From patchwork Tue Jan 25 19:00:45 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: 12724155 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 E2C55C43217 for ; Tue, 25 Jan 2022 19:01:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229780AbiAYTAx (ORCPT ); Tue, 25 Jan 2022 14:00:53 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44194 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231693AbiAYTAv (ORCPT ); Tue, 25 Jan 2022 14:00:51 -0500 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 62C76C06173B for ; Tue, 25 Jan 2022 11:00:50 -0800 (PST) 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 B524FCE1A5C for ; Tue, 25 Jan 2022 19:00:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BD621C340E0; Tue, 25 Jan 2022 19:00:46 +0000 (UTC) From: Chuck Lever To: neilb@suse.de Cc: linux-nfs@vger.kernel.org Subject: [PATCH v1 1/2] SUNRPC: Remove the .svo_enqueue_xprt method Date: Tue, 25 Jan 2022 14:00:45 -0500 Message-Id: <164313724534.3285.9750535460628123459.stgit@bazille.1015granger.net> X-Mailer: git-send-email 2.34.0 In-Reply-To: <164313706374.3285.4265550102084857832.stgit@bazille.1015granger.net> References: <164313706374.3285.4265550102084857832.stgit@bazille.1015granger.net> User-Agent: StGit/1.4 MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=5481; h=from:subject:message-id; bh=+wBuNq44qBv2nO2SDnTal3ukrlfuKJeCXxPZ75G7Q8w=; b=owEBbQKS/ZANAwAIATNqszNvZn+XAcsmYgBh8EjdAJt4QLJF6CCuWJvqjGQg2OcFTDhKpE4XRHwm FFvmE3KJAjMEAAEIAB0WIQQosuWwEobfJDzyPv4zarMzb2Z/lwUCYfBI3QAKCRAzarMzb2Z/l5SoEA C0Id5IceUkDOoJGxjpAgHRLhRNMlza0lI5ZV8SjOPLDFqmwfo4n/mt/HIx+5CNSL9XuSU+R5P1jX0K bTUU6NentVAsozY1qyFoA+YASiyI0O5G4UA3JraWD61mJHKHIIp7OgAQg62xP0k9SYCaRPWhAQkPC4 iR5gChCagUO038EEpb0p7TmdkM18x7i9nQrjQjpWFdon88aMEwIffu+sHat/w0/n1LN0EYJyByRTLf V/hOKz/tdo92aq42lDL9j6TDzSkRnzuS6BGljEeoQf32NEvLqfO9CLLoCiiLCwMgKfWENX8zC/oQQq spOwTH++XPGQv3VqFzyuEXsr+reBXodUDEqJUwkcZPKYvQ6g8NKGIBPSFxvmKbpsT8jI7OOYC77BD0 Sdf6VgvIbY8Y/45lNO5OAp5dhQMPhhdPMoLCLf2JmjIkHMQzY46q1+WpgbxdmLshSIZ8AHYrWbBpZB NeqKkRTzqYaRwrdYJFgwK9n+ccKyNRSLGdmNBpB/Z4+6xybW5PIYRSHR58oV4dkcKbkm9Xuuvx7t/t yHCpF8x16rr18EsbvfJa4TgFlD/ql92Rd9a47KF/sl7J2IZ5vH7/VSd1A1U7pbqFa4guag8Ll5CMoB QGxb38vWyg2P73TddYsgKTGtcwy/B5PGatoyYPH+lMaMh8wvfHdwFhnhFlmQ== X-Developer-Key: i=chuck.lever@oracle.com; a=openpgp; fpr=28B2E5B01286DF243CF23EFE336AB3336F667F97 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org We have never been able to track down and address the underlying cause of the performance issues with workqueue-based service support. svo_enqueue_xprt is called multiple times per RPC, so it adds instruction path length, but always ends up at the same function: svc_xprt_do_enqueue(). We do not anticipate needing this flexibility for dynamic nfsd thread management support. As a micro-optimization, remove .svo_enqueue_xprt because Spectre/Meltdown makes virtual function calls more costly. This change essentially reverts commit b9e13cdfac70 ("nfsd/sunrpc: turn enqueueing a svc_xprt into a svc_serv operation"). Signed-off-by: Chuck Lever --- fs/lockd/svc.c | 1 - fs/nfs/callback.c | 2 -- fs/nfsd/nfssvc.c | 1 - include/linux/sunrpc/svc.h | 3 --- include/linux/sunrpc/svc_xprt.h | 1 - net/sunrpc/svc_xprt.c | 10 +++++----- 6 files changed, 5 insertions(+), 13 deletions(-) diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c index 0475c5a5d061..3a05af873625 100644 --- a/fs/lockd/svc.c +++ b/fs/lockd/svc.c @@ -353,7 +353,6 @@ static struct notifier_block lockd_inet6addr_notifier = { static const struct svc_serv_ops lockd_sv_ops = { .svo_shutdown = svc_rpcb_cleanup, .svo_function = lockd, - .svo_enqueue_xprt = svc_xprt_do_enqueue, .svo_module = THIS_MODULE, }; diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c index 