From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arjan van de Ven Subject: Re: Boot time: Kernel start parallelization issue? Date: Sat, 15 Jan 2011 07:41:40 -0800 Message-ID: <4D31C034.8040105@linux.intel.com> References: <4D315D86.40401@googlemail.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4D315D86.40401@googlemail.com> Sender: linux-embedded-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: Dirk Behme Cc: linux-embedded@vger.kernel.org, Greg KH , Martin Mueller On 1/15/2011 12:40 AM, Dirk Behme wrote: > > There are some reports [1] [2] looking at the boot time of embedded > (ARM?) systems using initcall debug [3]. Both reports seem to show > that they have issues with the start up sequence of the kernel being > completely single-threaded. In [2] Greg mentions that on a x86 box > multi-threads are happening and that there he doesn't see this issue. > On the other hand, both reports mention Arjan's async initcall patches > [4] to help against the issue. I.e. introducing some parallelization > (on ARM) does help, too. > > With this, I wonder > > - if anybody faces similar issues with single-threaded only kernel > start on embedded (ARM?) systems? Or if this is known? Or if there are > fixes for this? > > - if we somehow should try to 're-activate' Arjan's async initcall > patches? those patches are obsoleted by the merged async_schedule() calls. what kernel are you seeing issues on? if it's something ancient, you should update first.