- kernelnewbies@kernelnewbies.org - Kernelnewbies Mailing Lists

Re: final year project
by Mulyadi Santosa Dec. 29, 2010

Dec. 29, 2010

Hi.. On Tue, Dec 28, 2010 at 13:43, madhavan raghavan <coolmaddy999(a)gmail.com> wrote: > hi > > Its a gr8 project title , I am good at c programming . can > someone guide me to do this BF scheduler project , just a guide to > where to start and go on . Please keep the kernelnewbies address intact, ok? since this is not private talk :) Where to start? Why not go to the website and download the patch and start using it? Your best mentor in this case should be no other than Mr Con Kolivas himself :) -- regards, Mulyadi Santosa Freelance Linux trainer and consultant blog: the-hydra.blogspot.com training: mulyaditraining.blogspot.com

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A doubt regarding submit_bio()
by Gaurav Mahajan Dec. 29, 2010

Dec. 29, 2010

Hello all, I am working on a operation in which I need to assure the order of bio_end_io() functions. Consider the scenario, If I submit two bio requests using submit_bio() function one after another, then is there any guarantee that the bio_end_io() for the bios will be invoked in the same order in which I submitted the bios? Basically I mean to say, would the generic block layer or I/O scheduler maintain the order of bios submitted to them? Hoping for some help. Regards, Gaurav.

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Re: looking for corrections/enhancements/omissions for LKD3
by Raahi Mehra Dec. 29, 2010

Dec. 29, 2010

Hi Robert, Just so you know, Jonathan Corbet of "LDD" fame has written a review of LKD3 on lwn.net. He has done some very interesting observations on the book and mentioned that some parts are completely obsolete. If you care to check, heres the link: "http://lwn.net/Articles/419855/#Comments" Some excerpts from that article: *"Linux Kernel Development is, at this time, probably the best reference available for developers wanting to learn how the kernel works and how the major pieces fit together"* * * *"the book contains a number of errors and inconsistencies, and it fails to cover no end of interesting things which have happened in the kernel over the last five years while retaining text which was obsolete even in previous editions." * * * *"the amount of old stuff that leaked through, combined with the things which should have been mentioned but weren't, seems a bit high; some of them should, at least, have been caught in technical review."* He mentioned a lot of errata in that article which might be of use to you. Regards, Raahi

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strange behavior of sk_rmem_alloc
by sugnan prabhu Dec. 29, 2010

Dec. 29, 2010

Hello all, I have written a network driver, address family and a protocol family, when i create a socket in a user space program to my PF and AF, it receives only first 300 packets and i see that all the packets are being received till the function sk_recieve_skb() is called. When i tried searching for the root of the cause, i found that *sk_rcvqueues_full(sk,skb) *returns true after receiving 300 packets, further observing the cause i found that the variable *sk_rmem_alloc* which is being checked in the function in never getting decremented. http://www.pubbs.net/200912/kernel/700-seeing-strange-values-for-tcp-skrmem… <http://www.pubbs.net/200912/kernel/700-seeing-strange-values-for-tcp-skrmem…>In the above link i found that some one had similar problem, and as it says calling *skb_copy_datagram_iovec()* should decrement the *sk_rmem_alloc*, am even doing that. So can some suggest what can be the problem. One more strange thing is *sk_queue_empty(&sk->receive_queue)* start returning true after 300 packet. --------------------------------------------------- Thanking You, Sugnan Prabhu S http://sugnanprabhu.blogspot.com/

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Fwd: Regarding CPU softlockup issue
by Pradeep Kumar Dec. 28, 2010

Dec. 28, 2010

hi all, I got the fallowing soft lockup error "BUG: soft lockup - CPU#0 stuck for 16s! [Playback Thread:9266"] is that 16s is the value of /proc/sys/kernel/softlockup_thresh ?? if yes, can I get rid of that message/panic by setting softlockup_thresh to some value greater that 30 ??? -- Goudagunta Pradeep Kumar,

