August 2011 - kernelnewbies@kernelnewbies.org

Is it needed to reinstall custom kernel every time, after rebuilding?
by Amirali Shambayati Aug. 19, 2011

Aug. 19, 2011

Hi all, Last time, I emailed to linux-kernel and kernenewbies mailing-lists about how to speed up kernel compilation. I received very useful peace of advice about using "ccache". Now I want to modify and compile a unique custom kernel several times. I used https://help.ubuntu.com/community/Kernel/Compile to compile custom kernel. This tutorial uses "kpkg" command to build kernel and it produces two .deb files: "linux-image" and "linux-header" as result. So for the first time I followed this tutorial. For next times, according to to experts' advice, I use "make all" in custom kernel root directory to rebuild kernel. I am not sure that it would be enough to use changed kernel after rebooting. As I asked from some experts, It is also required to install kernel again, but they were not familiar with "kpkg" and "dbkg",... commands for kernel installation. Should I use "dbkg" command after every time I rebuild kernel, for re-installation? If anybody is familiar with these method of kernel installation, please help me. It is very urgent, because it is related to my B.S. thesis :P Regards, -- Amirali Shambayati Bachelor Student Computer Engineering Department Sharif University of Technology Tehran, Iran

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Re: Is it needed to reinstall custom kernel every time, after rebuilding?
by Mulyadi Santosa Aug. 19, 2011

Aug. 19, 2011

On Fri, Aug 19, 2011 at 01:02, Amirali Shambayati <amirali.shambayati(a)gmail.com> wrote: > Would you say, I got what you mean right or not? Because I have very > restricted time to present my BS. thesis:-s I am not really sure I really catch what you mean by "reinstall" :) IMO reinstall is only a proper term when related to package management. So, I think if you have to use the term "reinstall", perhaps you confuse it with package management ? Sorry, maybe you're under pressure but I can't help much with that. -- regards, Mulyadi Santosa Freelance Linux trainer and consultant blog: the-hydra.blogspot.com training: mulyaditraining.blogspot.com

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ohci_hcd leak ed
by DiP Aug. 18, 2011

Aug. 18, 2011

Hi all When I take my two sonix-based webcams to my box, and started vlc on both I got <code> Aug 19 02:14:45 mixer kernel: [ 558.384176] ohci_hcd 0000:00:0b.0: leak ed f53dd580 (#81) state 2 [repeated many times...] Aug 19 02:14:45 mixer kernel: [ 558.406651] gspca: no transfer endpoint found </code> That with standard archlinux kernel 3.0 Linux mixer 3.0-ARCH #1 SMP PREEMPT Sat Aug 6 16:49:00 CEST 2011 i686 Mobile AMD Sempron(tm) Processor 3800+ AuthenticAMD GNU/Linux Also I got almost the same with my other box (kernel is hand-compiled) Linux di 3.0.1-pf-di #10 SMP PREEMPT Wed Aug 17 19:23:37 EEST 2011 x86_64 Intel (R) Core(TM)2 Duo CPU E8200 @ 2.66GHz GenuineIntel GNU/Linux Aug 18 23:36:37 di kernel: gspca: no transfer endpoint found Aug 18 23:36:38 di kernel: gspca: no transfer endpoint found Aug 18 23:37:22 di kernel: gspca: no transfer endpoint found Aug 18 23:37:23 di kernel: gspca: no transfer endpoint found With that (hand-compiled kernel) Linux belu4ka 2.6.38-pf7-nusq #1 SMP PREEMPT Thu May 5 11:27:48 EEST 2011 i686 Mobile AMD Sempron(tm) Processor 3800+ AuthenticAMD GNU/Linux I got Aug 19 00:30:13 belu4ka kernel: [ 353.140330] gspca: bandwidth not wide enough - trying again Aug 19 00:30:13 belu4ka kernel: [ 353.409184] ohci_hcd 0000:00:0b.0: leak ed f560c400 (#81) state 2 modules: gspca_sonixb 10863 0 gspca_main 19539 1 gspca_sonixb webcams: idVendor=0c45, idProduct=60b0 idVendor=0c45, idProduct=6029 The problem persists only when I make vlc show me both cams in the same time. Video from the first camera started still displayed, but the second cam is switched off. I wonder if somebody tell me if I should bugreport that and where to do that? I didn`t found anything similar to my problem in linux-usb, linux-video and linux-kernel lists? //D

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Proc fs Guide
by Ezequiel García Aug. 18, 2011

Aug. 18, 2011

Hi, Pardon for the newbie question, but since this is newbie forum anyway, here it goes Is this guide http://buffer.antifork.org/linux/procfs-guide.pdf (2001) updated (or outdated)? Is proc suffering any movement? I heard the prefered way to comunicate is sysfs, but I am working on a dated embedded environment and sysfs is not present. Btw, I am into that because I need to know the overall thread count. Greetings!

