Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753543AbaBCWCI (ORCPT ); Mon, 3 Feb 2014 17:02:08 -0500 Received: from dcvr.yhbt.net ([64.71.152.64]:57697 "EHLO dcvr.yhbt.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750789AbaBCWCH (ORCPT ); Mon, 3 Feb 2014 17:02:07 -0500 X-Greylist: delayed 612 seconds by postgrey-1.27 at vger.kernel.org; Mon, 03 Feb 2014 17:02:07 EST Date: Mon, 3 Feb 2014 21:51:51 +0000 From: Eric Wong To: Andy Lutomirski Cc: Nathaniel Yazdani , Al Viro , Linux FS Devel , "linux-kernel@vger.kernel.org" Subject: Re: [RFC PATCH 0/3] epoll: read(),write(),ioctl() interface Message-ID: <20140203215151.GA25594@dcvr.yhbt.net> References: <1391393832-8754-1-git-send-email-n1ght.4nd.d4y@gmail.com> <52EFEF0A.9080101@amacapital.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Andy Lutomirski wrote: > >> On 02/02/2014 06:17 PM, Nathaniel Yazdani wrote: > > So are you saying that those features you mentioned are specifically sought > > after for the kernel? If so I'd like to take a crack at some of them, > > may as well > > get some use out of my new knowledge of epoll internals :) > > If by "sought after", you mean "is there at least one epoll user who > wants them", then yes :) > > I think that EPOLLET and EPOLLONESHOT are giant hacks, and that what > everyone really wants is the ability to very efficiently toggle events > on and off. The ability to do it simultaneously and inexpensively > with epoll_wait would make it happen. Everybody using single-threaded epoll, you mean? I suppose there's quite a few of those. I've pondered an epoll_xchg syscall which would behave like *BSD kevent to satisfy single-threaded users, but never got around to it. All my epoll uses are multithreaded w/ oneshot nowadays, so xchg would only save one syscall per thread. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/