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Regarding CPU softlockup issue
by Pradeep Kumar Dec. 28, 2010

Dec. 28, 2010

hi all, I got the fallowing soft lockup error "BUG: soft lockup - CPU#0 stuck for 16s! [Playback Thread:9266"] is that 16s is the value of /proc/sys/kernel/softlockup_thresh ?? if yes, can I get rid of that message/panic by setting softlockup_thresh to some value greater that 30 ??? -- Goudagunta Pradeep Kumar,

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Re: final year project
by madhavan raghavan Dec. 28, 2010

Dec. 28, 2010

Hi , I interested in working on Scheduler part of kernel , I searching for a project in Scheduler that can be done as a final year project . Regards Raghavan

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BS Final Project
by Niloofar Javadi Dec. 28, 2010

Dec. 28, 2010

Dear all , I was wondering to find a good topic for my BS final project in linux kernel topics,Does any body have an idea about what to choose and where to start?I have nearly 6 months to complete that. Regards

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recurring problem, booting git-built to black screen with intel GPU
by Robert P. J. Day Dec. 28, 2010

Dec. 28, 2010

this is a copy of something i forwarded to the linux kernel mailing list, and i'd be interested if anyone else would test this and reproduce the problem: ===== start ===== on my ubuntu laptop (gateway NV79), a 2.6.37-rc7+ kernel i just built now boots to a black screen. no text mode, no virtual consoles, nothing. this is probably the best explanation: http://www.oblurb.com/ubuntu-dell-latitude-e6510-intel-gpu-blank-screen.html annoyingly, i'm currently running a 2.6.37-rc5+ hand-rolled kernel that works fine, but this more recent kernel doesn't, and a kernel *earlier* also doesn't work, so this issue seems to come and go. here's another extended conversation on the same topic: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/600453 here's the relevant output from lspci: 00:02.0 VGA compatible controller: Intel Corporation Core Processor Integrated Graphics Controller (rev 12) (prog-if 00 [VGA controller]) Subsystem: Acer Incorporated [ALI] Device 031c Flags: bus master, fast devsel, latency 0, IRQ 41 Memory at d0000000 (64-bit, non-prefetchable) [size=4M] Memory at c0000000 (64-bit, prefetchable) [size=256M] I/O ports at 3050 [size=8] Expansion ROM at <unassigned> [disabled] Capabilities: <access denied> Kernel driver in use: i915 Kernel modules: i915 if i use "nomodeset", i can boot to the command line and no further. i'm open to suggestions. ===== end ===== in short, a while back, building a kernel from the git repo failed to give me a working kernel. suddenly, as of 2.6.37-rc5, it worked fine and it's the kernel i'm running under right now: $ uname -r 2.6.37-rc5+ $ and now, as of 2.6.37-rc7, it's back to being borked. i'd love to have piles of free time to track this down but, before i do that, i'd be interested in having someone else try this and let me know if exactly the same thing happens for them. this is a a gateway NV79 laptop, intel core i3-330m, with intel integrated graphics controller. thoughts? rday p.s. it seems clear that the system doesn't simply hang. even after the screen goes black very early in the boot process, there is ample disk activity showing that the boot is continuing, and i eventually hear the little ubuntu "drum roll" that indicates i'm at the login screen. so it's just the video that's died. -- ======================================================================== Robert P. J. Day Waterloo, Ontario, CANADA http://crashcourse.ca Twitter: http://twitter.com/rpjday LinkedIn: http://ca.linkedin.com/in/rpjday ========================================================================

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Reserving physical memory in Linux
by Asha R Dec. 28, 2010

Dec. 28, 2010

Hi, I want to reserve one range of physical memory say from 0x10000000 of 256MB in Linux. This region is required for DMA functions alone. Please help me understand how we can reserve this in Linux. Can this be done using boot options or any other? Regards, Asha

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