Kernelnewbies Digest, Vol 17, Issue 44

Thu Apr 26 13:40:14 EDT 2012

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 ?

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
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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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