Kernelnewbies Digest, Vol 17, Issue 44

Thu Apr 26 23:29:24 EDT 2012

Hi Jeshwanth,

On Thu, Apr 26, 2012 at 11:10 PM, Jeshwanth Kumar N K Jeshu
<jeshkumar555 at gmail.com> wrote:
> Hello guys,
> I am writing a user space code for pwm controller in beaglebone, but the
> drivers are in the form of files, so when I am writing the code I got a
> doubt that, if we keep access the files it may take more processor time so
> any other way is there to access or this is the best way ?

Can you be more clear here. Are you talking about source code?

Arun
>
> On Thu, Apr 26, 2012 at 9:30 PM, <kernelnewbies-request at kernelnewbies.org>
> wrote:
>>
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>> Today's Topics:
>>
>>   1. Re: Profiling my Modules (Daniel Baluta)
>>   2. Re: Linux Driver Project (Bj?rn Mork)
>>   3. Re: Profiling my Modules (Rishi Agrawal)
>>   4. Re: Linux Driver Project (Bj?rn Mork)
>>   5. freelance kernel work (Christopher Harvey)
>>
>>
>> ----------------------------------------------------------------------
>>
>> Message: 1
>> Date: Thu, 26 Apr 2012 15:42:57 +0300
>> From: Daniel Baluta <daniel.baluta at gmail.com>
>> Subject: Re: Profiling my Modules
>> To: Rishi Agrawal <rishi.b.agrawal at gmail.com>
>> Cc: kernelnewbies at kernelnewbies.org
>> Message-ID:
>>
>>  <CAEnQRZCf1zjMAQSe8uuYTr7px6-K51fLpB+vwY3SMkDXimcpxw at mail.gmail.com>
>> Content-Type: text/plain; charset=ISO-8859-1
>>
>> On Thu, Apr 26, 2012 at 10:33 AM, Rishi Agrawal
>> <rishi.b.agrawal at gmail.com> wrote:
>> > Hi All,
>> >
>> > I have a kernel module which has functions which take a lot of time in
>> > execution. I am curious to know how can I profile it, and find out the
>> > functions taking most of the time.
>> >
>> > I saw Oprofile, but it seems that I will have to build the whole kernel,
>> > and
>> > also that it will be difficult to profile my module through it.
>> >
>> > Any trick or tool will do.
>>
>> Hello,
>>
>> Have a look at perf [1].
>>
>> thanks,
>> Daniel.
>>
>> [1] https://perf.wiki.kernel.org/
>>
>>
>>
>> ------------------------------
>>
>> Message: 2
>> Date: Thu, 26 Apr 2012 15:16:59 +0200
>> From: Bj?rn Mork <bjorn at mork.no>
>> Subject: Re: Linux Driver Project
>> To: Rabee Al-Maqabi <rabee.almaqabi at gmail.com>
>> Cc: Javier Martinez Canillas <martinez.javier at gmail.com>,
>>        kernelnewbies at kernelnewbies.org
>> Message-ID: <87fwbqeipg.fsf at nemi.mork.no>
>> Content-Type: text/plain; charset=utf-8
>>
>> Rabee Al-Maqabi <rabee.almaqabi at gmail.com> writes:
>>
>> > Thank you for your reply. Linux Device Drivers is indeed a great book. I
>> > have read it in addition to Understanding the Linux Kernel and I have
>> > experimented with my Linux box. At this point, I would like to have a
>> > real-world experience and write a driver for a piece of hardware not yet
>> > supported.
>>
>> How about a fingerprint scanner?  If you've got a modern laptop then
>> chances are good that you already own such a device.  And it's
>> most likely unsupported.  Some might say that's because it's useless :-)
>>
>> Otherwise I'd recommend looking through your box of unused devices.  No
>> need to go out and buy anything if all you want is to write some
>> driver.
>>
>> Or see
>> http://www.linuxdriverproject.org/foswiki/bin/view/Main/DriversNeeded
>> if you are open to buying some new device for this project.
>>
>> You won't find any datasheets or any other documentation, though...
