From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Hounschell Subject: Re: Hard real time in user space with preempt_rt patch Date: Tue, 24 Apr 2012 04:57:32 -0400 Message-ID: <4F966AFC.7070803@cfl.rr.com> References: Reply-To: dmarkh@cfl.rr.com Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: linux-rt-users@vger.kernel.org To: Anisha Kaul Return-path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.120]:32521 "EHLO cdptpa-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755632Ab2DXI5e (ORCPT ); Tue, 24 Apr 2012 04:57:34 -0400 In-Reply-To: Sender: linux-rt-users-owner@vger.kernel.org List-ID: On 04/24/2012 01:46 AM, Anisha Kaul wrote: > From: https://rt.wiki.kernel.org/articles/f/r/e/Frequently_Asked_Questions_7407.html > >> Real-time only has impact on the kernel; Userspace does not notice the difference except for better real time behavior. > > Does it mean that if we write the applications in user space, they > won't get the hard real time effect? > The threads running in the userspace won't get the hard real time effect? > You use the term "hard real time". The RT patch set does not even come close to providing a "hard real time" environment, and isn't even attempting to. It does however provide user land applications a much better chance for a "soft real time" environment. The phrase you quot above just means the patches are applied to the kernel and there are no patches required for user land glibc or your application. Regards Mark