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 0DE33151991 for ; Tue, 13 May 2025 01:08:58 +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=1747098539; cv=none; b=HrT0Gsja2sEr+0nZdO25JtQIqh/YG/3aOagNIJZjsn5lrrpNgmEZrcOqWO5Y58Qdb2SU4L6h119UcB9wyU5K1qzZ4sY+kc+288bHLH/tZro9yLP7xze3x8VXMZDQjNHg2PlmXoHFZ4fBuzGRAplakUltnGZsk0nP64XoB0NKWxk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747098539; c=relaxed/simple; bh=+WSu8zsEIV5f/3NjVgHOi62tswu6nL2Il99qHBko1Bc=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=IlElS+UPEHwO4EbcytRnE7qGZOgicdtNWCT3o5GJXCuuykW1dl0fvIJIUAbjAQG+EnfZSjNelzLIPRul4qZ3CZXhI+KlowomGWa82wbfJev4rEP4cg47EKmeq1MxoE6mxHT2RsuZuuMZlbpQzGaCf6TamSvY92umeqEdz/CUjrQ= 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=yC2vG1xK; 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="yC2vG1xK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 33F17C4CEE7; Tue, 13 May 2025 01:08:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1747098538; bh=+WSu8zsEIV5f/3NjVgHOi62tswu6nL2Il99qHBko1Bc=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=yC2vG1xKra/v7YQBjQAuK84gRrB0wqIPdqGIoZDrKLS/IjMJguDcf2hoXBLqlgSfy DY/R4d5SGwrReUUzbXReWugWQx+J6y4/W/rlXCiYZ0/yBIQWN86Z5Mh/Pt9lUJVNUJ MrTV2mtk6/8E5TS0Qqh/Q4p0xeW9t2zFM2QFyEC0= Date: Mon, 12 May 2025 18:08:57 -0700 From: Andrew Morton To: Cc: , , , , , Subject: Re: [PATCH linux next] taskstats: fix struct taskstats breaks backward compatibility since version 15 Message-Id: <20250512180857.59e7836290cb72dad9f3b5d3@linux-foundation.org> In-Reply-To: <20250510155413259V4JNRXxukdDgzsaL0Fo6a@zte.com.cn> References: <20250510155413259V4JNRXxukdDgzsaL0Fo6a@zte.com.cn> 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 Sat, 10 May 2025 15:54:13 +0800 (CST) wrote: > Problem > ======== > commit 658eb5ab916d ("delayacct: add delay max to record > delay peak") - adding more fields > commit f65c64f311ee ("delayacct: add delay min to record > delay peak") - adding more fields > commit b016d0873777 ("taskstats: modify taskstats version") > - version bump to 15 > > 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. > > Solution > ========= > move delay max and delay min to the end of taskstat, and bump > the version to 16 after the change Ah, there it it, thanks. I'll add cc:stable to request a backport. I'll also add Fixes: 658eb5ab916d ("delayacct: add delay max to record delay peak") Fixes: f65c64f311ee ("delayacct: add delay min to record delay peak") which is odd, but gets the point across. The patch won't exactly apply to those kernels because the version increment came later. But I think that will be OK - the patch is applicable to the v6.14 kernel.