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Make File error
by Anil Joshi Dec. 4, 2013

Dec. 4, 2013

Hi All, I have an make file like this obj-m := abc.o all: make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules clean: make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean when i do the make i am getting this error *make: Nothing to be done for `all'.* *I am using centos 6.2uname -aLinux hwcentos2 2.6.32-220.el6.x86_64 #1 SMP Tue Dec 6 19:48:22 GMT 2011 x86_64 x86_64 x86_64 GNU/Linux* Whats the error? Regards Anil

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Issue while unloading modules via modprobe
by Chetan Nanda Dec. 3, 2013

Dec. 3, 2013

Hi, I am getting an error while unloading modules via modprobe. Here is the description of issue. I have a module 'A' that depends on Module 'C' and 'D'. And another module 'B' that depends on Module 'C' and 'E' I loaded these modules from code via 'system' function as error = system("modprobe -v A"); error = system("modprobe -v B"); After this all my modules A, B, C, D, and E are loaded properly. Now when i tried to unload module A via error = system("modprobe -rv A"); This returns an error = 256. But my module A and D is unloaded successfully. 'C' is not unloaded as it is still in used by 'B'. Is the error returned by system function is caused due to not unloading of module 'C'? This is a valid scenario and error should not have returned in this case. I am still trying to find the reason for an error. If anyone has some information on this then please help to share. Thanks, Chetan Nanda

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module vs main kernel
by Abu Rasheda Dec. 3, 2013

Dec. 3, 2013

I have my implementation of socket APIs, I sock_unregister(AF_INET); & sock_register(&inet_family_ops), this replaces kernel resident socket related calls with my socket related calls. My code is loaded as kernel module. My question, is Linux kernel able to call its own socket call more efficiently (less overhead, fewer CPU cycles) than mine ? code is running on Intel x86_64 arch. Any pointer is appreciated.

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Open source networking Projects
by Robert Clove Nov. 29, 2013

Nov. 29, 2013

Hi All, I am a new (sort of fresher) and want to do some work in networking domain like network device driver or some changes that increase the network performance and all. Could you please suggest me some projects if they are new it would be good and easy to understand. Thanks

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bio_add_page
by neha naik Nov. 28, 2013

Nov. 28, 2013

Hi, On the block device driver i am writing : I have a bio such that the bvec has a page with bvec->bv_len = 4096. I want to create two bios with this bvec such that bio1 --> contains 7 sectors(len1) bio2 --> contiains 1 sector(len2) I tried using bio_add_page as follows : bio_add_page(bio1, bvec->bv_page, len1, bvec->bv_offset) bio_add_page(bio2, bvec->bv_page, len2, bvec->bv_offset + len1) But my second 'bio_add_page' returns 0 and not len2 indicating that there is something wrong. Is there some other way to do this??? Regards, Neha

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How to contribute to latest -rc kernel?
by Arvid Brodin Nov. 28, 2013

Nov. 28, 2013

Hi, How would I go ahead to send a patch for the latest -rc kernel? Specifically: * What tree to diff against? (Linus'?) * To which list do I send the patch? Background: I've contributed a new network driver that is now in 3.13-rc1. I would like to fix it so that it behaves better with iproute. Strictly speaking this isn't a bug fix, but the driver is going to be quite useless without iproute support, and that won't be there until this fix is in the kernel. -- Arvid Brodin | Consultant (Linux) ALTEN | Knarrarnäsgatan 7 | SE-164 40 Kista | Sweden arvid.brodin(a)alten.se | www.alten.se/en/ ________________________________ Xdin is changing its name. From 25 November 2013 we will be known as Alten. Read more at www.alten.se

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Kernel Memory management
by manty kuma Nov. 28, 2013

Nov. 28, 2013

Here is an interesting question(not mine) in SO related to Kernel memory management. Most of the points are my questions aswell. It needs ex[ert comments. could we try to answer questions posted there. http://stackoverflow.com/questions/20041212/does-virtual-memory-area-struct…

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Major and minor numbers
by Nav Kamal Nov. 28, 2013

Nov. 28, 2013

Am a little stuck at major and minor numbers used to reference the connection between device file and device driver. Can please somebody theoretically explain how they work ? Regards, Navkamal Rakra

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zswap compressors
by Thomas Krichel Nov. 26, 2013

Nov. 26, 2013

Hi, I have two issues with zswap. I am running 3.11.0-13-generic #20~precise2-Ubuntu. The zswap doc says that I can run a custom compessor and suggests, as an example in the doc to use, for example, zswap.compressor=deflate as a kernel option. But when I do that dmesg says "zswap: deflate compressor not available" and send me back to the default lzo compressor. Trying lz4 gets the same note. Is this a bug or a feature, and where should this be reported to? I wonder why the default compressor is lzo. I understand that, roughly, lz4 would achieve roughly the same compression and takes roughly the same effort to compress, but decompresses much faster. If my understanding is correct, a compressed page is likely to be decompressed several times while it stays in the pool. I therefore suspect that lz4 it would be a better compressor for zswap than lzo. Am I way off base here? -- Cheers, Thomas Krichel http://openlib.org/home/krichel skype:thomaskrichel

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Re: Major and minor numbers
by Anuz Pratap Singh Tomar Nov. 26, 2013

Nov. 26, 2013

On Tue, Nov 26, 2013 at 1:15 PM, Nav Kamal <navkamal90(a)gmail.com> wrote: > Thanks but am already studying from this book. What I understand from > this is every driver is associated with a device and each of this relation > has a unique major number associated with it and every device has a unique > minor number which a kernel uses to reference it. Am I correct ? > > Please always cc kernelnewbies in reply. Do not top post(http://catb.org/jargon/html/T/top-post.html) I would suggest reading this article about udev, things have changed a bit http://www.linux.com/news/hardware/peripherals/180950-udev > Regards, > Navkamal Rakra > On Nov 26, 2013 6:33 PM, "Anuz Pratap Singh Tomar" < > chambilkethakur(a)gmail.com> wrote: > >> >> >> >> On Tue, Nov 26, 2013 at 11:06 AM, Nav Kamal <navkamal90(a)gmail.com> wrote: >> >>> Am a little stuck at major and minor numbers used to reference the >>> connection between device file and device driver. Can please somebody >>> theoretically explain how they work ? >>> >> http://www.makelinux.net/ldd3/chp-3-sect-2 >> >>> Regards, >>> Navkamal Rakra >>> >>> _______________________________________________ >>> Kernelnewbies mailing list >>> Kernelnewbies(a)kernelnewbies.org >>> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies >>> >>> >> >> >> -- >> Thank you >> Warm Regards >> Anuz >> > -- Thank you Warm Regards Anuz

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