From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mout-p-201.mailbox.org (mout-p-201.mailbox.org [80.241.56.171]) (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 9065D38BF61 for ; Fri, 22 May 2026 21:31:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=80.241.56.171 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779485499; cv=none; b=uahovu1U/Xgd7OR+pM87nV8wGeyZCIifg7u+t0vYUvYyKKoRpMOihZKz1Pf9UP7Fq2Y3UgEgBuKxVvV70cwThcMeOgvtQDmxpPbJh2arvJ8shjFSs85t0bsTIaDdHXDhSztft1UBD/WOEuxDdLzBvG7N/l5QEEWNy+UM3E7sgsg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779485499; c=relaxed/simple; bh=j1xddUMMBFb16SlgtUX0HJ3qWkaM0wyMdYabFeuRnqQ=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=B7MSPQU1dgz3yHuIXJWnEKfdQ2F+VAmhXi5dVQ+geHSTyRFTvhspe+Cpr8/AqpQAiOZxbSLXbLoZ5UNJvqtwnYTTyeb2y2x7gSsimaWtbjOccDw3QpjMcnEej+7jQ4NEdnQyanWKlD0UuOK5+cDM9VK8CvJPHHyInN6EckMUwcQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=mailbox.org; spf=pass smtp.mailfrom=mailbox.org; dkim=pass (2048-bit key) header.d=mailbox.org header.i=@mailbox.org header.b=V2njL/sY; arc=none smtp.client-ip=80.241.56.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=mailbox.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mailbox.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=mailbox.org header.i=@mailbox.org header.b="V2njL/sY" Received: from smtp2.mailbox.org (smtp2.mailbox.org [10.196.197.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-201.mailbox.org (Postfix) with ESMTPS id 4gMdkp1Rr7z9v7g; Fri, 22 May 2026 23:31:30 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mailbox.org; s=mail20150812; t=1779485490; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=UXbfCdtu7pGqLsOvdQmNScTjV6C5Xgofhl0P02rcJTY=; b=V2njL/sYNgXsEjgp6TbytVFj7NzfjJ7dLbRTCdvJS69TPWx6P5sQslBFWOm2FqKglmEupb xwrfTJJDz2P7FrrMDM+cWjNWZC5yVAVBu6Fpvn7prNk/9pLb9hlzKTkhBALZwcPcFZEBR/ Cs62WmZNC2E8LjPgbrasRFC0tWnh78yzaWVlXDbaMWbdRauUQ9MqI8dJfftpwNHt+Y9Z0h JhhUIDXaq7Z+Pt1/fknkxOEKDmKaSw8pnISl1Xbyx2Ns3+D+Xj1ChzCwS5cVCXzbOralF8 NenNLQzhoUpH3P29COX1DLIFGmWQgwnJgOiXHHzhPwOhOP9ZpHJ/ENbQ1YT78Q== From: Lukas Beckmann To: Sasha Levin Cc: stable@vger.kernel.org, regressions@lists.linux.dev, Mike Galbraith , Peter Zijlstra , Juri Lelli Subject: [PATCH 6.12.y 0/3] backport missing dependencies of d66792919d4f Date: Fri, 22 May 2026 23:31:17 +0200 Message-ID: <20260522213120.1205100-1-lbckmnn@mailbox.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-MBO-RS-ID: 4e49c896b262d06495c X-MBO-RS-META: rdttdt3rxadx8eh3tpqjxs9zfj138bm7 Commit d66792919d4f ("sched/deadline: Use revised wakeup rule for dl_server") in the 6.12.y stable tree (upstream commit 14a857056466) depends on three upstream commits that were not backported: commit cccb45d7c429 ("sched/deadline: Less agressive dl_server handling") commit 4ae8d9aa9f9d ("sched/deadline: Fix dl_server getting stuck") commit a3a70caf7906 ("sched/deadline: Fix dl_server behaviour") Without these, cyclictest under load reports latencies up to ~50ms on PREEMPT_RT. For context, see the regression report: https://lore.kernel.org/regressions/04657838-46d1-432d-95e1-eb73b930b032@mailbox.org Testing: Tested on two different machines with Debian's PREEMPT_RT config for about 10 hours. Without these patches cyclictest under load spikes to ~50ms in less than 30 minutes, with the series applied the latency spikes are gone. Thanks, Lukas Peter Zijlstra (3): sched/deadline: Less agressive dl_server handling sched/deadline: Fix dl_server getting stuck sched/deadline: Fix dl_server behaviour include/linux/sched.h | 1 - kernel/sched/deadline.c | 16 +++------------- kernel/sched/fair.c | 16 +--------------- kernel/sched/sched.h | 37 +++++++++++++++++++++++++++++++------ 4 files changed, 35 insertions(+), 35 deletions(-) -- 2.54.0