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x-vs=clean score=-100 state=0 X-ME-VSCategory: clean X-CM-Envelope: MS4wfHu6cSnxFOWQIQN02vU5mWFn4Wyj+03fVdsC86g4r7lggk+xo9oW/0o1id1jJfsITyT1RMr0dMfPIXJwKcgDgx7uJWsfwtp6KiZSyIpesOYtJ8T9pbUq /gqbI9YAIUPpgrN65+0+ZtPFlzlraEkuNyAFyxD/FqLjOOzy9w5Z1SAhoOY6PZdL2DqLFok8O01BZwFTSuH5/mt7ww7iJdOhQ0l0OrefJ0DLp2AL6B1Qdx69 X-CM-Analysis: v=2.3 cv=FKU1Odgs c=1 sm=1 tr=0 a=UK1r566ZdBxH71SXbqIOeA==:117 a=UK1r566ZdBxH71SXbqIOeA==:17 a=kj9zAlcOel0A:10 a=VUJBJC2UJ8kA:10 a=VwQbUJbxAAAA:8 a=Za2ujYBjTRcH6WKBI0kA:9 a=CjuIK1q_8ugA:10 a=x8gzFH9gYPwA:10 a=AjGcO6oz07-iQ99wixmX:22 X-ME-CMScore: 0 X-ME-CMCategory: none Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753369AbeEVWHw (ORCPT ); Tue, 22 May 2018 18:07:52 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:49806 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753088AbeEVWHu (ORCPT ); Tue, 22 May 2018 18:07:50 -0400 Date: Tue, 22 May 2018 23:07:48 +0100 From: Al Viro To: Christoph Hellwig Cc: Avi Kivity , linux-aio@kvack.org, linux-fsdevel@vger.kernel.org, netdev@vger.kernel.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: aio poll and a new in-kernel poll API V12 Message-ID: <20180522220748.GF30522@ZenIV.linux.org.uk> References: <20180522113108.25713-1-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180522113108.25713-1-hch@lst.de> User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-api-owner@vger.kernel.org X-Mailing-List: linux-api@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Tue, May 22, 2018 at 01:30:37PM +0200, Christoph Hellwig wrote: > Hi all, > > this series adds support for the IOCB_CMD_POLL operation to poll for the > readyness of file descriptors using the aio subsystem. The API is based > on patches that existed in RHAS2.1 and RHEL3, which means it already is > supported by libaio. To implement the poll support efficiently new > methods to poll are introduced in struct file_operations: get_poll_head > and poll_mask. The first one returns a wait_queue_head to wait on > (lifetime is bound by the file), and the second does a non-blocking > check for the POLL* events. This allows aio poll to work without > any additional context switches, unlike epoll. I can live with that, modulo bug in #8 (see reply to that one). There's some nitpicking, but that can be dealt with in followups.