From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932311AbVI2Xu1 (ORCPT ); Thu, 29 Sep 2005 19:50:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932370AbVI2Xu1 (ORCPT ); Thu, 29 Sep 2005 19:50:27 -0400 Received: from web34103.mail.mud.yahoo.com ([66.163.178.101]:40793 "HELO web34103.mail.mud.yahoo.com") by vger.kernel.org with SMTP id S932311AbVI2Xu0 (ORCPT ); Thu, 29 Sep 2005 19:50:26 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:Received:Date:From:Subject:To:Cc:In-Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding; b=NOIvYuYBuSMmIZlykPRu72IFsnFmkY2RcdVZsKh55ESvI98hNaqKLWl+0owVAqCbIZvpbsIJLZ/EL97cq+JvPqCkMo5o+q5jNxACxtOX5B73dQV/7kw0XydO1SCDJvpsyEpI/PAQoYFVC6YOHHbJ06Cs+yxOajn2mP0nKA5usF4= ; Message-ID: <20050929235025.13166.qmail@web34103.mail.mud.yahoo.com> Date: Thu, 29 Sep 2005 16:50:25 -0700 (PDT) From: Wilson Li Subject: Re: Slow loading big kernel module in 2.6 on PPC platform To: "linux-os \(Dick Johnson\)" Cc: linux-kernel , Samuel Masham In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org >--- "linux-os (Dick Johnson)" wrote: > > On Wed, 28 Sep 2005, Wilson Li wrote: > > I have a module I am currently working on. It has some assembly > stuff linked with it, so it was easy to modify. In the assembly > I allocated 16 megabytes of static storage (using the .space > keyword), > first in the .data section, then in .rodata, then in .text. The > .text section is where code exists. In no case did the module take > more than 1/4 second to load. In all cases the size shown by > `lsmod` > reflected the enormous size of the module. > > Now, that's static storage. If your code uses kmalloc() and > friends to allocate a lot of storage when it is being loaded, > then that's a different story. FYI, when you see a kernel message > on the screen, that's not necessarily when it was "printed". It > gets buffered, you know. If you want to time-check when various > sections get control, to find out what's eating the time, then > put the jiffie count into your kernel messages. > > A simple macro using the __FUNCTION__ string and the jiffie > count can go a long way towards finding out what's happening. > > For instance, I once had a problem with continuous interrupts > from a device, that couldn't be cleared, until the device was > initialized. That slowed the system to a stand-still until > I found that. The fix was easy, do some initialization before > attaching the interrupt, at least enough to quiet the board. > This board had an empty FPGA, whos bits need to be loaded > with a bit-banger to make it work. The pin connected to an > interrupt was just whatever-it-was-from-the-factory, before > the intelligence was loaded. That system took about a minute > for the first kernel message to be printed. Sometimes the > system was very quiet and needed to be kicked. > > > Cheers, > Dick Johnson > Penguin : Linux version 2.6.13 on an i686 machine (5589.55 > BogoMips). > Warning : 98.36% of all statistics are fiction. > > **************************************************************** > The information transmitted in this message is confidential and may > be privileged. Any review, retransmission, dissemination, or other > use of this information by persons or entities other than the > intended recipient is prohibited. If you are not the intended > recipient, please notify Analogic Corporation immediately - by > replying to this message or by sending an email to > DeliveryErrors@analogic.com - and destroy all copies of this > information, including any attachments, without reading or > disclosing them. > > Thank you. Appreciate your advice and help. I finally tracked it down to the function called in init_module() in kernel/module.c. /* Allow arches to frob section contents and sizes. */ err = module_frob_arch_sections(hdr, sechdrs, secstrings, mod); which takes most of time (more then 99%) during module loading just as the reply from Semuel earlier. Wilson Li __________________________________ Yahoo! Mail - PC Magazine Editors' Choice 2005 http://mail.yahoo.com