From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: linux-rt-users-owner@vger.kernel.org Received: from mail-wm0-f67.google.com ([74.125.82.67]:40852 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727877AbeHVMNb (ORCPT ); Wed, 22 Aug 2018 08:13:31 -0400 Received: by mail-wm0-f67.google.com with SMTP id 207-v6so1336545wme.5 for ; Wed, 22 Aug 2018 01:49:35 -0700 (PDT) Date: Wed, 22 Aug 2018 10:49:30 +0200 From: Juri Lelli Subject: Re: SCHED_DEADLINE as user Message-ID: <20180822084930.GA27801@localhost.localdomain> References: <20180817102810.GC27071@localhost.localdomain> <513fd544-bc51-7ea6-8b94-983d28922a66@klingt.org> <20180820085420.GB8866@localhost.localdomain> <4c58c94c-d99d-9f08-a5a3-710defc612c8@bristot.me> <05fbd5a4-f354-e084-cf40-8488548d7cb1@klingt.org> <20180821073834.GA24428@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180821073834.GA24428@localhost.localdomain> Sender: linux-rt-users-owner@vger.kernel.org List-ID: To: Tim Blechmann Cc: Daniel Bristot de Oliveira , linux-rt-users@vger.kernel.org, Tommaso Cucinotta , Luca Abeni , Alessio Balsini On 21/08/18 09:38, Juri Lelli wrote: > On 21/08/18 00:45, Tim Blechmann wrote: > > [...] > > > apart from that, i'm only missing two features: > > > > * using SCHED_DEADLINE from user applications is kind of a showstopper > > for me > > Right. Would you be up for continuing experimenting with DEADLINE (while > we get our heads around removing this constraint) by - ugly hack warning > - removing the check at > > https://elixir.bootlin.com/linux/latest/source/kernel/sched/core.c#L4216 > > ? > > I guess it would be good if you could provide even more feedback than > you already did, so that we can plan ahead what needs fixing/changing or > implementing. > > BTW, thanks a lot already for this discussion! :-) > > > * a nicer glibc wrapper, that allows me to use pthreads rather than > > using `syscall`: it's all pretty easy to obtain the `tid` for a calling > > thread (gettid), but it seems to be impossible to obtain the `tid` from > > `pthread_t` without some hacks which are way too dirty to share in > > public ... > > Indeed. We have been basically relying on > > https://github.com/scheduler-tools/rt-app/tree/master/libdl > > so far. But, I guess it's time - it has been time for a while - that we > reach glibc guys and try to understand why this is not yet all in the > standard libraries. FYI, I added both points to the list of known issues. Feel free to add details. https://github.com/jlelli/linux/issues Best, - Juri