From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 E43CCA41 for ; Fri, 9 May 2025 21:17:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746825449; cv=none; b=JDRiR956WtMwgDXc8ACrt2qo7ioyGNqOkmrHO2kCtPLNI9vibVVpo0MGgOQ7ydK8NGzAAwqpDb0jyFxVhx8iHBFTQ6vN7Nn2bi2bK2b5VZnOVeHiIMbEB1OmCVtJwRHHApd1ZEuT1HMtYXn3p6KLg09gxXeB0k8+fGpDxlElEGc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746825449; c=relaxed/simple; bh=7sC1QN1fMZHI/93BJYZBh6BWm9rOd2/A9fAV0QjBoY4=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=qhnboN8LhpouPhTwlWCZx3LWsAbq1Al/LZDebtTceDlCM0lIeSW1wVUFLxq9lmzLjxlKvqa2D8Dpyw4Y+TLeg2saJfAtBK9wUdONc4CGdJBS+nsqm4aW7LtHKG1SvWjcCUqjnWd0IP44zo0LGPNZwhnQfozQKpFSBGMQT3AoXCE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=fhg5n7uM; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="fhg5n7uM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F2C0DC4CEE4; Fri, 9 May 2025 21:17:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1746825448; bh=7sC1QN1fMZHI/93BJYZBh6BWm9rOd2/A9fAV0QjBoY4=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=fhg5n7uMeHlZypqQIqYn9U5IRKKz6PBQ24S8zlTDL5Jt901kRzl8jLLjzQEt1UVWq p3QSsFBI2UzheAnLeH7Y578p0qpOA+NKkpZxHcZtvBNsBewxBM+XkyOm5OtapAHBWj ya3VWqCu7k4Ben+s2XZfWz3qVr21Zdaj4p8Z8mdY= Date: Fri, 9 May 2025 14:17:27 -0700 From: Andrew Morton To: Boian Bonev Cc: linux-kernel@vger.kernel.org, Balbir Singh , Yang Yang , Wang Yaxin , Kun Jiang , xu xin Subject: Re: Bug 220102 - struct taskstats breaks backward compatibility since version 15 Message-Id: <20250509141727.19b616d1c4a549d01656e5dd@linux-foundation.org> In-Reply-To: <5c176101cd5fd8e629b18380bf7678ea6c6a5d63.camel@devuan.org> References: <5c176101cd5fd8e629b18380bf7678ea6c6a5d63.camel@devuan.org> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) 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-Transfer-Encoding: 7bit On Fri, 09 May 2025 21:35:59 +0300 Boian Bonev wrote: > Hello! > > Since version 15 (TASKSTATS_VERSION=15) the new layout of the structure > adds fields in the middle of the structure, rendering all old software > incompatible with newer kernels and software compiled against the new > kernel headers incompatible with older kernels. Yikes. Yes, we did change the versioning but such an incompatibility seems undesirable and unnecessarily disruptive. > I think that change has to be reverted and the added fields moved to > the end of the structure. Also bumping the version to 16 after the > change is a good idea in order for the userspace software to be able to > distinguish the different formats. Yes, please send along the patch. Include the suitable Fixes: and we can backport this into the affected -stable kernels. > https://bugzilla.kernel.org/show_bug.cgi?id=220102