From patchwork Fri Jul 8 18:25:11 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever X-Patchwork-Id: 12911684 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 C8094C43334 for ; Fri, 8 Jul 2022 18:25:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239468AbiGHSZY (ORCPT ); Fri, 8 Jul 2022 14:25:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45846 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239496AbiGHSZR (ORCPT ); Fri, 8 Jul 2022 14:25:17 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BB60A84EF5; Fri, 8 Jul 2022 11:25:15 -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 ams.source.kernel.org (Postfix) with ESMTPS id CD152B82928; Fri, 8 Jul 2022 18:25:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 36825C341C0; Fri, 8 Jul 2022 18:25:12 +0000 (UTC) Subject: [PATCH v3 14/32] NFSD: Trace filecache LRU activity 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 14:25:11 -0400 Message-ID: <165730471113.28142.1194392974048013784.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 Observe the operation of garbage collection and the lifetime of filecache items. Signed-off-by: Chuck Lever --- fs/nfsd/filecache.c | 44 +++++++++++++++++++++++++++++++------------- fs/nfsd/trace.h | 39 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 70 insertions(+), 13 deletions(-) diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c index 8ade3699664c..37373b012276 100644 --- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -267,6 +267,18 @@ nfsd_file_flush(struct nfsd_file *nf) nfsd_reset_write_verifier(net_generic(nf->nf_net, nfsd_net_id)); } +static void nfsd_file_lru_add(struct nfsd_file *nf) +{ + if (list_lru_add(&nfsd_file_lru, &nf->nf_lru)) + trace_nfsd_file_lru_add(nf); +} + +static void nfsd_file_lru_remove(struct nfsd_file *nf) +{ + if (list_lru_del(&nfsd_file_lru, &nf->nf_lru)) + trace_nfsd_file_lru_del(nf); +} + static void nfsd_file_do_unhash(struct nfsd_file *nf) { @@ -286,8 +298,7 @@ nfsd_file_unhash(struct nfsd_file *nf) { if (test_and_clear_bit(NFSD_FILE_HASHED, &nf->nf_flags)) { nfsd_file_do_unhash(nf); - if (!list_empty(&nf->nf_lru)) - list_lru_del(&nfsd_file_lru, &nf->nf_lru); + nfsd_file_lru_remove(nf); return true; } return false; @@ -450,27 +461,34 @@ nfsd_file_lru_cb(struct list_head *item, struct list_lru_one *lru, * counter. Here we check the counter and then test and clear the flag. * That order is deliberate to ensure that we can do this locklessly. */ - if (refcount_read(&nf->nf_ref) > 1) - goto out_skip; + if (refcount_read(&nf->nf_ref) > 1) { + trace_nfsd_file_gc_in_use(nf); + return LRU_SKIP; + } /* * Don't throw out files that are still undergoing I/O or * that have uncleared errors pending. */ - if (nfsd_file_check_writeback(nf)) - goto out_skip; + if (nfsd_file_check_writeback(nf)) { + trace_nfsd_file_gc_writeback(nf); + return LRU_SKIP; + } - if (test_and_clear_bit(NFSD_FILE_REFERENCED, &nf->nf_flags)) - goto out_skip; + if (test_and_clear_bit(NFSD_FILE_REFERENCED, &nf->nf_flags)) { + trace_nfsd_file_gc_referenced(nf); + return LRU_SKIP; + } - if (!test_and_clear_bit(NFSD_FILE_HASHED, &nf->nf_flags)) - goto out_skip; + if (!test_and_clear_bit(NFSD_FILE_HASHED, &nf->nf_flags)) { + trace_nfsd_file_gc_hashed(nf); + return LRU_SKIP; + } list_lru_isolate_move(lru, &nf->nf_lru, head); this_cpu_inc(nfsd_file_evictions); + trace_nfsd_file_gc_disposed(nf); return LRU_REMOVED; -out_skip: - return LRU_SKIP; } /* @@ -1037,7 +1055,7 @@ nfsd_do_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp, refcount_inc(&nf->nf_ref); __set_bit(NFSD_FILE_HASHED, &nf->nf_flags); __set_bit(NFSD_FILE_PENDING, &nf->nf_flags); - list_lru_add(&nfsd_file_lru, &nf->nf_lru); + nfsd_file_lru_add(nf); hlist_add_head_rcu(&nf->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, diff --git a/fs/nfsd/trace.h b/fs/nfsd/trace.h index 59dc5b2f4a50..1cc1133371eb 100644 --- a/fs/nfsd/trace.h +++ b/fs/nfsd/trace.h @@ -897,6 +897,45 @@ TRACE_EVENT(nfsd_file_fsnotify_handle_event, __entry->nlink, __entry->mode, __entry->mask) ); +DECLARE_EVENT_CLASS(nfsd_file_gc_class, + TP_PROTO( + const struct nfsd_file *nf + ), + TP_ARGS(nf), + TP_STRUCT__entry( + __field(void *, nf_inode) + __field(void *, nf_file) + __field(int, nf_ref) + __field(unsigned long, nf_flags) + ), + TP_fast_assign( + __entry->nf_inode = nf->nf_inode; + __entry->nf_file = nf->nf_file; + __entry->nf_ref = refcount_read(&nf->nf_ref); + __entry->nf_flags = nf->nf_flags; + ), + TP_printk("inode=%p ref=%d nf_flags=%s nf_file=%p", + __entry->nf_inode, __entry->nf_ref, + show_nf_flags(__entry->nf_flags), + __entry->nf_file + ) +); + +#define DEFINE_NFSD_FILE_GC_EVENT(name) \ +DEFINE_EVENT(nfsd_file_gc_class, name, \ + TP_PROTO( \ + const struct nfsd_file *nf \ + ), \ + TP_ARGS(nf)) + +DEFINE_NFSD_FILE_GC_EVENT(nfsd_file_lru_add); +DEFINE_NFSD_FILE_GC_EVENT(nfsd_file_lru_del); +DEFINE_NFSD_FILE_GC_EVENT(nfsd_file_gc_in_use); +DEFINE_NFSD_FILE_GC_EVENT(nfsd_file_gc_writeback); +DEFINE_NFSD_FILE_GC_EVENT(nfsd_file_gc_referenced); +DEFINE_NFSD_FILE_GC_EVENT(nfsd_file_gc_hashed); +DEFINE_NFSD_FILE_GC_EVENT(nfsd_file_gc_disposed); + DECLARE_EVENT_CLASS(nfsd_file_lruwalk_class, TP_PROTO( unsigned long removed,