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 F1E61645; Wed, 6 Nov 2024 22:53:06 +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=1730933587; cv=none; b=qrVeIaCi/WURy8CegVnUIsQl0IZarNRRB/vZhxEzmJDhE7AjsirXWpEPK4UauAvePR3FUZmtxIJY3TKhY/rfupMVttonzidlifmGt10hlYa50pHKV1lNm5VZI+dKzFIOGAOqVARDGTspMNThKy9LtPvHgaRpyOuqbxaEAOh8C7I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730933587; c=relaxed/simple; bh=2rG0V8XGr+zNT9gx3HFi1etRMN45S04G2ksfE2rB3jY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=knfEa5Ke0crmOtgdKrtX55WaiAIjb9YkP1Fr7QpUop0Jyji4seIAV9LfTVAi7+iLu6G2SJMovxeFvkYSevPUXgDMGE75jPHu9HuN3Tt9BjBxIzy2XPk1BLiQiBRJsyHhPIsXSdLWo61sGLbZlKvR8huJDb9p8yp3pa0V+ojprTw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LOLifT3Y; 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="LOLifT3Y" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5FF89C4CED0; Wed, 6 Nov 2024 22:53:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1730933586; bh=2rG0V8XGr+zNT9gx3HFi1etRMN45S04G2ksfE2rB3jY=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=LOLifT3YKXRXzrX5ofcXb0Y3OpIX1R369xEpkdqk068QHjZGE3jTRIH4INnAzVMHU SoMtuAd9i8OPF9I7+Okhs0NbO9nO3I0OLR7glx4gkbEBPoHU1dPF9sidB8GDYCV/tx WiRfkU0udw3IKG4qtZTZhYpaZVdsQ57CwcdXM950l15sdbdOVb+JKgMg3XMfmcLtCc u7UQ4g2tEwQ3RqQkN4C3oeaGx44d8ot4BKjiV+CRtSalivZgZlFpZLgqM4Be2kNo+d QtbdMcEqbOlTydvGGZ2VCmTZ8n2QR37JpQwRR+vamw9q5naVV8ATKLg/Pea9ls65Qu ZdL3RoTj7w9ZA== Message-ID: Date: Thu, 7 Nov 2024 07:53:04 +0900 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: block/blk-zoned.c:579:5-24: WARNING: atomic_dec_and_test variation before object free at line 583. To: Jens Axboe , Christoph Hellwig Cc: kernel test robot , oe-kbuild-all@lists.linux.dev, linux-kernel@vger.kernel.org, Hannes Reinecke , "Martin K. Petersen" , Bart Van Assche References: <202411050650.ilIZa8S7-lkp@intel.com> <20241105153422.GA7132@lst.de> <20241105153733.GA7219@lst.de> <5b55417d-6b27-4186-bcfa-d6952624e99f@kernel.dk> From: Damien Le Moal Content-Language: en-US Organization: Western Digital Research In-Reply-To: <5b55417d-6b27-4186-bcfa-d6952624e99f@kernel.dk> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 11/6/24 00:56, Jens Axboe wrote: > On 11/5/24 8:37 AM, Christoph Hellwig wrote: >> On Tue, Nov 05, 2024 at 08:36:33AM -0700, Jens Axboe wrote: >>> On 11/5/24 8:34 AM, Christoph Hellwig wrote: >>>> On Tue, Nov 05, 2024 at 06:52:25AM +0800, kernel test robot wrote: >>>>>>> block/blk-zoned.c:579:5-24: WARNING: atomic_dec_and_test variation before object free at line 583. >>>> >>>> Does anyone know what this warning is supposed to mean? >>> >>> It's supposed to mean "use refcount_t for things like this". >> >> Have we finally resolved the performance problems with refcount_t for >> fast path operations? > > I mean it's closer, but it's still slower. Will always be so. Does it > matter for zoned devices? Probably not. > > I don't think it matters for this case. It's not like the ref itself is > something that is user controllable in terms of being able to get > anywhere near an overflow. OK. Will work on a patch to switch to refcount. -- Damien Le Moal Western Digital Research