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 2A9E634B681 for ; Tue, 21 Oct 2025 17:19:00 +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=1761067141; cv=none; b=STaZhqK09X6QHzaGKAX+CjV8hKUvaRXU1pbigEn4F9iqNKxpwzl9lhlCGZl6WMtMzpPIXJ/uE3gQfMLZKrWtmKOuRFm9d4E7Mh8vGyyiAgHNm/dT42xTpCXq5tzKaKaRTZAooB0qstoS58F3EpXJc9H7RF2DVmYTW2tdU//udFc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761067141; c=relaxed/simple; bh=hKFTNt2WYF5lClgPeowGyL6JH/q7f2NilKmKdBlQD8k=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=kh8MfQ6LPuU3TUk0j+W5CTHaSKULN2CWoSr/3jPSp7PhMwJj664wAdUfcX19ZdYIcS7o4O52N4eUMKH9d4VqCr/COWUM48AzNJG96GP6EbidprC8SQrqROvR1RX9b/vkiwyB9FZ99DRo1EXmjgUgJx4jN70urLMaT0WAw+4JNeY= 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=pUk32OED; 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="pUk32OED" 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=l4qh635JwtraH9+156UkCtjfpNcMPfZvE9SSt+2WcXk=; b=pUk32OEDfuLKAVrr1q8dOnJ9a8 PwSCurTdykUHHfA+NCXYfQlN/70nN+hfHl+vySZUOlA2vmVHTuqDK+c21nSMOzQh9Jo8/OrzCe3KF Qmt4w1Ke/lARvwRCNuEo9Qt2NyJEW0Sp8D+zRQD3eyv8h4jM6MH4PU6130JLVosbRNXqHVYMW84Ov U59Stcn2jmnYqsfpC3nJ5Pomt4w66ggczGhPXI4+Ix2osX1dl0fX8rfRnvS7wBkHycKvoY7uObtIs GBjFnEuLbZHCDQgoT/UwSg2RZ0ktSLD2AoDjdNqIZIcqbV6jpCyXi2gEejmkinAo5ZA55s0PCZtOf xvzpugXA==; 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 #2 (Red Hat Linux)) id 1vBG0d-0000000DsXg-1PF1; Tue, 21 Oct 2025 17:18:57 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 7915F3030BC; Mon, 20 Oct 2025 12:28:14 +0200 (CEST) Date: Mon, 20 Oct 2025 12:28:14 +0200 From: Peter Zijlstra To: Steven Rostedt Cc: jpoimboe@kernel.org, rostedt@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 10/12] unwind: Simplify unwind_user_next_fp() alignment check Message-ID: <20251020102814.GN3419281@noisy.programming.kicks-ass.net> References: <20250924075948.579302904@infradead.org> <20250924080119.497867836@infradead.org> <20251001115524.24542fd8@gandalf.local.home> 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: <20251001115524.24542fd8@gandalf.local.home> On Wed, Oct 01, 2025 at 11:55:24AM -0400, Steven Rostedt wrote: > On Wed, 24 Sep 2025 09:59:58 +0200 > Peter Zijlstra wrote: > > I would add a change log. Something like: > > sizeof(long) is 4 or 8. Where 4 = 1 << 2 and 8 = 1 << 3. > Calculating shift to be 2 or 3 and then passing that variable into > (1 << shift) is the same as just using sizeof(long). I've made it: "2^log_2(n) == n". I find it very hard to spend that many words on something this trivial :-)