From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta-64-226.siemens.flowmailer.net (mta-64-226.siemens.flowmailer.net [185.136.64.226]) (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 D55FE384CFD for ; Fri, 10 Jul 2026 16:01:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.136.64.226 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783699294; cv=none; b=l0B3kJnxmuDegwVfFI0JN/NrUC0pHsatHoo/FQ2YTdu+NVpn9nxCukgZFNoU4i5Em0fXsz5f0ZRP91kVDXq3lyXWvII5TqxAvM6j21DOLSHY75ReYzRB0kJ+wq1/w640Jks8OKccezmw9U/ersd6zV3AJKjzKZTFLTDdpg55t7Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783699294; c=relaxed/simple; bh=5r4Pa0QxyR4IG7q9f+DWCy4twslM4Pd8WTvTt319zwg=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=HWW0yeIt7jKh42nMP9oYDI9Gu7q6DVo8EzsiRs1wqW4/1gMeL9qYfS0uSrHtPMD/oe0q5DQy1mxJQ6xkI47BTMNj0BVsUkjIEzDLLGpL8+ugkdmzLSZfVWKOiFENdvg/HomGh81q/u+Zl7pGssEOt+lSDW/vg1xYHoyplk0EtmI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=siemens.com; spf=pass smtp.mailfrom=rts-flowmailer.siemens.com; dkim=pass (2048-bit key) header.d=siemens.com header.i=florian.bezdeka@siemens.com header.b=b2mgrImW; arc=none smtp.client-ip=185.136.64.226 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=siemens.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=rts-flowmailer.siemens.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=siemens.com header.i=florian.bezdeka@siemens.com header.b="b2mgrImW" Received: by mta-64-226.siemens.flowmailer.net with ESMTPSA id 2026071016012103a7636255000207e9 for ; Fri, 10 Jul 2026 18:01:21 +0200 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; s=fm1; d=siemens.com; i=florian.bezdeka@siemens.com; h=Date:From:Subject:To:Message-ID:MIME-Version:Content-Type:Content-Transfer-Encoding:Cc:References:In-Reply-To; bh=5r4Pa0QxyR4IG7q9f+DWCy4twslM4Pd8WTvTt319zwg=; b=b2mgrImWtAiC+ILwnGav/2x+yjhpy+MNSscBG8oPq4LWRYF74CK/xfAMIaxgtyyVKgFhMs L1vFYrapYS/pHWZOmIwxlhICYikuXQT3G4MCv1/vJlM03TU+m+Xch5scP806KlQzNSj2val4 0CUwVO1pUuA1HzhYmb2iQMPHRSNpWWpQkvoCB0sCb/z80Bd8eMSIN4n/sbR3r55zhQLOqDRp 0cN79zXhPjVGjifTOGQ5gZF2/9/+wuK53Pg22BOGWJKol15t8L2agnL3fz+3t8p1nWsaxLe4 zmiBmozN/khG040Dh7zAXHsYEsrCNL268EVDY08c9TU9hccIneK7jrdQ==; Message-ID: Subject: Re: [RFC PATCH] sysfs: Add /sys/kernel/realtime entry From: Florian Bezdeka To: Steven Rostedt Cc: Sebastian Andrzej Siewior , Greg Kroah-Hartman , driver-core@lists.linux.dev, linux-rt-devel@lists.linux.dev, linux-rt-users@vger.kernel.org, "Rafael J. Wysocki" , Arnd Bergmann , Clark Williams , Danilo Krummrich , Peter Zijlstra , Thomas Gleixner , Jan Kiszka Date: Fri, 10 Jul 2026 18:01:20 +0200 In-Reply-To: <20260710115145.32729a7c@gandalf.local.home> References: <20260709143108.UYeCUUcd@linutronix.de> <2026070922-kilowatt-matador-5e1c@gregkh> <20260709152214.rH1O_8SM@linutronix.de> <748a489687000b21d0e8f961fc2f9f963b0bc1d1.camel@siemens.com> <20260710115145.32729a7c@gandalf.local.home> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk X-Mailing-List: linux-rt-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Flowmailer-Platform: Siemens Feedback-ID: 519:519-68982:519-21489:flowmailer On Fri, 2026-07-10 at 11:51 -0400, Steven Rostedt wrote: > On Fri, 10 Jul 2026 09:23:16 +0200 > Florian Bezdeka wrote: >=20 > > uname might qualify, yes, but keep in mind that this sysfs based API is > > already used, so a removal might break applications. Yes, userspace can > > be fixed / adjusted, but it remains bad style, no? >=20 > Then at most it will likely just stay in the -rt patch set. As it was nev= er > mainlined, it's not breaking any user space that uses only the mainline > kernel. >=20 Depends on what you consider a valid update scenario. Updating from 6.1- rt with sysfs available to something like 6.18 (no sysfs anymore) will still break - as long as you do not (force) update userspace in lockstep. I learned meanwhile that our detection moved to uname meanwhile, so this is not a problem for us anymore. Florian