From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from verein.lst.de ([213.95.11.211]:35522 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932204AbeAHKpP (ORCPT ); Mon, 8 Jan 2018 05:45:15 -0500 Date: Mon, 8 Jan 2018 11:45:13 +0100 From: Christoph Hellwig To: Al Viro Cc: Christoph Hellwig , Avi Kivity , linux-aio@kvack.org, linux-fsdevel@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 03/31] fs: introduce new ->get_poll_head and ->poll_mask methods Message-ID: <20180108104513.GB5797@lst.de> References: <20180104080043.14506-1-hch@lst.de> <20180104080043.14506-4-hch@lst.de> <20180106191242.GI21978@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180106191242.GI21978@ZenIV.linux.org.uk> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Sat, Jan 06, 2018 at 07:12:42PM +0000, Al Viro wrote: > On Thu, Jan 04, 2018 at 09:00:15AM +0100, Christoph Hellwig wrote: > > ->get_poll_head returns the waitqueue that the poll operation is going > > to sleep on. Note that this means we can only use a single waitqueue > > for the poll, unlike some current drivers that use two waitqueues for > > different events. But now that we have keyed wakeups and heavily use > > those for poll there aren't that many good reason left to keep the > > multiple waitqueues, and if there are any ->poll is still around, the > > driver just won't support aio poll. > > *UGH* > > Gotta love the optimism, but have you actually done the conversion? > I'm particularly suspicious about the locking rules here... I've done just about everything but random drivers. Which is the ones where people care about performance and thus aio poll. I suspect that we will have various odd cruft drivers that will be left alone. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH 03/31] fs: introduce new ->get_poll_head and ->poll_mask methods Date: Mon, 8 Jan 2018 11:45:13 +0100 Message-ID: <20180108104513.GB5797@lst.de> References: <20180104080043.14506-1-hch@lst.de> <20180104080043.14506-4-hch@lst.de> <20180106191242.GI21978@ZenIV.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Christoph Hellwig , Avi Kivity , linux-aio@kvack.org, linux-fsdevel@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: Al Viro Return-path: Content-Disposition: inline In-Reply-To: <20180106191242.GI21978@ZenIV.linux.org.uk> Sender: owner-linux-aio@kvack.org List-Id: netdev.vger.kernel.org On Sat, Jan 06, 2018 at 07:12:42PM +0000, Al Viro wrote: > On Thu, Jan 04, 2018 at 09:00:15AM +0100, Christoph Hellwig wrote: > > ->get_poll_head returns the waitqueue that the poll operation is going > > to sleep on. Note that this means we can only use a single waitqueue > > for the poll, unlike some current drivers that use two waitqueues for > > different events. But now that we have keyed wakeups and heavily use > > those for poll there aren't that many good reason left to keep the > > multiple waitqueues, and if there are any ->poll is still around, the > > driver just won't support aio poll. > > *UGH* > > Gotta love the optimism, but have you actually done the conversion? > I'm particularly suspicious about the locking rules here... I've done just about everything but random drivers. Which is the ones where people care about performance and thus aio poll. I suspect that we will have various odd cruft drivers that will be left alone. -- To unsubscribe, send a message with 'unsubscribe linux-aio' in the body to majordomo@kvack.org. For more info on Linux AIO, see: http://www.kvack.org/aio/ Don't email: aart@kvack.org