *inode); __be32 nfsd_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp, unsigned int may_flags, struct nfsd_file **nfp); +int nfsd_file_cache_stats_open(struct inode *, struct file *); #endif /* _FS_NFSD_FILECACHE_H */ diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index 9690cb4dd588..eff44a277f70 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -22,6 +22,7 @@ #include "state.h" #include "netns.h" #include "pnfs.h" +#include "filecache.h" /* * We have a single directory with several nodes in it. @@ -36,6 +37,7 @@ enum { NFSD_Threads, NFSD_Pool_Threads, NFSD_Pool_Stats, + NFSD_File_Cache_Stats, NFSD_Reply_Cache_Stats, NFSD_Versions, NFSD_Ports, @@ -220,6 +222,13 @@ static const struct file_operations pool_stats_operations = { .owner = THIS_MODULE, }; +static struct file_operations file_cache_stats_operations = { + .open = nfsd_file_cache_stats_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + static struct file_operations reply_cache_stats_operations = { .open = nfsd_reply_cache_stats_open, .read = seq_read, @@ -1138,6 +1147,7 @@ static int nfsd_fill_super(struct super_block * sb, void * data, int silent) [NFSD_Threads] = {"threads", &transaction_ops, S_IWUSR|S_IRUSR}, [NFSD_Pool_Threads] = {"pool_threads", &transaction_ops, S_IWUSR|S_IRUSR}, [NFSD_Pool_Stats] = {"pool_stats", &pool_stats_operations, S_IRUGO}, + [NFSD_File_Cache_Stats] = {"file_cache_stats", &file_cache_stats_operations, S_IRUGO}, [NFSD_Reply_Cache_Stats] = {"reply_cache_stats", &reply_cache_stats_operations, S_IRUGO}, [NFSD_Versions] = {"versions", &transaction_ops, S_IWUSR|S_IRUSR}, [NFSD_Ports] = {"portlist", &transaction_ops, S_IWUSR|S_IRUGO},