From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 854272E0902; Mon, 13 Oct 2025 06:26:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760336789; cv=none; b=rdxJyvhZJ8QkCApr9asqaPBOMpIgyTz5uZrK6aZ915dtqnQEBSEQm+07vilC5oSij5BUify6vXg5HESRqvpIPI6SnixcRE+UL9cwoIN9TnGLcOaDjryykDYRUj2J4lIgTTcjMzy+PqCN5YRwzUqfGD1aiJR54qPcVcD3wZXROqI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760336789; c=relaxed/simple; bh=vbKncTUnW0SDgxIMV/xZOHOGhSy4m/PbQfk2ZEL7F34=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Y56F6iFDTuTDqNEy2of7O52MMuGb7Lvn3SrFi7laB+49vg1eiEao5oBbUOspbkfFtEjjIG8kwhXEv46CFM7aEieOWYqnr86ky/5W1gbLCO744Et5wR3fYTpbhHgvdlh2yaiOB8yJFf8WRH8Dwek67yETvg+dVOFvaAVOMVQ2GTU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=i9gLTuyT; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="i9gLTuyT" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=kIugL04z9TJ0M/06doyNc0me9LOxYYhXKGY7hU7qIYs=; b=i9gLTuyTpsPUOnpl7T1yAsaW6n apUI7yby3tuZZLYxHc5Vzgon9ZxSdrRB3N1XrDjdXLW7FsfksXepGLIjppFDMzW9PXBemX9rDVFnu cq8+uaMukIUxQcjHTBWzAjE8MlzPVSUJnYYISZbUo8A8Nld0RYl3gJ9/h4gDpvDhVA2KH1/5mvCd5 BqeY0lULi2AN32ybEl13VTyfwAgw1wxOZdzer7SSr75URabqpa6NsQyobqi/m80y3g7hv2hZSgBPo btWHV0mz6wf4QMD3NIUL9z96dkO8094QlUMAJm8u6U34E/ZooV2iDms4HgZzGPC18kUNVSjC2Otg7 TjIIV5DQ==; Received: from hch by bombadil.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1v8C0m-0000000CNjo-2bVN; Mon, 13 Oct 2025 06:26:24 +0000 Date: Sun, 12 Oct 2025 23:26:24 -0700 From: Christoph Hellwig To: Ming Lei Cc: Christoph Hellwig , Jens Axboe , linux-block@vger.kernel.org, Mikulas Patocka , Zhaoyang Huang , Dave Chinner , linux-fsdevel@vger.kernel.org, io-uring@vger.kernel.org Subject: Re: [PATCH V4 6/6] loop: add hint for handling aio via IOCB_NOWAIT Message-ID: References: <20250928132927.3672537-1-ming.lei@redhat.com> <20250928132927.3672537-7-ming.lei@redhat.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Thu, Oct 09, 2025 at 09:25:47AM +0800, Ming Lei wrote: > Firstly this FS flag isn't available, if it is added, we may take it into > account, and it is just one check, which shouldn't be blocker for this > loop perf improvement. > > Secondly it isn't enough to replace nowait decision from user side, one > case is overwrite, which is a nice usecase for nowait. Yes. But right now you are hardcoding heuristics which is overall a very minor user of RWF_NOWAIT instead of sorting this out properly.