From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-lf1-f48.google.com (mail-lf1-f48.google.com [209.85.167.48]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 290C41F16B for ; Sun, 17 May 2026 12:47:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.48 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779022080; cv=none; b=SzC3Vz0ssZT3N/Tfox6DSgYCcwgYS6mxm6zOpGFO3Ku6uLpOcQKg0ujYq9nI4xQvtlysA88bpFCyjS8kyUZlXv6isBB0zTI5D5YnXp3j7OmZ3G+gS6trxON0N1O/8tQM4NPc6ZCSh7xC22wgawhmqeZd6cgbu8ecKnYUtCVcr3I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779022080; c=relaxed/simple; bh=w+kfh1Dy6u+UktO/Ojj08U2MzX1bLrF0iJTEvIbhID4=; h=From:Date:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=QdGcAbMmDvrhyj2y6J5dKh0lazoDE7KqUI+shL+rmpD2gYWLBF+zcT5yw0btpEkZFdGS2EMCYqIShJeiAAOSe4Is9NRU9zdyGTyrLD4JwlgKY81icLGL/uM4TzpEjVkS8Kd/10thpBiRj1oZli9ceeiyN9W7q8kBUhWEAlxzUcw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=Kr6roRvx; arc=none smtp.client-ip=209.85.167.48 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Kr6roRvx" Received: by mail-lf1-f48.google.com with SMTP id 2adb3069b0e04-5a8d1f43432so2337112e87.3 for ; Sun, 17 May 2026 05:47:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1779022077; x=1779626877; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:date:from:from:to:cc:subject:date:message-id:reply-to; bh=ICmnR9jgJrAJ4e5TLBFpaZ6Ac4G7v2Tf75marMuEa4I=; b=Kr6roRvxoyRy9RDyMYvRJ5hI0/XtAQNkLb9onMuvv122Q3qVtJcgXDKY9/ooRkfmNm ZxHUY3iGRg+RAiN1I62cZHzoWyxh15+PiKk1OpBnPH+0f7DTYGEg5dvWWBjICW+0zkA+ 2qyHabMivMBxI5QRINBc3ds7qEplXSYtIjYicmYDkeBNSBKk0lb1QqRfTFCj8z9rA2W+ 8umV2vu6PMYXftup8JMFktVDUBzEZdWwRZewLiyNb85WZ/FgtEmmg6dxK0U8WoPCUCvG qSD6ChLxNsplgT7wtAspiPfomxmMxkqrWr9MAUzwOPtsn5LQGshCofw3Aa+yRA8VdiVy DPog== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1779022077; x=1779626877; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:date:from:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=ICmnR9jgJrAJ4e5TLBFpaZ6Ac4G7v2Tf75marMuEa4I=; b=Ahx6mm9OyUFmStIirN9xJht96PVwDqxdKvqSt+pU27/hs3J03LBx9hcZ5JRK/xIT5z Qrqvt1sPpIZ/NniezmmFIp4pLvCWiBf1VpJlinVDY8DkDs3dLM9e1i0xTOMl9QxO88NC z3SILaztDTnw/T41wvtVnDtZZqC2dD+ii2c79pqRCupJWEhLCSQWWggdiMq7qCqyw54F R6arvMw6PNlj/aGisvbDYAWCWpD4dPw6jx1UeXhLmE1PbgbissW4jqUj52Tdr3KdiX1X uwC0sJRpO6nwhQ7gtqh1s8LjoFyQXFyTNqq/tPH8Z9mWO4lkiO8BvV2gbj9SLkHRPIl6 hYFA== X-Forwarded-Encrypted: i=1; AFNElJ/SCRAezt8Snd1320NHitlViiWIXSSoSwOv6JnFyT0DA7B0JkLbxM1alMLPk3oG1Kjot53ACGtNCnNpof8=@vger.kernel.org X-Gm-Message-State: AOJu0YznqSc8YmVW1n1P3GnHOJivdIt0AhT7jIPjfiAvqXweF/HcOTzv yGsH59XsAGVm7g/IBSRX4YRk7myEoYItv1hVT2VtEUOCX0GL5psjYsdg X-Gm-Gg: Acq92OFm+S0fmCpyn9NQgJjh1hn1/ZPNiho436T/1hq82B/8Cd+3Qb205CmFai+IwMw 1N/+RSWk4tiH/jDLv+SK4VuVINJDu81b0BJmvU6ScWG3GvVpeESD+JBLz94H6r/0zOFUWY4CVPn C/y8fCPok0vsTngN20gMP53jLOicXbAkiGU655oPJOLewXIEJEWm4FfI6WcVZ8go3SVi22WYmsq 5KdfJN7YwikOzt+zMT1mVvg6wdRXV9OLIHeUnR6EnfhPL3W/g0KKe+G6AH7rmif55l3RaDbxjVp X1Nav97a4On0M5LkOBqvAXHr1LtX0f8QJN/7XrYvXmXs1twPr0iI4V1vHd1g3wMgqsfYSPCuKae /DL0J9lvu7uzycELVRA46RO/4A0Npmbqoak1d+RT4/6em0AhazqaKXj6uFdWlwYnavY23gIBKR8 H+uUQ/wfVAOmdPZ8zuKHs= X-Received: by 2002:a05:6512:10c8:b0:5a8:d1ed:8d4a with SMTP id 2adb3069b0e04-5aa0e747254mr3434370e87.40.1779022077116; Sun, 17 May 2026 05:47:57 -0700 (PDT) Received: from pc636 ([2001:9b1:d5a0:a500:de96:9acf:5dca:ede4]) by smtp.gmail.com with ESMTPSA id 2adb3069b0e04-5a90f11a654sm2685723e87.30.2026.05.17.05.47.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 17 May 2026 05:47:56 -0700 (PDT) From: Uladzislau Rezki X-Google-Original-From: Uladzislau Rezki Date: Sun, 17 May 2026 14:47:55 +0200 To: Thorsten Leemhuis , "Paul E . McKenney" Cc: "Uladzislau Rezki (Sony)" , "Paul E . McKenney" , Boqun Feng , Joel Fernandes , RCU , LKML , Vasily Gorbik , Frederic Weisbecker , Samir , Shrikanth Hegde , Tejun Heo , Linux kernel regressions list Subject: Re: [PATCH -next v1 05/12] srcu: Don't queue workqueue handlers to never-online CPUs Message-ID: References: <20260511175448.153326-1-urezki@gmail.com> <20260511175448.153326-6-urezki@gmail.com> 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-Disposition: inline In-Reply-To: On Wed, May 13, 2026 at 12:38:01PM +0200, Thorsten Leemhuis wrote: > On 5/11/26 19:54, Uladzislau Rezki (Sony) wrote: > > From: "Paul E. McKenney" > > > > While an srcu_struct structure is in the midst of switching from CPU-0 > > to all-CPUs state, it can attempt to invoke callbacks for CPUs that > > have never been online. Worse yet, it can attempt in invoke callbacks > > for CPUs that never will be online, even including imaginary CPUs not in > > cpu_possible_mask. This can cause hangs on s390, > > Uladzislau, Paul, according to the fixes tag below this change fixes a > change that went into 7.0-rc6 -- and apparently causes a "hang" on some > architectures. So shouldn't this be heading to mainline instead of > -next? Ideally with a stable tag to ensure backporting to 7.0.y, but > that is a separate decision? > I assume it will be picked to stable since there is a "Fixes:" tag. From the other hand i can explicitly update commit message with Cc: stable@vger.kernel.org Paul, any thoughts? -- Uladzislau Rezki