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PCI IO memory resource allocation
by J.Hwan Kim Aug. 18, 2011

Aug. 18, 2011

Hi, everyone In kernel source, where is the PCI IO memory resource allocation is done? (memory mapped io) And can you explain the IO memory resource allocation mechanism? Thanks in advance Best Regards, J.Hwan Kim

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How to reinstall modified custom kernel?
by Amirali Shambayati Aug. 18, 2011

Aug. 18, 2011

Hi all, Last time, I emailed to linux-kernel and kernenewbies mailing-lists about how to speed up kernel compilation. I received very useful peace of advice about using "ccache". Now I want to modify and compile a unique custom kernel several times. I used https://help.ubuntu.com/community/Kernel/Compile to compile custom kernel. This tutorial uses "kpkg" command to build kernel and it produces two .deb files: "linux-image" and "linux-header" as result. So for the first time I followed this tutorial. For next times, according to to experts' advice, I use "make all" in custom kernel root directory to rebuild kernel. I am not sure that it would be enough to use *changed kernel* after rebooting. As I asked from some experts, It is also required to install kernel again, but they were not familiar with "kpkg" and "dpkg",... commands for kernel installation. Should I use "dbkg" command after every time I rebuild kernel, for re-installation? If anybody is familiar with these method of kernel installation, please help me. It is very urgent, because it is related to my B.S. thesis :P Regards, -- Amirali Shambayati Bachelor Student Computer Engineering Department Sharif University of Technology Tehran, Iran

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Query about the realtime processes scheduling.
by nilesh Aug. 18, 2011

Aug. 18, 2011

Hi, I am not too familiar with Linux scheduler. What I could understand theoretically is - the interactive processes get advantage (-5) in priority. And hence the effective priority is higher. Query: Is this true for realtime processes ( with SCHED_FIFO/SCHED_RR policy) as well? Could the realtime processes be I/O bound or interactive? -- Thanks, Nilesh

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how to enable linux box to dump crash image on local disk
by amit mehta Aug. 18, 2011

Aug. 18, 2011

I've a Linux box which is crashing under a particular test scenario. To debug this issue I was thinking of using the crash (man 8 crash) utility (available by default on recent releases of RHEL and SuSE) . This tool requires the kernel crash dump (vmcore) and the debugging symbols. On my machine, I don't see any crash under /var/crash, Hence please let me know the configuration changes which i need to do to enable my machine to dump the kernel image locally (do i need to apply diskdump patches and rebuild the kernel??) whenever there is a kernel crash. Kdump seem to be another tool for this job but that requires a lot of setup. Is there a *shortcut* to enable kernel crash dump facility ? The debugging symbols can be found here: http://ftp.riken.go.jp/Linux/slc/slc6X/updates/x86_64/debug/ http://ftp.riken.go.jp/Linux/slc/slc6X/updates/i386/debug/ -Amit

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Thunderbolt and Mac Book Pro
by Greg Freemyer Aug. 17, 2011

Aug. 17, 2011

Can anyone tell me the status of the linux kernel getting Thunderbolt support for the latest Mac Book Pro? I like to carry a boot CD with me that can boot PCs including Macs. I haven't had much issue in the paxt, but apparently the latest Mac Book Pro's are using new technology that is not yet commonly supported. Thanks Greg

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export atomic64_t into /proc/sys/
by LovelyLich Aug. 16, 2011

Aug. 16, 2011

Hello everyone, In my module, there is an atomic64_t counter for something , such as packets received by Ethernet card. What I want to do is to export this atomic64_t number into /proc/sys/net/ipv4/. The question is atomic64_t is an 64-bit long integer which is not support by kernel's default proc_handlers like proc_dointvec(), proc_dointvec_minmax() and so on. So, Do I have to implement one proc_handler to handle this 64-bit integer? Or you have some better ideas? Any reply will be appreciated and Thanks in advanced.

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