>> Manufacturers smart enough to provide documentation usually get drivers
>> written for their devices in no time.  But some still hold it to
>> themselves.  Go figure.
>>
>>
>> Bj?rn
>>
>>
>>
>> ------------------------------
>>
>> Message: 3
>> Date: Thu, 26 Apr 2012 19:01:00 +0530
>> From: Rishi Agrawal <rishi.b.agrawal at gmail.com>
>> Subject: Re: Profiling my Modules
>> To: Daniel Baluta <daniel.baluta at gmail.com>
>> Cc: kernelnewbies at kernelnewbies.org
>> Message-ID:
>>
>>  <CADDndfPtRis6CuXJN7D0v=snCJ8b_hS0eW2cQoBekXE3UtyXSw at mail.gmail.com>
>> Content-Type: text/plain; charset="iso-8859-1"
>>
>> Thanks a lot, I will have a look at it and see if it helps.
>>
>> On Thu, Apr 26, 2012 at 6:12 PM, Daniel Baluta
>> <daniel.baluta at gmail.com>wrote:
>>
>> > On Thu, Apr 26, 2012 at 10:33 AM, Rishi Agrawal
>> > <rishi.b.agrawal at gmail.com> wrote:
>> > > Hi All,
>> > >
>> > > I have a kernel module which has functions which take a lot of time in
>> > > execution. I am curious to know how can I profile it, and find out the
>> > > functions taking most of the time.
>> > >
>> > > I saw Oprofile, but it seems that I will have to build the whole
>> > > kernel,
>> > and
>> > > also that it will be difficult to profile my module through it.
>> > >
>> > > Any trick or tool will do.
>> >
>> > Hello,
>> >
>> > Have a look at perf [1].
>> >
>> > thanks,
>> > Daniel.
>> >
>> > [1] https://perf.wiki.kernel.org/
>> >
>>
>>
>>
>> --
>> Regards,
>> Rishi Agrawal
>> -------------- next part --------------
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>>
>> ------------------------------
>>
>> Message: 4
>> Date: Thu, 26 Apr 2012 15:51:10 +0200
>> From: Bj?rn Mork <bjorn at mork.no>
>> Subject: Re: Linux Driver Project
>> To: Rabee Al-Maqabi <rabee.almaqabi at gmail.com>
>> Cc: Javier Martinez Canillas <martinez.javier at gmail.com>,
>>        kernelnewbies at kernelnewbies.org
>> Message-ID: <877gx2eh4h.fsf at nemi.mork.no>
>> Content-Type: text/plain; charset=utf-8
>>
>> Bj?rn Mork <bjorn at mork.no> writes:
>>
>> > How about a fingerprint scanner?  If you've got a modern laptop then
>> > chances are good that you already own such a device.  And it's
>> > most likely unsupported.  Some might say that's because it's useless :-)
>>
>> Sorry, please ignore this.  I should have read
>>
>> http://www.linuxdriverproject.org/foswiki/bin/view/Main/NoLinuxDriverNeeded
>> first.
>>
>>
>> Bj?rn
>>
>>
>>
>> ------------------------------
>>
>> Message: 5
>> Date: Thu, 26 Apr 2012 10:39:41 -0500
>> From: Christopher Harvey <chris at basementcode.com>
>> Subject: freelance kernel work
>> To: <kernelnewbies at kernelnewbies.org>
>> Message-ID: <8acfa9e97f0b3bca53f505c1aca01aed at basementcode.com>
>> Content-Type: text/plain; charset=UTF-8; format=flowed
>>
>> I'm not looking for work, nor do I have any work for others. I'm just
>> curious if there is a central location where freelance kernel
>> developers hang out. I've never seen any email on mailing lists like
>> "I have some hardware and want somebody to write a kernel module for
>> it". I thought that sort of request would have been common.
>>
>>
>>
>> ------------------------------
>>
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>> End of Kernelnewbies Digest, Vol 17, Issue 44
>> *********************************************
>
>
>
>
> --
> Regards
> Jeshwanth Kumar N K
> +91-7411483498
>
>
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