From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 07CF6C04AB5 for ; Thu, 6 Jun 2019 20:12:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DC3BF208C3 for ; Thu, 6 Jun 2019 20:12:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728566AbfFFUMA (ORCPT ); Thu, 6 Jun 2019 16:12:00 -0400 Received: from mx2.suse.de ([195.135.220.15]:58646 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727082AbfFFUMA (ORCPT ); Thu, 6 Jun 2019 16:12:00 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 7B49AAF8A; Thu, 6 Jun 2019 20:11:58 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Thu, 06 Jun 2019 22:11:57 +0200 From: Roman Penyaev To: Renzo Davoli Cc: Greg KH , Alexander Viro , Davide Libenzi , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, linux-kernel-owner@vger.kernel.org Subject: Re: [PATCH 1/1] eventfd new tag EFD_VPOLL: generate epoll events In-Reply-To: <20190603150010.GE4312@cs.unibo.it> References: <20190526142521.GA21842@cs.unibo.it> <20190527073332.GA13782@kroah.com> <20190527133621.GC26073@cs.unibo.it> <480f1bda66b67f740f5da89189bbfca3@suse.de> <20190531104502.GE3661@cs.unibo.it> <20190603150010.GE4312@cs.unibo.it> Message-ID: <5d44edf655e193789823094d1b4301fd@suse.de> X-Sender: rpenyaev@suse.de User-Agent: Roundcube Webmail Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Renzo, On 2019-06-03 17:00, Renzo Davoli wrote: > Hi Roman, > > I sorry for the delay in my answer, but I needed to set up a minimal > tutorial to show what I am working on and why I need a feature like the > one I am proposing. > > Please, have a look of the README.md page here: > https://github.com/virtualsquare/vuos > (everything can be downloaded and tested) Is that similar to what user-mode linux does? I mean the principle. > I am not trying to port some tools to use user-space implemented > stacks or device > drivers/emulators, I am seeking to a general purpose approach. You still intersect *each* syscall, why not to do the same for epoll_wait() and replace events with correct value? Seems you do something similar already in a vu_wrap_poll.c: wo_epoll_wait(), right? Don't get me wrong, I really want to understand whether everything really looks so bad without proposed change. It seems not, because the whole principle is based on intersection of each syscall, thus one more one less - it does not become more clean and especially does not look like a generic purpose solution, which you seek. I may be wrong. -- Roman