From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 3F79A3AA1B8; Sun, 12 Jul 2026 20:26:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783888016; cv=none; b=YT8/e91Z0WwTzUz3PevLAq88Vebvig7/fsiR4tOvIHhUOIVjmiRKz/rIuS+s/Lq07RqBAx2OfC6PQTilw3CWAqHwpzRUOHgBOiMfKs3ygUXXhb1WAzeOq7MMz0lQwELFoCFpjPC30tJ2mzSObQS3Hn49NGLraI6bTrm8VF+wZ04= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783888016; c=relaxed/simple; bh=eCf1408MFwUzNB2SfuMvSTZh13dv9dkzqobURrkEYAI=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References; b=c892k2ORuH1/bs8CaVBHun36dTuoYdbt5pgYd63JgjLhivvNvlGmfhWvL9q04sLCUXDRqrWOYJFbXXg6mGCpFvkmSCfA+wV1m8mGFFgKjDA/K7wTPBLXQePkgxnezersOxKmtJGwfS1G4wEGLxcAfRroIjFBcOMkkWNu7Ed7ssY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=U2n+77Fc; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="U2n+77Fc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A0DA61F000E9; Sun, 12 Jul 2026 20:26:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783888014; bh=eCf1408MFwUzNB2SfuMvSTZh13dv9dkzqobURrkEYAI=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=U2n+77Fc9fwhTD8H+MNxdJB8y6OeyW+zoGqZ1+ZU0uVCoXLUsGDyvVOWl72NGlqpK 6IsPOEjEqad87TdSfvxOaiM5d3+NeteplkTwrmrhgkMIOhzDyLe2cjXS9GU2czvSoI T/ZJyJ9ihclIMzfJ+hE8Hg5GYVdnJlAWiECLDWkrwKR4OSaXKeo8d4cNEXHoQvs4+t F8xa2iadSHEA0NG6391fkwdKclX03z2Vfydb3p2Sgd8v3NHSTgXmTXKDuOa+con6Ih hQXYkI2Q87xPl7cvydOxoH8bwilRSsnIQH4cRbB/NHKeGYmTCIC7wPF7sNaxrhbgXq e6SXKVdOFRfYQ== Date: Sun, 12 Jul 2026 10:26:53 -1000 Message-ID: <60b5a9ee3c9d3f248cf70e68014b8cea@kernel.org> From: Tejun Heo To: sashiko-reviews@lists.linux.dev Cc: Johannes Weiner , Michal Koutny , tj@kernel.org, sched-ext@lists.linux.dev Subject: Re: [PATCH 1/2] sched/psi: Create the psimon kthread outside of cgroup_mutex In-Reply-To: <20260712180032.087AF1F000E9@smtp.kernel.org> References: <20260712174619.3553231-1-tj@kernel.org> <20260712174619.3553231-2-tj@kernel.org> <20260712180032.087AF1F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: sched-ext@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Hello. > If this error path is reached (e.g. by racing pressure_write() with cgroup > rmdir making of->priv NULL), the calling thread would sleep for an RCU grace > period while holding cgroup_mutex, stalling all other cgroup operations. > > Could the trigger destruction be deferred until after cgroup_mutex is dropped, > or handled asynchronously to avoid stalling the cgroup subsystem? This is pre-existing - rmdir and cgroup.pressure disable already destroy triggers under cgroup_mutex when draining open fds. Maybe something to improve in the future. Thanks. -- tejun