054cc1255fac..7a810f885063 100644 --- a/fs/nfs/callback.c +++ b/fs/nfs/callback.c @@ -234,13 +234,11 @@ static int nfs_callback_up_net(int minorversion, struct svc_serv *serv, static const struct svc_serv_ops nfs40_cb_sv_ops = { .svo_function = nfs4_callback_svc, - .svo_enqueue_xprt = svc_xprt_do_enqueue, .svo_module = THIS_MODULE, }; #if defined(CONFIG_NFS_V4_1) static const struct svc_serv_ops nfs41_cb_sv_ops = { .svo_function = nfs41_callback_svc, - .svo_enqueue_xprt = svc_xprt_do_enqueue, .svo_module = THIS_MODULE, }; diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c index b8c682b62d29..aeeac6de1f0a 100644 --- a/fs/nfsd/nfssvc.c +++ b/fs/nfsd/nfssvc.c @@ -615,7 +615,6 @@ static int nfsd_get_default_max_blksize(void) static const struct svc_serv_ops nfsd_thread_sv_ops = { .svo_shutdown = nfsd_last_thread, .svo_function = nfsd, - .svo_enqueue_xprt = svc_xprt_do_enqueue, .svo_module = THIS_MODULE, }; diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h index f35c22b3355f..6ef9c1cafd0b 100644 --- a/include/linux/sunrpc/svc.h +++ b/include/linux/sunrpc/svc.h @@ -61,9 +61,6 @@ struct svc_serv_ops { /* function for service threads to run */ int (*svo_function)(void *); - /* queue up a transport for servicing */ - void (*svo_enqueue_xprt)(struct svc_xprt *); - /* optional module to count when adding threads. * Thread function must call module_put_and_kthread_exit() to exit. */ diff --git a/include/linux/sunrpc/svc_xprt.h b/include/linux/sunrpc/svc_xprt.h index 571f605bc91e..a3ba027fb4ba 100644 --- a/include/linux/sunrpc/svc_xprt.h +++ b/include/linux/sunrpc/svc_xprt.h @@ -131,7 +131,6 @@ int svc_create_xprt(struct svc_serv *, const char *, struct net *, const int, const unsigned short, int, const struct cred *); void svc_xprt_received(struct svc_xprt *xprt); -void svc_xprt_do_enqueue(struct svc_xprt *xprt); void svc_xprt_enqueue(struct svc_xprt *xprt); void svc_xprt_put(struct svc_xprt *xprt); void svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt); diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c index b21ad7994147..9fce4f7774bb 100644 --- a/net/sunrpc/svc_xprt.c +++ b/net/sunrpc/svc_xprt.c @@ -32,6 +32,7 @@ static int svc_deferred_recv(struct svc_rqst *rqstp); static struct cache_deferred_req *svc_defer(struct cache_req *req); static void svc_age_temp_xprts(struct timer_list *t); static void svc_delete_xprt(struct svc_xprt *xprt); +static void svc_xprt_do_enqueue(struct svc_xprt *xprt); /* apparently the "standard" is that clients close * idle connections after 5 minutes, servers after @@ -266,12 +267,12 @@ void svc_xprt_received(struct svc_xprt *xprt) } /* As soon as we clear busy, the xprt could be closed and - * 'put', so we need a reference to call svc_enqueue_xprt with: + * 'put', so we need a reference to call svc_xprt_do_enqueue with: */ svc_xprt_get(xprt); smp_mb__before_atomic(); clear_bit(XPT_BUSY, &xprt->xpt_flags); - xprt->xpt_server->sv_ops->svo_enqueue_xprt(xprt); + svc_xprt_do_enqueue(xprt); svc_xprt_put(xprt); } EXPORT_SYMBOL_GPL(svc_xprt_received); @@ -423,7 +424,7 @@ static bool svc_xprt_ready(struct svc_xprt *xprt) return false; } -void svc_xprt_do_enqueue(struct svc_xprt *xprt) +static void svc_xprt_do_enqueue(struct svc_xprt *xprt) { struct svc_pool *pool; struct svc_rqst *rqstp = NULL; @@ -467,7 +468,6 @@ void svc_xprt_do_enqueue(struct svc_xprt *xprt) put_cpu(); trace_svc_xprt_enqueue(xprt, rqstp); } -EXPORT_SYMBOL_GPL(svc_xprt_do_enqueue); /* * Queue up a transport with data pending. If there are idle nfsd @@ -478,7 +478,7 @@ void svc_xprt_enqueue(struct svc_xprt *xprt) { if (test_bit(XPT_BUSY, &xprt->xpt_flags)) return; - xprt->xpt_server->sv_ops->svo_enqueue_xprt(xprt); + svc_xprt_do_enqueue(xprt); } EXPORT_SYMBOL_GPL(svc_xprt_enqueue);