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 C4E134483A5 for ; Wed, 2 Sep 2026 12:22:18 +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=1788351739; cv=none; b=RmlXnNlkD3lgS6m9pBmPsFAMCGWhZ/XxehOnFuJ79/YgSORJnq4wEJdj+XRjY9/aU2i6/njpzZKsGgMzss7qeInfuoTMfnTyq/u5mbjXiLFCGjnb3nhX9hDFce9G+hDyqJoCcQO6dXpi7NRp4Dz/XjcGvBF0ENejfttvIdibFm0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788351739; c=relaxed/simple; bh=rXgg491TClmqHMl6PPwcPkJvOA7J88dCd8/gyHlyn/g=; h=Message-ID:Date:MIME-Version:Cc:Subject:To:References:From: In-Reply-To:Content-Type; b=u97IIeVN9x5krM98Fyi6x2/SHEQQbv5uGO8WiVB2OkYQw8qKY3mU/goz7vnAUtisVehM8OOs8bH0Y4doSaffkWYhiVkZ4mdvLNajzuqAq+PmyWnVAD8XDK5hJlyiCLnINQVhpMN481sqLVRPwWZwOxaGzRFXcYkGKVGP1oNw/qw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LxRvGO/M; 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="LxRvGO/M" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 687421F00A3E; Wed, 2 Sep 2026 12:22:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788351738; bh=89TMwyN9hNCf8InjZ/BoJd7/XuvClRBjnluIOo0LKe0=; h=Date:Cc:Subject:To:References:From:In-Reply-To; b=LxRvGO/MggPRXmQmjjeoCO+sMdBslb0FTEP1B0/rRrp4etc/feY4cPSZonVNFcYXc hrS1Mc6wG3Tk5z7H/LQmZwE8l5pnufIrGBkj8SAggB6sYy9Nsvoa6fUr1oGDWySHMn L2kiYwx+XnONiqIXzQzN9l7KPJjUC53lYjlTlxFNLT0Xc4+kt3lWcIBlqjDXXLbJnx Q7BUvE216Kx1jXJvkd3katwP+Cq7X+bTxPRNt2IIGOE9kY96DDmhoPWJcK0LM9XYLX lzKVXBBYwqahc5Z3Z0jtS/HY/CbwVetvwOYxM/JyBx07wxCAsFFY9n3T9HSGX/HzuI cVmcYwM9muuJg== Message-ID: <46ee7fba-6a20-473c-b87d-856fa4ce1865@kernel.org> Date: Wed, 2 Sep 2026 20:22:15 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Cc: chao@kernel.org, Jaegeuk Kim , qiwenjie@xiaomi.com, linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Subject: Re: [PATCH v5 04/12] f2fs: cache: introduce writeback thread To: Wenjie Qi References: <20260831092227.739737-1-chao@kernel.org> <20260831092227.739737-5-chao@kernel.org> <20260902115636.691796-1-qiwenjie@xiaomi.com> Content-Language: en-US From: Chao Yu In-Reply-To: <20260902115636.691796-1-qiwenjie@xiaomi.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Wenjie, Thanks for the review, I've fixed all issues in 04/12 and 09/12 patch in https://git.kernel.org/pub/scm/linux/kernel/git/chao/linux.git/log/?h=feature/cache, please take a look. On 9/2/26 19:56, Wenjie Qi wrote: > Hi Chao, > >> static int f2fs_cache_writeback_kthread(void *data) >> { >> unsigned int interval = cache_thread->cache_wb_interval; >> } > > and startup initializes the field after `kthread_run()`: > >> task = kthread_run(f2fs_cache_writeback_kthread, sbi, "%s", name); >> if (IS_ERR(task)) >> return PTR_ERR(task); >> >> cache_thread->cache_wb_task = task; >> cache_thread->cache_wb_interval = DEF_DIRTY_CACHE_TIMEOUT; > > `kthread_run()` wakes the new thread before returning, while > `cache_wb_interval` is initially zero. The worker copies the field only > once, and the sysfs store later updates the field rather than the local > `interval`. > > Can the worker observe zero at startup, and can a later > `cache_wb_interval` write change the interval used by that worker?