From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F0A01C47256 for ; Fri, 1 May 2020 23:04:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D0D18216FD for ; Fri, 1 May 2020 23:04:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588374241; bh=xBoygdR4zUjiy0NTuKVFFxyj1Jciu3Ihiif7h+sn0oY=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:List-ID: From; b=ERHGN8D1Yq1z1Imii22TUVEK5u6QciUV2Hs0cZzRdsgrsrxSsvrlnDvHS1PovWK/e w2aRu/R3qqJXDYqRmOVVnfsViEoxO3pnwJexsDVicnsNjLP23v8hGqb3P43VCorl6P kJR9ntrxfSVbikt7BqeDkxah+aci77ziVNalYMP0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726401AbgEAXEB (ORCPT ); Fri, 1 May 2020 19:04:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:54794 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726045AbgEAXEA (ORCPT ); Fri, 1 May 2020 19:04:00 -0400 Received: from paulmck-ThinkPad-P72.home (50-39-105-78.bvtn.or.frontiernet.net [50.39.105.78]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E1A32208DB; Fri, 1 May 2020 23:03:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588374239; bh=xBoygdR4zUjiy0NTuKVFFxyj1Jciu3Ihiif7h+sn0oY=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=Sg+1YFkfMs3uF6hAzELiHbFynWZkgOZIRfW/jBUbTcf1dL/ixEjKvetsjWncyl43B /1tXn5KIPi5IR4gquqPvVc0ZtXBaDTwaBLPaH/voYNU8iE3fI1oSF0cELuGol0EPjL A+cVRiwZa5guNDhdpy3ywICIbvELEoeutd6BgJ6g= Received: by paulmck-ThinkPad-P72.home (Postfix, from userid 1000) id AC4BF3522B72; Fri, 1 May 2020 16:03:59 -0700 (PDT) Date: Fri, 1 May 2020 16:03:59 -0700 From: "Paul E. McKenney" To: "Uladzislau Rezki (Sony)" Cc: LKML , linux-mm@kvack.org, Andrew Morton , "Theodore Y . Ts'o" , Matthew Wilcox , Joel Fernandes , RCU , Oleksiy Avramchenko Subject: Re: [PATCH 21/24] rcu/tiny: move kvfree_call_rcu() out of header Message-ID: <20200501230359.GH7560@paulmck-ThinkPad-P72> Reply-To: paulmck@kernel.org References: <20200428205903.61704-1-urezki@gmail.com> <20200428205903.61704-22-urezki@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200428205903.61704-22-urezki@gmail.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 28, 2020 at 10:59:00PM +0200, Uladzislau Rezki (Sony) wrote: > Move inlined kvfree_call_rcu() function out of the > header file. This step is a preparation for head-less > support. > > Reviewed-by: Joel Fernandes (Google) > Signed-off-by: Uladzislau Rezki (Sony) > --- > include/linux/rcutiny.h | 6 +----- > kernel/rcu/tiny.c | 6 ++++++ > 2 files changed, 7 insertions(+), 5 deletions(-) > > diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h > index 0c6315c4a0fe..7eb66909ae1b 100644 > --- a/include/linux/rcutiny.h > +++ b/include/linux/rcutiny.h > @@ -34,11 +34,7 @@ static inline void synchronize_rcu_expedited(void) > synchronize_rcu(); > } > > -static inline void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func) > -{ > - call_rcu(head, func); > -} > - > +void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func); > void rcu_qs(void); > > static inline void rcu_softirq_qs(void) > diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c > index aa897c3f2e92..508c82faa45c 100644 > --- a/kernel/rcu/tiny.c > +++ b/kernel/rcu/tiny.c > @@ -177,6 +177,12 @@ void call_rcu(struct rcu_head *head, rcu_callback_t func) > } > EXPORT_SYMBOL_GPL(call_rcu); > > +void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func) > +{ > + call_rcu(head, func); > +} > +EXPORT_SYMBOL_GPL(kvfree_call_rcu); This increases the size of Tiny RCU. Plus in Tiny RCU, the overhead of synchronize_rcu() is exactly zero. So why not make the single-argument kvfree_call_rcu() just unconditionally do synchronize_rcu() followed by kvfree() or whatever? That should go just fine into the header file. Thanx, Paul > void __init rcu_init(void) > { > open_softirq(RCU_SOFTIRQ, rcu_process_callbacks); > -- > 2.20.1 >