From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BA6451FE469 for ; Wed, 5 Mar 2025 21:26:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741210008; cv=none; b=hjd+Ook2paKCMmxwekECAb4UQJy+2j8k/nuxLUyq8hqzueATrTCAoHwtwxodHZkeatpRxQ7+c1RLL0G0lFLRxiz3sdsInFP/J481C6phUui6X0BrcDB+ZSWxc4rgUoxjpvGNdJeLb0W0w7/682lZZMc/n54/3XDKwfwSIx9FGHo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741210008; c=relaxed/simple; bh=UZNhOMP5jyU6Kz3RFHovwlVT9Qfj8M+BG1quj7BWcIM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=oWN17l/0C6jHKQJMTMHHuO16wYHdeKyMn4PpeZ1GqCe2tmp4GPRU+i/5OCX5QQdRq7AVC3V3BV8220KHypA8B6qQKeUjXP1kXc9OY3AwFiOcMTGApKpYI539sR7fY5ScZwjE4sOSUGERInigOzHsMoOnfR/2yfmFXqQqb/I0eeU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=qdgTM/dv; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="qdgTM/dv" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.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=SfzLK33+jv5P5a/bs1K/rCWW2t4jXUCVOjx4e9QI4FA=; b=qdgTM/dveovvHQLjQRBPb+JM/k YwUZIcy2xJmV7clJ+nkuKtqTODagkS3iojwDPfi6m6KUqztkLvO+1EvPueHQyYll4xTYYj0xJ4hwE 2ngwB+OWNmX5sVhzFf9/esZ7kCEv/BhyyJyiKaskQHc1j4lrd7xKirhQ/i3+w0SSry88MGdfqikRB YjBJjeItWjDBTINfs9qtPZBahV0GBeDm8gtQtR6meSloxy4EP3s6ivUKfKF5RBXOkqzeEQsYFoU7y KOy5gltrpKmlpSPq3evTUCfuOmTJcQ1AOkfKal3kD4Zcg5immGVi76hwFW75RX+Ht3uGiETrir+UL +PDZArBA==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1tpwGE-00000006E1V-47NU; Wed, 05 Mar 2025 21:26:39 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 4038E30049D; Wed, 5 Mar 2025 22:26:38 +0100 (CET) Date: Wed, 5 Mar 2025 22:26:38 +0100 From: Peter Zijlstra To: Borislav Petkov Cc: Uros Bizjak , Dave Hansen , x86@kernel.org, linux-kernel@vger.kernel.org, Thomas Gleixner , Ingo Molnar , Dave Hansen , "H. Peter Anvin" , Linus Torvalds Subject: Re: [PATCH -tip] x86/locking/atomic: Use asm_inline for atomic locking insns Message-ID: <20250305212638.GC35526@noisy.programming.kicks-ass.net> References: <20250228123825.2729925-1-ubizjak@gmail.com> <20f1af22-71dc-4d62-9615-03030012222e@intel.com> <20250301123802.GCZ8L_qsv7-WwUwqt5@fat_crate.local> <20250305203633.GNZ8i10cVCCnhhULis@fat_crate.local> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250305203633.GNZ8i10cVCCnhhULis@fat_crate.local> On Wed, Mar 05, 2025 at 09:36:33PM +0100, Borislav Petkov wrote: > On Wed, Mar 05, 2025 at 09:54:11AM +0100, Uros Bizjak wrote: > > The -Os argument was to show the effect of the patch when the compiler > > is instructed to take care of the overall size. Giving the compiler > > -O2 and then looking at the overall size of the produced binary is > > just wrong. > > No one cares about -Os AFAICT. It might as well be non-existent. So the effect > doesn't matter. Well, more people would care if it didn't stand for -Ostupid I suppose. That is, traditionally GCC made some very questionable choices with -Os, quite horrendous code-gen.