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=-6.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, 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 0A501C433F5 for ; Fri, 10 Sep 2021 17:00:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D55D76108B for ; Fri, 10 Sep 2021 17:00:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230294AbhIJRBX (ORCPT ); Fri, 10 Sep 2021 13:01:23 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:51356 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230097AbhIJRBW (ORCPT ); Fri, 10 Sep 2021 13:01:22 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1631293207; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=rj79Iw4i4QaQsJ7ltQNotIkO7keSLqd87PL9Qu9Znm4=; b=jMJtp7SQEDPHayYkM2AorZCvsFoRLdNWNCbu06hUe5w1vvImVvv2F1jltN/OtJAPOrs2L6 zU0o8C+FpxoijGW/eedoSanfpijUPf5+JrdMjf/j2nO5/FE9TQHRD81k40DWGXEurXZwB1 fxeo3cIsbb90awh8bv49ZbXQpSXHk/E= Received: from mail-il1-f198.google.com (mail-il1-f198.google.com [209.85.166.198]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-102--cNLNfVhMVu1AJlr9IBHjQ-1; Fri, 10 Sep 2021 13:00:06 -0400 X-MC-Unique: -cNLNfVhMVu1AJlr9IBHjQ-1 Received: by mail-il1-f198.google.com with SMTP id o12-20020a92dacc000000b00224baf7b16fso4823662ilq.12 for ; Fri, 10 Sep 2021 10:00:05 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=rj79Iw4i4QaQsJ7ltQNotIkO7keSLqd87PL9Qu9Znm4=; b=Nky+g9/i94xGiqTzQkDja0no91tAbP78G8mn8FQ3x2Eqqd28GmoJuC8b7lgS77y+7s hemBKbkgqd9bSccvAHhdDT4IbZwTSreGGnYN6ydFRG0ykAwlG0FSTYTUsgtBZ6XUDSZU LzjMuwrkhtGGFULbEUCvGNjIOMQ9bmKO834KXRfU6It4XmppyLV3m/MOsG+2Q3IiM+px scUcf1yeByVXxa0yCEmZ/BQorsLK2z/kjHBMU6MiFVRTEeqp3eEKMhpA2N9lWR6wEYGz xK/gDNlCmB0ez+u9xEVNq22lKHde4DqXlfT3XWl+GPVHZWPeINUyUMciMkXcWphQak0g Yh1g== X-Gm-Message-State: AOAM531a/Z3S1cZq/eNkA313zxE21KC42Ht1IGreI1ah5SOK9P2mfBPT t0CEx8DHgs6X80bBGcys0Ogb4ffdC7zoqAXnDoQFy5PGum+7h2CdDBNG6444SzB4z/lTdDwjPjx uAWIwZD1TUXpuTxMtr9ybVz15TIs= X-Received: by 2002:a05:6e02:805:: with SMTP id u5mr7114824ilm.223.1631293204462; Fri, 10 Sep 2021 10:00:04 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwMa2FsJnt7VdhGrWRUpRyvHvQl6Ja7v4IFRHIxtdb8D11o8kD1oZ4vTyqADRhABCegU7gb5A== X-Received: by 2002:a05:6e02:805:: with SMTP id u5mr7114809ilm.223.1631293204262; Fri, 10 Sep 2021 10:00:04 -0700 (PDT) Received: from t490s ([2607:fea8:56a2:9100::d35a]) by smtp.gmail.com with ESMTPSA id c10sm2724590ilq.77.2021.09.10.10.00.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 10 Sep 2021 10:00:03 -0700 (PDT) Date: Fri, 10 Sep 2021 13:00:02 -0400 From: Peter Xu To: nsaenzju@redhat.com Cc: linux-rt-users@vger.kernel.org, williams@redhat.com, jkacur@redhat.com Subject: Re: [PATCH 2/3] oslat: Add aarch64 support Message-ID: References: <20210908100209.118609-1-nsaenzju@redhat.com> <20210908100209.118609-2-nsaenzju@redhat.com> <466f7d726df2dfec8ac83a9d3f603439e3cec1b1.camel@redhat.com> <6a2eba408dc4260a47c1acfe743474bb39aa93bd.camel@redhat.com> <1f3916ebd3bb9d886dee56404127308a7be8098e.camel@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1f3916ebd3bb9d886dee56404127308a7be8098e.camel@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-rt-users@vger.kernel.org On Fri, Sep 10, 2021 at 04:27:05PM +0200, nsaenzju@redhat.com wrote: > My understanding is that can only happen when the expression to right of 'a' > has no dependencies with t2. And at that stage, do we really care? Well, yes, > for example if you're measuring how long it took to assign a, which is similar > to what we do: > > workload_fn workload = g.workload->w_fn; > frc(&t1) > workload() > frc(&t2) > > But in that case the compiler is forced to handle the indirect function call > and IIUC there is little optimization todo, so we're safe without barriers. Yep. > > That said, I don't feel overly confident about all this, and there is little > downside to the compiler barriers, so I'll just add them. Yep, too. IMHO that's the point (even I know it's trivial and I'm harsh :-D) - we don't have a reason to drop it if it helps us to make sure there's no surprise. Thanks, -- Peter Xu