April 2014 - kernelnewbies@kernelnewbies.org - Kernelnewbies Mailing Lists

Hi, a question about sending patches to lkml
by Jianyu Zhan April 22, 2014

April 22, 2014

Hi,all I have a pile of patches to send. It involves several subsystems, but not all patches are all subsystem related. So 1) should I send all emails to all subsytems or just 2) send the related ones to correspoding mail-list and all to lkml. I am now using git-send-email, it seems it choose 1). Any suggestion? I think 1) is good, by maybe to noisy for those who only cares their subsys-related parts. Thanks, Jianyu Zhan

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slicoss: a hardware debugging question
by David Matlack April 22, 2014

April 22, 2014

I've been working on the staging slicoss driver (for an ethernet NIC). I haven't been able to find any detailed documentation about the card online, all I have is the source code. During the PCI probe routine slic_entry_probe(), the driver attempts to load some configuration data from the card. The driver disables interrupts from the deviece and polls the ISR which signals the completed transfer. The relevant code is in drivers/staging/slicoss/slicoss.c:slic_card_init: [...] slic_config_get(adapter, phys_configl, phys_configh); for (;;) { if (adapter->pshmem->isr) { [...] } else { mdelay(1); i++; if (i > 5000) { dev_err(&adapter->pcidev->dev, "%d config data fetch timed out!\n", adapter->port); [...] } } } [...] The only problem is, this times out more than half the time. And when it succeeds, it [seemingly] always takes 22 cycles. I have tried increasing 5000 to various higher numbers (up to 50000) with no effect. I thought it might be a compiler optimization or coherence issue so I threw a mb() in the loop and that seemed to have no effect as well. Any recommendations on debugging? Thanks. --David

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append device tree to powerpc kernels
by srinivas bakki April 21, 2014

April 21, 2014

Hi, Is there a way to append device tree blob to the powerpc kernels like i found with ARM ? I do not get the boot options to select : "Use appended device tree blob to zImage" option at all in the powerpc config files. TIA Srinivas

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Re: Help needed to use git send-email utility
by Abhijeet April 21, 2014

April 21, 2014

Hi Rahul, Please see this video of GKH https://www.youtube.com/watch?v=LLBrBBImJt4 He has explained everything nicely. Thanks, -- Abhijeet Kasurde

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Eudyptula Challenge and gmail
by Ritesh Ranjan April 21, 2014

April 21, 2014

Hi, I was trying to implement the task 1 and send the mail using gmail, but I got a reply that I can't use base64 encoding for my attachment. So I switched over to mutt to send the email [still using my gmail account] and send the mail again. I checked the email source and saw that It's not encoded. Content-Type: text/x-csrc; charset=us-ascii Content-Disposition: attachment; filename="task1.c" #include <linux/module.h> #include <linux/kernel.h> There has been no reply since. Not even telling me that I have done something wrong. I have waited for almost a day. Is there something wrong in the way I have gone about it, or is the dealy to be expected. Could someone, who has been successful in sending a result and getting a reply, summarize the methods they've used to submit a result [preferably using a gmail account and mutt]. Thanks, Ritesh Ranjan

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high resolution timers and timer interrupt thrashing
by Sudharsan vijayaraghavan April 21, 2014

April 21, 2014

Hi All, With CONFIG_HIGH_RES_TIMERS configured and a whole lot of timer_create with interval of less than jiffy (i.e., few nano seconds) we are bound to get timer interrupts less than a jiffy because set_next_event will configure for expires less than jiffy. This means we are thrashing the system with more timer interrupts, perhaps to extent of almost every clock tick, is my understanding correct? Given this is it not dangerous to configure CONFIG_HIGH_RES_TIMERS Please give your thoughts Thanks, Sudharsan

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Help needed to use git send-email utility
by Rahul Garg April 21, 2014

April 21, 2014

Hi All, Like many people here, I am also taking Eudyptula Challlenge, But for last 1 week, I am stuck at level 8. I am stuck because I dont know how to send email using git. I have to send some thing like this : [xyz] Task 08 results └─>[xyz] [PATCH 01/02] Task 08: add jiffies file └─>[xyz] [PATCH 02/02] Task 08: add foo file I have tried following links: http://www.freedesktop.org/wiki/Software/PulseAudio/HowToUseGitSendEmail/ http://alblue.bandlem.com/2011/12/git-tip-of-week-patches-by-email.html http://git-scm.com/docs/git-send-email But I still unable to understand it properly. So anyone can help me with this, would be great. Regards Rahul

