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=-3.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 0DE4BC433E0 for ; Wed, 20 May 2020 10:54:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CB221207D3 for ; Wed, 20 May 2020 10:54:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="AF783d4C" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726857AbgETKyB (ORCPT ); Wed, 20 May 2020 06:54:01 -0400 Received: from merlin.infradead.org ([205.233.59.134]:54766 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726403AbgETKyA (ORCPT ); Wed, 20 May 2020 06:54:00 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=Yq27b7ObxQImP0IhKad7is0YDQIJNP7DgoreIpDDvKc=; b=AF783d4CouNOb7lX75QxKlZqNP tnmu5QM0kAImJUE9qD/nFznrBVnuXzCl9+Os0lnMhrDYQ604j+8R0UN08wOF2Saxe6xwoyKf7y8Bo TX8aJhSDoDbmlGZPwdWJSlk6RudKXvsN0ebzN28bY45f5MPTa1Acgkryx+qphd5qEYltr2YzDKtz5 9/Rx7hGRPuqiuDZ4I8uMJT8xk4qfoXas6DFfp/0RqMBHr0lH6ibyg+dMue6Nbrps1r77+PHO1RPZ6 HuFyC1AgAahCjEdIOxsJWgMnjRz6ZG+1SsXoL6gX+I2P76EoDpWd38LrPxuOFdZmA4kzjO2Dhe9b6 RwuT/rVg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jbMLk-0005wq-6A; Wed, 20 May 2020 10:53:27 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id A043A30067C; Wed, 20 May 2020 12:53:22 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 5989029D896D4; Wed, 20 May 2020 12:53:22 +0200 (CEST) Date: Wed, 20 May 2020 12:53:22 +0200 From: Peter Zijlstra To: Sebastian Andrzej Siewior Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Steven Rostedt , Will Deacon , Thomas Gleixner , "Paul E . McKenney" , Linus Torvalds , Andrew Morton , linux-mm@kvack.org Subject: Re: [PATCH 4/8] mm/swap: Use local_lock for protection Message-ID: <20200520105322.GG317569@hirez.programming.kicks-ass.net> References: <20200519201912.1564477-1-bigeasy@linutronix.de> <20200519201912.1564477-5-bigeasy@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200519201912.1564477-5-bigeasy@linutronix.de> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 19, 2020 at 10:19:08PM +0200, Sebastian Andrzej Siewior wrote: > diff --git a/mm/swap.c b/mm/swap.c > index bf9a79fed62d7..03c97d15fcd69 100644 > --- a/mm/swap.c > +++ b/mm/swap.c > @@ -44,8 +44,14 @@ > /* How many pages do we try to swap or page in/out together? */ > int page_cluster; > > -static DEFINE_PER_CPU(struct pagevec, lru_add_pvec); > + > +/* Protecting lru_rotate_pvecs */ > +static DEFINE_LOCAL_LOCK(rotate_lock); > static DEFINE_PER_CPU(struct pagevec, lru_rotate_pvecs); > + > +/* Protecting the following struct pagevec */ > +DEFINE_LOCAL_LOCK(swapvec_lock); > +static DEFINE_PER_CPU(struct pagevec, lru_add_pvec); > static DEFINE_PER_CPU(struct pagevec, lru_deactivate_file_pvecs); > static DEFINE_PER_CPU(struct pagevec, lru_deactivate_pvecs); > static DEFINE_PER_CPU(struct pagevec, lru_lazyfree_pvecs); So personally I'd prefer to have this look like: struct lru_vecs { struct local_lock lock; struct pagevec add; struct pagevec rotate; struct pagevec deact_file; struct pagevec deact; struct pagevec lazyfree; #ifdef CONFIG_SMP struct pagevec active; #endif }; DEFINE_PER_CPU(struct lru_pvec, lru_pvec); or something, but I realize that is a lot of churn (although highly automated), so I'll leave that to the mm folks.