From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 E05486A323 for ; Mon, 8 Apr 2024 12:01:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712577669; cv=none; b=h95T/3p6s2d/yNfEV3D9kn7ckC6TzQvyU68xw9wmSp0WXT2uqWw8i8kza4CxRBWLTDozCy7eWdIIvl1a7AQgV7Z1IG2nNKYarCr+a8qMMfrab/u/4ZVclmamOAfKXtU9/5G9samVWOml9866AhUY89jIHqKe18gcuDV+qGfK5yM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712577669; c=relaxed/simple; bh=qP5DQYTs1OxFpetY7uFY8x+mv/Alr/HA1yjleOP01Rc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=O4k8+PokbnN/CSxBrH15N1OPbWzopIScQy27uXFuEXO4towG5w9+8sGK05RWH/E5IwWRokMQdoDlUnweZgJigKy62NmePIHA4FF75ZZ0ycbdaBIEt4UvnjwrYDpAwhRvxaG0GZYhwAr+dO/JopvNw8TUoCJX7uHfxqW4gsLfftU= 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=EXIXMMk0; arc=none smtp.client-ip=90.155.92.199 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="EXIXMMk0" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; 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=qP5DQYTs1OxFpetY7uFY8x+mv/Alr/HA1yjleOP01Rc=; b=EXIXMMk0sPhMuU+AeunHAZfQIf aeXvxOk60PLRESooUGcSfFaVIJJAst7M8xi3WneggNFyfiHbQ9jjD92X40jnRx8VzDtxELttNcIel A+4BIItPc7KnqhoMb0+qZ7IsShTGCuP5Dal/0mdqKwMov/HPhurmZ4hlno2UHkN4eUF8LIdQe0/QS nARmVLzaYQEm3kLtLWZ+2OFuoVHoZVFSyooGlxqjBDjjEOKUEzrJzBLbIWwBLBE76y7LU/elB0d8d uMZWcixnqZQU3+J/VUNIf+4dkfmx1GHsu4kgcKusPUOTrVAu387XKGuJ42QB35br/h6FalHDroK1O GZ1KgWkw==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.97.1 #2 (Red Hat Linux)) id 1rtng5-000000076v5-3RME; Mon, 08 Apr 2024 12:00:46 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 780BE30046F; Mon, 8 Apr 2024 14:00:45 +0200 (CEST) Date: Mon, 8 Apr 2024 14:00:45 +0200 From: Peter Zijlstra To: Abel Wu Cc: Chen Yu , Ingo Molnar , Vincent Guittot , Juri Lelli , Tim Chen , Tiwei Bie , Honglei Wang , Aaron Lu , Chen Yu , linux-kernel@vger.kernel.org, kernel test robot Subject: Re: [RFC PATCH] sched/eevdf: Return leftmost entity in pick_eevdf() if no eligible entity is found Message-ID: <20240408120045.GG21904@noisy.programming.kicks-ass.net> References: <20240226082349.302363-1-yu.c.chen@intel.com> <758ebf4e-ee84-414b-99ec-182537bcc168@bytedance.com> <63102e0a-8a16-4b1d-b8f8-d9833079c924@bytedance.com> 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: <63102e0a-8a16-4b1d-b8f8-d9833079c924@bytedance.com> On Fri, Mar 01, 2024 at 04:42:43PM +0800, Abel Wu wrote: > After a second thought, this doesn't solve the insane huge vruntime > itself. Since the immediate problem is that 'huge' number actually is > a small one, is it possible to make vruntime s64 at definition? In part that was never done because wrapping of signed types in C is UB and UBSAN used to be buggy. But also, given how it all works, it mostly doesn't matter.