From patchwork Wed Jun 22 14:14:31 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever X-Patchwork-Id: 12890770 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 4609DC43334 for ; Wed, 22 Jun 2022 14:15:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1357724AbiFVOPF (ORCPT ); Wed, 22 Jun 2022 10:15:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36360 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1358384AbiFVOOr (ORCPT ); Wed, 22 Jun 2022 10:14:47 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4C421393C9; Wed, 22 Jun 2022 07:14:36 -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 sin.source.kernel.org (Postfix) with ESMTPS id 85660CE206A; Wed, 22 Jun 2022 14:14:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 89C70C34114; Wed, 22 Jun 2022 14:14:32 +0000 (UTC) Subject: [PATCH RFC 16/30] NFSD: Fix the filecache LRU shrinker 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 10:14:31 -0400 Message-ID: <165590727154.75778.8699495406930751112.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 Without LRU item rotation, the shrinker visits only a few items on the end of the LRU list, and those would always be long-term OPEN files for NFSv4 workloads. That makes the filecache shrinker completely ineffective. Adopt the same strategy as the inode LRU by using LRU_ROTATE. Suggested-by: Dave Chinner Signed-off-by: Chuck Lever --- fs/nfsd/filecache.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c index 65085853cc42..deb842f45117 100644 --- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -453,6 +453,7 @@ nfsd_file_dispose_list_delayed(struct list_head *dispose) * * Return values: * %LRU_REMOVED: @item was removed from the LRU + * %LRU_ROTATED: @item is to be moved to the LRU tail * %LRU_SKIP: @item cannot be evicted */ static enum lru_status @@ -491,7 +492,7 @@ nfsd_file_lru_cb(struct list_head *item, struct list_lru_one *lru, if (test_and_clear_bit(NFSD_FILE_REFERENCED, &nf->nf_flags)) { trace_nfsd_file_gc_referenced(nf); - return LRU_SKIP; + return LRU_ROTATE; } if (!test_and_clear_bit(NFSD_FILE_HASHED, &nf->nf_flags)) { @@ -528,13 +529,14 @@ static void nfsd_file_gc_dispose_list(struct list_head *dispose) static void nfsd_file_gc(void) { + unsigned long max = list_lru_count(&nfsd_file_lru); LIST_HEAD(dispose); unsigned long ret; ret = list_lru_walk(&nfsd_file_lru, nfsd_file_lru_cb, - &dispose, LONG_MAX); + &dispose, max); this_cpu_add(nfsd_file_evictions, ret); - trace_nfsd_file_gc_evicted(ret, list_lru_count(&nfsd_file_lru)); + trace_nfsd_file_gc_evicted(ret, max); nfsd_file_gc_dispose_list(&dispose); }