From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id C836E12C7FA; Tue, 30 Apr 2024 16:47:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714495635; cv=none; b=BwkBQKt0ScFLb/1rpmaZOB1QN1w79eoZRyxfkUn0ueXnnbo0MtqP1xIfggG72Fav0j4z7SEOhZAlgioZpbesRILnDsvIDZc5W+QGp7rssSbpbhyTR9m5PruHYrQVLjoap8brxEfo1leD2UP1wWoawFQ409V8cbPnqhQJZLUUJ8M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714495635; c=relaxed/simple; bh=93evZwhOPpMP46YPBM7x7WZ4DoHMEWykJH9vC1Lzlfc=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=sstGUmSZ81/7MPOnyzeGHTGBAefrrD557dRmKTAtq6AeJ6fRZDpGTVh19CWvuuoKVhvR/BV4ereFjUKjd00e5rVn6aUPytdbg5hE9HDtR7aBz9U0x7S9a7C5deHDVnu4TIJunOMPEE7F5W5EQC5sMyt1zjg5FitU9tMeBvzWRRg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 85B872F4; Tue, 30 Apr 2024 09:47:39 -0700 (PDT) Received: from [10.57.65.13] (unknown [10.57.65.13]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 4431E3F762; Tue, 30 Apr 2024 09:47:12 -0700 (PDT) Message-ID: <73edaf80-9251-4c3b-8fcc-202dd617335a@arm.com> Date: Tue, 30 Apr 2024 17:47:10 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 2/2] thermal: core: Move passive polling management to the core To: "Rafael J. Wysocki" Cc: Daniel Lezcano , LKML , "Rafael J. Wysocki" , Linux PM References: <5790995.DvuYhMxLoT@kreacher> <2949052.e9J7NaK4W3@kreacher> Content-Language: en-US From: Lukasz Luba In-Reply-To: <2949052.e9J7NaK4W3@kreacher> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 4/30/24 16:52, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > Passive polling is enabled by setting the 'passive' field in > struct thermal_zone_device to a positive value so long as the > 'passive_delay_jiffies' field is greater than zero. It causes > the thermal core to actively check the thermal zone temperature > periodically which in theory should be done after crossing a > passive trip point on the way up in order to allow governors to > react more rapidly to temperature changes and adjust mitigation > more precisely. > > However, the 'passive' field in struct thermal_zone_device is currently > managed by governors which is quite problematic. First of all, only > two governors, Step-Wise and Power Allocator, update that field at > all, so the other governors do not benefit from passive polling, > although in principle they should. Moreover, if the zone governor is > changed from, say, Step-Wise to Fair-Share after 'passive' has been > incremented by the former, it is not going to be reset back to zero by > the latter even if the zone temperature falls down below all passive > trip points. > > For this reason, make handle_thermal_trip() increment 'passive' > to enable passive polling for the given thermal zone whenever a > passive trip point is crossed on the way up and decrement it > whenever a passive trip point is crossed on the way down. Also > remove the 'passive' field updates from governors and additionally > clear it in thermal_zone_device_init() to prevent passive polling > from being enabled after a system resume just beacuse it was enabled > before suspending the system. > > Signed-off-by: Rafael J. Wysocki > --- > > v1 -> v2: > * Add a WARN_ON() check for tz->passive < 0. > * Do not start passive polling until tz->passive is positive. > > --- > drivers/thermal/gov_power_allocator.c | 12 +++++++----- > drivers/thermal/gov_step_wise.c | 10 ---------- > drivers/thermal/thermal_core.c | 14 +++++++++++--- > 3 files changed, 18 insertions(+), 18 deletions(-) > Reviewed-by: Lukasz Luba