From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sipsolutions.net (s3.sipsolutions.net [168.119.38.16]) (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 6F16222B8C6; Fri, 9 May 2025 10:03:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=168.119.38.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746785004; cv=none; b=nfRmOgsUrTYyAusF0UzuMIMpwaAID3J+cQR2+BayNjbZ1lh8kwbzZ17Wc197W8zoKAW1dthAbcaPBzlJHeb18Y7iEcZ/QYxcNpt0FgT5hsH+Lga5INf5MW45qUkPQdLeEz8Z7XQhGpVVR5LPdn5p21XQphJmd0vIyzMnZzHMlVE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746785004; c=relaxed/simple; bh=o3762g+GuSJsrko3ED8b4sId/L19pQq5bBo6syEWPvg=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=jp+B0QjslmM3zV+TvjZdn1xOak2XjXGsUPHfDFCGA+kCu20mUsLnPMw1XkwPqIGm53xARvsbyfAtktWmcyflvyOTKskSWqP4fzKWUZoxxhWwLrhma2mD6n7bcpTpaGPFcX7y/lRBPFzSe+UZ6m3LshTpDZ1IFxfeoWfRv8/f0S8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sipsolutions.net; spf=pass smtp.mailfrom=sipsolutions.net; dkim=pass (2048-bit key) header.d=sipsolutions.net header.i=@sipsolutions.net header.b=jD68dace; arc=none smtp.client-ip=168.119.38.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sipsolutions.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sipsolutions.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sipsolutions.net header.i=@sipsolutions.net header.b="jD68dace" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sipsolutions.net; s=mail; h=MIME-Version:Content-Transfer-Encoding: Content-Type:References:In-Reply-To:Date:Cc:To:From:Subject:Message-ID:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-To: Resent-Cc:Resent-Message-ID; bh=k54YIIAt1HX3qxqsLaJ9Pdr+Jyv+TK7yUdd/QX5Nw1g=; t=1746785002; x=1747994602; b=jD68daceGGLvl/qj3rb4kIRjACpuj9aboDtIgiln/gm9WO/ quwiO8EvyNBSGB/Xv9y9766BYlXJQD62vhiop/Rs24++4j2UAva0zshIws/l+hQwR2rGoExbHO/3N 4OJeWM4G2HYI+P6AmRe+CQjlnWEo0IuOzvIIr0AXKCnAc228k3NMg0FDsyPntCJ0DK/YddQvChj2u 6n6TGOJbCQ7zIh7i/oEDJ2tCH95ANSYYaUSl6f5vDE0Y4GJSgPCiRMzWz7yAxkEOfwg9PPLdQ0uZv C98mYo+YaOMensBCkLK3XBKdhyvphtdsNLWkKpdLx5a/e61zoeZvH8qgiour/LdQ==; Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.98.1) (envelope-from ) id 1uDKZQ-0000000DFW4-1AvP; Fri, 09 May 2025 12:03:08 +0200 Message-ID: <05954e6dde3369a0ecf26f5225643afa15850f60.camel@sipsolutions.net> Subject: Re: [PATCH 6.12] Revert "um: work around sched_yield not yielding in time-travel mode" From: Johannes Berg To: Christian Lamparter , linux-kernel@vger.kernel.org, linux-um@lists.infradead.org Cc: benjamin.berg@intel.com, sashal@kernel.org, richard@nod.at, stable@vger.kernel.org Date: Fri, 09 May 2025 12:03:07 +0200 In-Reply-To: <20250509095040.33355-1-chunkeey@gmail.com> References: <20250509095040.33355-1-chunkeey@gmail.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.54.3 (3.54.3-1.fc41) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-malware-bazaar: not-scanned On Fri, 2025-05-09 at 11:50 +0200, Christian Lamparter wrote: >=20 > What's interessting/very strange strange about this time-travel stuff: > > commit 0b8b2668f998 ("um: insert scheduler ticks when userspace does no= t yield") >=20 > $ git describe 0b8b2668f998 > =3D> v6.12-rc2-43-g0b8b2668f998 > (from what I know this is 43 patches on top of v6.12-rc2 as per the man p= age: > "The command finds the most recent tag that is reachable from a commit. [= ...] > it suffixes the tag name with the number of additional commits on top of = the tagged > object and the abbreviated object name of the most recent commit." >=20 > But it was merged as part of: uml-for-linus-6.13-rc1 : > https://lore.kernel.org/lkml/1155823186.11802667.1732921581257.JavaMail.z= imbra@nod.at/ That's not all that implausible - UML maintenance is slow and we all have a lot of things to do... so chances are we just didn't send a pull request for 6.12-rc even though the tree was already there. I'm trying to improve that but it's not really a focus for any of us. johannes