From patchwork Wed Jun 22 14:14:18 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever III X-Patchwork-Id: 12890768 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 8A62CC433EF for ; Wed, 22 Jun 2022 14:14:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1358449AbiFVOOq (ORCPT ); Wed, 22 Jun 2022 10:14:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36190 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1358381AbiFVOOd (ORCPT ); Wed, 22 Jun 2022 10:14:33 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1909639826; Wed, 22 Jun 2022 07:14:20 -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 5AECD61BDC; Wed, 22 Jun 2022 14:14:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 61D3CC34114; Wed, 22 Jun 2022 14:14:19 +0000 (UTC) Subject: [PATCH RFC 14/30] NFSD: Trace filecache LRU activity 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 10:14:18 -0400 Message-ID: <165590725828.75778.9811900270893499412.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: netdev@vger.kernel.org X-Patchwork-State: RFC 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 6bb37d3abbaa..1f65065cd325 100644 --- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -268,6 +268,18 @@ 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) { @@ -287,8 +299,7 @@ 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; @@ -451,26 +462,33 @@ 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); + trace_nfsd_file_gc_disposed(nf); return LRU_REMOVED; -out_skip: - return LRU_SKIP; } /* @@ -1040,7 +1058,7 @@ 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 c055c6361bd5..e56fe3dfa44c 100644 --- a/fs/nfsd/trace.h +++ b/fs/nfsd/trace.h @@ -851,6 +851,45 @@ 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 evicted,