From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 C8B2329A31C for ; Mon, 6 Oct 2025 14:18:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759760311; cv=none; b=QGIFklEAwx0zvDK7RJtiPWPoJAdvAp60Fi9X0ZkMtm1/gK3kSooyMDn33vq7iYGV/1JPheHeG0Rcv65NMsW1wohq48baS8p62FO+A/cXjjwNwmD5tfArBcPmbTVuvfv0gpzwlkkkNnSVxxj7TL3M6gJaYQ1ewG48/pKUU2uPZE4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759760311; c=relaxed/simple; bh=lD+gJOH7BbrAfztkPzkBUkg4YmpmpiNcVfG5FaH5V0s=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=PKAHXHxVuIN5g+E+ZbsjLXbvlr2wGh2n8jsgnEFhrdEww747p6kyzwag6VkyVjHgsl+4HFajUq9I73C5VGJobqdg/QnQIalA8LFY0mp3gNOTvt9Tvcak7Z/Je/xyn1eFI/0lX+TRcZDO1tvd5oTSQdTzgnBLMIVW3m8VPJMasmQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=XnHVGFwe; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="XnHVGFwe" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1759760308; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=6VD2zsKbVIO0/etmD/GaqQQpyf9O3SbQk82/C3h0JpE=; b=XnHVGFwe11CVpLFBJTPucRAqfl7k6hReu+f1ZwxJpV/VRI4ZE93m4U33DnAFM3BUHJ0JBj H1EeFpy5PsfkzawWQxYhblxxj6Ws+6gzWtv4ZB/IKCb2rcclcAKY7JOStHlvGPf1N60xXH 5ilCnhyL6ghlmwD0nhjymZ+FiVxq0JI= Received: from mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-290-nfW2r-0WP_-7PdbSSG4qIA-1; Mon, 06 Oct 2025 10:18:25 -0400 X-MC-Unique: nfW2r-0WP_-7PdbSSG4qIA-1 X-Mimecast-MFC-AGG-ID: nfW2r-0WP_-7PdbSSG4qIA_1759760304 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id EC28B195609E; Mon, 6 Oct 2025 14:18:23 +0000 (UTC) Received: from fedora (unknown [10.72.120.2]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id AD0EC30002CC; Mon, 6 Oct 2025 14:18:17 +0000 (UTC) Date: Mon, 6 Oct 2025 22:18:12 +0800 From: Ming Lei To: Christoph Hellwig Cc: Jens Axboe , linux-block@vger.kernel.org, Mikulas Patocka , Zhaoyang Huang , Dave Chinner , linux-fsdevel@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-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 On Fri, Oct 03, 2025 at 12:06:44AM -0700, Christoph Hellwig wrote: > On Sun, Sep 28, 2025 at 09:29:25PM +0800, Ming Lei wrote: > > - there isn't any queued blocking async WRITEs, because NOWAIT won't cause > > contention with blocking WRITE, which often implies exclusive lock > > Isn't this a generic thing we should be doing in core code so that > it applies to io_uring I/O as well? No. It is just policy of using NOWAIT or not, so far: - RWF_NOWAIT can be set from preadv/pwritev - used for handling io_uring FS read/write Even though loop's situation is similar with io-uring, however, both two are different subsystem, and there is nothing `core code` for both, more importantly it is just one policy: use it or not use it, each subsystem can make its own decision based on subsystem internal. Thanks, Ming