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 3BCF23C1F for ; Sat, 9 May 2026 13:17:19 +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=1778332639; cv=none; b=XYUI9Pllh2Y7LYaRPPNwDPLBIRLK9pQWnJ/D293PYnjr0oAFusAQDZ5msLlQk6OK8JzvtSQukV0SkV0ngGKPNf0X2l06S65PU9zl4sH8+kffkmjKmMyisEG4OJerwPa5DITx6vN+tynjynttUaypbA28xr0MEbyi9C2MVcLAQ6w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778332639; c=relaxed/simple; bh=GovmqvW+H8iHnBrgX5Bhn8ssZFtFngl8cW/75itPgxc=; h=Message-ID:Date:MIME-Version:Cc:Subject:To:References:From: In-Reply-To:Content-Type; b=IqzvH1WWRFzTDWTpYOegUeyvDdrfV+d91B/ZEdqLKSMGQcV05J1PtolGb+wrrq5AY4w7cH7df9AmBlpsOFBd8MezIdPTDfU3fgV1eMh0CIxAdRNTGj3xdtQ8KjTFLcisak/koczRaZhFTBkmO0jXhMa9hptguvIkrioLpO+rGP4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JM2jyvsj; 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="JM2jyvsj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E09BCC2BCB2; Sat, 9 May 2026 13:17:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778332638; bh=GovmqvW+H8iHnBrgX5Bhn8ssZFtFngl8cW/75itPgxc=; h=Date:Cc:Subject:To:References:From:In-Reply-To:From; b=JM2jyvsjgrW/sEbfot3VXAFO/w/ZmXzf/UlQRSCyR5t8tFkZr9u9UOWx1DhYy6tC+ oP/YbApXTMkPBScJ3BieIvjZuh1Xi8VR5mym1D9UO2Tcx2EHpOoreMsx9kZC0uFcIG 7GPnkdru5mtNvYVHl7gqtPsaGr4wXUiAe1pLRD+ONFh68NqAnQFamOLvnfdswq9CQW Bjoon6RGUQZK7q22Tj9lPhgw7Gq35Xie+16K5S0dkx8V58Ft/tZrcS5FGbkiFAzPCw pbu3H/dg4jDjeeC/Uepf6bxYWCpvp255F5q4n2cJ+mIyoMYi0J+cyBYBOWARBrtY18 27/AB+9nyc42g== Message-ID: <04ab5f17-2f63-49e4-8d4b-af781f5ff704@kernel.org> Date: Sat, 9 May 2026 21:17:14 +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, linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, baijiaju1990@gmail.com Subject: Re: [PATCH] f2fs: annotate lockless NAT counter reads To: Cen Zhang , jaegeuk@kernel.org References: <20260505125510.1369132-1-zzzccc427@gmail.com> Content-Language: en-US From: Chao Yu In-Reply-To: <20260505125510.1369132-1-zzzccc427@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 5/5/26 20:55, Cen Zhang wrote: > nat_cnt[] is updated while callers hold nat_tree_lock, but F2FS samples > the counters locklessly in f2fs_available_free_memory(), > excess_dirty_nats(), and excess_cached_nats(). Those helpers only steer > cache reclaim and background sync heuristics; they do not control NAT > entry lifetime or checkpoint correctness. > > Document the intent with data_race(READ_ONCE()) and a short comment > instead of adding locking to the balance path. > > Signed-off-by: Cen Zhang Reviewed-by: Chao Yu Thanks,