From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 0FF5447F4D for ; Wed, 4 Sep 2024 21:18:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725484700; cv=none; b=qqPpXNI4YgzkZVMreU4WBn5ICgg3RH1U/+xoFxwScHXdBU/oKQIXBW0jMG7xFD03zoSb2cTv7BUhlsAt4QQr23xIb8idMR9YVhj62UfKAnW1fvQ8jqmkJmcLmYgBL4RV+wvT7woSYLtIcDSD8LstD/Ti++dVkGcKko1eeTSgzYA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725484700; c=relaxed/simple; bh=WdVavWvCcaDT0xnVmcrUlqUm2Tx6+1qyqvxjnIpjqhQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ODUf5mfG7D3AvTKaUba/RQJ/3RKFKks+b7hIcp+0tXgqJ4jolbygAkkhQKqdIWjflLwxOotIiTNzLL/CK3c21cafcdz9O1CVr92XVFgIsOQimUnrmO/G78Cke38DiD6g1U74v6hfWkdy6dRp+bgPMOPepJ3V3cw092uUHhRhDUk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DXREPvFg; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="DXREPvFg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 41A3EC4CEC2; Wed, 4 Sep 2024 21:18:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1725484699; bh=WdVavWvCcaDT0xnVmcrUlqUm2Tx6+1qyqvxjnIpjqhQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=DXREPvFg0K7ztkLPwubRj9O2cwzthjQ5G49/NUvL7AH1rP86/Q8Zlgb9R2uwCFlLw /POmeR9uC20rLy0LHdA3Z7ba8ndTfBpUoSscSHsBo3GXX/3l5kddIqFSZgK4j2QGvh 0hDWEUpkL20XTRt3pdhj4KbumvUM5KE3QGph+JMjrhDNipLgGYbBCzM25Yca30srCB yMrncTAqQtyyD6YAX3FUcDVs7DzV7OVrF5BbTGx9i6F5ffh7K1zLMs4iqA90Nxl78I Jh0oBsGDbtUQUIsZNJPtAFVF1CvPkSqEOzJAgB9JjdzV/kikUiWrG0rzxbdZycoXMM JvjDpTNPKfoFA== Date: Wed, 4 Sep 2024 23:18:16 +0200 From: Frederic Weisbecker To: Waiman Long Cc: Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , linux-kernel@vger.kernel.org, Phil Auld Subject: Re: [PATCH v3 2/2] sched/isolation: Consolidate housekeeping cpumasks that are always identical Message-ID: References: <20240904183650.1053708-1-longman@redhat.com> <20240904183650.1053708-3-longman@redhat.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=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20240904183650.1053708-3-longman@redhat.com> Le Wed, Sep 04, 2024 at 02:36:50PM -0400, Waiman Long a écrit : > The housekeeping cpumasks are only set by two boot commandline > parameters: "nohz_full" and "isolcpus". When there is more than one of > "nohz_full" or "isolcpus", the extra ones must have the same CPU list > or the setup will fail partially. > > The HK_TYPE_TICK, HK_TYPE_DOMAIN and HK_TYPE_MANAGED_IRQ types are > settable by "isolcpus" and they can be set individually. The other > housekeeping types are all set by "nohz_full" without a way to set them > individually. So they all have identical cpumasks. And HK_TYPE_TICK is part of them, so it should become HK_TYPE_KERNEL_NOISE. > > There is actually no point in having different cpumasks for these > "nohz_full" only housekeeping types. Consolidate these types to use the > same cpumask by aliasing them to the same value. If there is a need to > set any of them independently in the future, we can break them out to > their own cpumasks again. > > With this change, the number of cpumasks in the housekeeping structure > drops from 9 to 4. There is no other functional change. > > Signed-off-by: Waiman Long > --- > include/linux/sched/isolation.h | 18 ++++++++++++------ > kernel/sched/isolation.c | 9 ++------- > 2 files changed, 14 insertions(+), 13 deletions(-) > > diff --git a/include/linux/sched/isolation.h b/include/linux/sched/isolation.h > index 499d5e480882..e2c42172de82 100644 > --- a/include/linux/sched/isolation.h > +++ b/include/linux/sched/isolation.h > @@ -7,15 +7,21 @@ > #include > > enum hk_type { > - HK_TYPE_TIMER, > - HK_TYPE_RCU, > - HK_TYPE_MISC, > HK_TYPE_TICK, > HK_TYPE_DOMAIN, > - HK_TYPE_WQ, > HK_TYPE_MANAGED_IRQ, > - HK_TYPE_KTHREAD, > - HK_TYPE_MAX > + HK_TYPE_KERNEL_NOISE, > + HK_TYPE_MAX, > + > + /* > + * The following housekeeping types are only set by the nohz_full > + * boot commandline option. So they can share the same value. > + */ > + HK_TYPE_TIMER = HK_TYPE_KERNEL_NOISE, > + HK_TYPE_RCU = HK_TYPE_KERNEL_NOISE, > + HK_TYPE_MISC = HK_TYPE_KERNEL_NOISE, > + HK_TYPE_WQ = HK_TYPE_KERNEL_NOISE, > + HK_TYPE_KTHREAD = HK_TYPE_KERNEL_NOISE Why not removing them entirely and only keep HK_TYPE_KERNEL_NOISE ? Thanks. > }; > > #ifdef CONFIG_CPU_ISOLATION > diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c > index 5345e11f3d44..61d0f97341c3 100644 > --- a/kernel/sched/isolation.c > +++ b/kernel/sched/isolation.c > @@ -9,14 +9,10 @@ > */ > > enum hk_flags { > - HK_FLAG_TIMER = BIT(HK_TYPE_TIMER), > - HK_FLAG_RCU = BIT(HK_TYPE_RCU), > - HK_FLAG_MISC = BIT(HK_TYPE_MISC), > HK_FLAG_TICK = BIT(HK_TYPE_TICK), > HK_FLAG_DOMAIN = BIT(HK_TYPE_DOMAIN), > - HK_FLAG_WQ = BIT(HK_TYPE_WQ), > HK_FLAG_MANAGED_IRQ = BIT(HK_TYPE_MANAGED_IRQ), > - HK_FLAG_KTHREAD = BIT(HK_TYPE_KTHREAD), > + HK_FLAG_KERNEL_NOISE = BIT(HK_TYPE_KERNEL_NOISE), > }; > > DEFINE_STATIC_KEY_FALSE(housekeeping_overridden); > @@ -194,8 +190,7 @@ static int __init housekeeping_nohz_full_setup(char *str) > { > unsigned long flags; > > - flags = HK_FLAG_TICK | HK_FLAG_WQ | HK_FLAG_TIMER | HK_FLAG_RCU | > - HK_FLAG_MISC | HK_FLAG_KTHREAD; > + flags = HK_FLAG_TICK | HK_FLAG_KERNEL_NOISE; > > return housekeeping_setup(str, flags); > } > -- > 2.43.5 >