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RE: Help needed to use git send-email utility
by Anand Arumugam April 21, 2014

April 21, 2014

Look at MUA-SPECIFIC HINTS section at the following link: http://git-scm.com/docs/git-format-patch -----Original Message----- From: Rahul Garg Sent: 4/20/2014 7:04 PM To: kernelnewbies(a)kernelnewbies.org Subject: Help needed to use git send-email utility Hi All, Like many people here, I am also taking Eudyptula Challlenge, But for last 1 week, I am stuck at level 8. I am stuck because I dont know how to send email using git. I have to send some thing like this : [xyz] Task 08 results └─>[xyz] [PATCH 01/02] Task 08: add jiffies file └─>[xyz] [PATCH 02/02] Task 08: add foo file I have tried following links: http://www.freedesktop.org/wiki/Software/PulseAudio/HowToUseGitSendEmail/ http://alblue.bandlem.com/2011/12/git-tip-of-week-patches-by-email.html http://git-scm.com/docs/git-send-email But I still unable to understand it properly. So anyone can help me with this, would be great. Regards Rahul _______________________________________________ Kernelnewbies mailing list Kernelnewbies(a)kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

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(no subject)
by Amber Thrall April 21, 2014

April 21, 2014

I recently built and installed kernel version 3.15.0-rc1 following the KernelBuild article on kernelnewbies.org. Everything went smooth and my system is running fine. However when performing an update via (sudo yum update) the dependencies failed requiring "kernel-devel-uname-r=3.13.10". uname-r returns "3.15.0-rc1" as expected. Is there a way to get yum to recognize the latest kernel I built? Or does that require updating the kernel's source RPM? I'm running Fedora 20 and am new to kernel building. Yum's error message is included below: Error: Package: 10:buildsys-build-rpmfusion-kerneldevpkgs-current-20-19.x86_64 (rpmfusion-free-updates) Requires: kernel-devel-uname-r = 3.13.10-200.fc20.x86_64 Installed: kernel-devel-3.11.10-301.fc20.x86_64 (@anaconda) kernel-devel-uname-r = 3.11.10-301.fc20.x86_64 Installed: kernel-devel-3.13.9-200.fc20.x86_64 (@updates) kernel-devel-uname-r = 3.13.9-200.fc20.x86_64 You could try using --skip-broken to work around the problem You could try running: rpm -Va --nofiles --nodigest

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Fwd: LINUX KERNEL
by Saurabh Jain April 20, 2014

April 20, 2014

Hello everyone! I will be thankful if anyone read this mail. I was reading one of "HOWTO" article "*Implementing a System Call on Linux 2.6 for i386*" http://www.tldp.org/HOWTO/html_single/Implement-Sys-Call-Linux-2.6-i386/ I am a B.Tech computer science student and new to Linux kernel. I am following a book *"Understanding Linux kernel 3rd edition " by Bovet and Cesati*. As your time is much much important so i am writing the purpose of this mail in points : 1. I want to understand and implement process basics , how system calls works , inter process communication , *adding new system calls and interfaces in API , adding new functions to "libc and call these interfaces and system calls from user program" * etc. 2. The method you told does not add anything to API or libc , i want to implement system call through API or glibc , so that there will be no need of creating "testmycall.h" (header file ) while writing a test file to test newly created system call. 3. How the Linux kernel interact with the hardware (i want to go in such a detail so that i can make such a customizable Linux kernel so that i can use that kernel to open my home door , its a example only , i want to understand and use it to perform my experiments) I think you have got the purpose of this mail , so ITS HUMBLE REQUEST CAN YOU TELL ME THE DIRECTION WHERE I SHOULD MOVE , ANY BOOK TO UNDERSTAND THESE BASICS SPECIALLY *ADDING SYSTEM CALL USING API / LIBC *, ANY LINK YOU HAVE AND ANY FORUM WHERE I CAN POST QUESTIONS . Thank you so much for your kind help. SAURABH JAIN

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