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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 7D00BC43387 for ; Thu, 17 Jan 2019 08:13:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4592420859 for ; Thu, 17 Jan 2019 08:13:34 +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="Gb3Z2a5/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729531AbfAQINc (ORCPT ); Thu, 17 Jan 2019 03:13:32 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:42296 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726819AbfAQINb (ORCPT ); Thu, 17 Jan 2019 03:13:31 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=Y4uxIJ+NmKS4i1/qDFOJcjGOWHA5fYMzGvsJDpvLNMk=; b=Gb3Z2a5/SgLc7y6cDeKRsD6/b UGyiZaiVvFOZBwXSKjGIYRsQNt6oZrxmzioVR9lNQDxgqinTD+S5lDERHN1ve0DaliP4AwKyITgCM A+UCHwHAEEHzqwPGKMUytNEjA1IxycEObBOFm2SKjW9QKxa4IhnfAgppSs+foYr4ZPx9gJsX9BStQ sBlgLXbY4Pr9Ohz+5g94z2E7eFXauAu5PKKbSLuqAPScIthGvavDjNylmSQvJQsT1cvRNkkMqFHVK cfKQWe6maqz0v82+VU2+yFeXHBL3SWB5DG6pWbwzELav8dUpHCYgZnkf3mU7rYJrOR8kw1h8KeQfb TUhbIbMqQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1gk2nc-0005l8-6v; Thu, 17 Jan 2019 08:13:16 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 403C2202647C2; Thu, 17 Jan 2019 09:13:14 +0100 (CET) Date: Thu, 17 Jan 2019 09:13:14 +0100 From: Peter Zijlstra To: Johannes Weiner Cc: Suren Baghdasaryan , Greg Kroah-Hartman , Tejun Heo , lizefan@huawei.com, axboe@kernel.dk, dennis@kernel.org, Dennis Zhou , Ingo Molnar , Andrew Morton , Jonathan Corbet , cgroups@vger.kernel.org, linux-mm , linux-doc@vger.kernel.org, LKML , kernel-team@android.com Subject: Re: [PATCH v2 5/5] psi: introduce psi monitor Message-ID: <20190117081314.GD10486@hirez.programming.kicks-ass.net> References: <20190110220718.261134-1-surenb@google.com> <20190110220718.261134-6-surenb@google.com> <20190114102137.GB14054@worktop.programming.kicks-ass.net> <20190116132446.GF10803@hirez.programming.kicks-ass.net> <20190116191728.GA1380@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190116191728.GA1380@cmpxchg.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 16, 2019 at 02:17:28PM -0500, Johannes Weiner wrote: > > > Also, you probably want to use atomic_t for g->polling, because we > > > (sadly) have architectures where regular stores and atomic ops don't > > > work 'right'. > > > > Oh, I see. Will do. Thanks! > > Yikes, that's news to me too. Good to know. See Documentation/atomic_t.txt, specifically the atomic_set() part in SEMANTICS. Archs that suffer this include (but are not limited to): parisc, sparc32-smp, something arc. And yes, I would dearly love to kill all SMP support for architectures like that..