From patchwork Fri Jul 8 18:25:24 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: 12911686 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 AFFB1CCA47F for ; Fri, 8 Jul 2022 18:25:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239566AbiGHSZg (ORCPT ); Fri, 8 Jul 2022 14:25:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45906 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239458AbiGHSZ1 (ORCPT ); Fri, 8 Jul 2022 14:25:27 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BE3B8823B8; Fri, 8 Jul 2022 11:25:26 -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 56DD7625AC; Fri, 8 Jul 2022 18:25:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 580BCC341C0; Fri, 8 Jul 2022 18:25:25 +0000 (UTC) Subject: [PATCH v3 16/32] NFSD: Fix the filecache LRU shrinker 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 14:25:24 -0400 Message-ID: <165730472428.28142.17571886266553271473.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 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 | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c index 6e9e186334ab..bd6ba63f69ae 100644 --- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -452,6 +452,7 @@ 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 @@ -490,7 +491,7 @@ 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)) { @@ -532,7 +533,7 @@ nfsd_file_gc(void) unsigned long ret; ret = list_lru_walk(&nfsd_file_lru, nfsd_file_lru_cb, - &dispose, LONG_MAX); + &dispose, list_lru_count(&nfsd_file_lru)); trace_nfsd_file_gc_removed(ret, list_lru_count(&nfsd_file_lru)); nfsd_file_gc_dispose_list(&dispose); }