Compile kernel for various times and problem of too long time consuming

Compile kernel for various times and problem of too long time consuming

[Amirali Shambayati]

Hi all,
Since I want to evaluate performance improvements by changing just one
file in kernel(noop-iosched) and compiling kernel is too much
time-consuming, I want to know that if I compile kernel for more than
one time, does it take similar time to first time?

I use following commands. If I don't use "make-kpkg clean" for next
times, does it just compile the files which have been modified or it
compile whole kernel package again?

make-kpkg clean
fakeroot make-kpkg --initrd --append-to-version=-some-string-here
kernel-image kernel-headers


Thanks for your help in advance,

--
Amirali Shambayati
Bachelor Student
Computer Engineering Department
Sharif University of Technology
Tehran, Iran

Re: Compile kernel for various times and problem of too long time consuming

[Amirali Shambayati]

It is very urgent for me to find my question's answer soon.
Your help is appreciated:)

On Sun, Aug 7, 2011 at 9:39 PM, Amirali Shambayati
<amirali.shambayati@gmail.com> wrote:
> Hi all,
> Since I want to evaluate performance improvements by changing just one
> file in kernel(noop-iosched) and compiling kernel is too much
> time-consuming, I want to know that if I compile kernel for more than
> one time, does it take similar time to first time?
>
> I use following commands. If I don't use "make-kpkg clean" for next
> times, does it just compile the files which have been modified or it
> compile whole kernel package again?
>
> make-kpkg clean
> fakeroot make-kpkg --initrd --append-to-version=-some-string-here
> kernel-image kernel-headers
>
>
> Thanks for your help in advance,
>
> --
> Amirali Shambayati
> Bachelor Student
> Computer Engineering Department
> Sharif University of Technology
> Tehran, Iran
>



-- 
Amirali Shambayati
Bachelor Student
Computer Engineering Department
Sharif University of Technology
Tehran, Iran

Re: Compile kernel for various times and problem of too long time consuming

[Randy Dunlap]

On Sun, 7 Aug 2011 21:39:12 +0430 Amirali Shambayati wrote:

> Hi all,
> Since I want to evaluate performance improvements by changing just one
> file in kernel(noop-iosched) and compiling kernel is too much
> time-consuming, I want to know that if I compile kernel for more than
> one time, does it take similar time to first time?
> 
> I use following commands. If I don't use "make-kpkg clean" for next
> times, does it just compile the files which have been modified or it
> compile whole kernel package again?
> 
> make-kpkg clean
> fakeroot make-kpkg --initrd --append-to-version=-some-string-here
> kernel-image kernel-headers

Since I never use make-kpkg, I can only tell you that when I modified
block/noop-iosched.c and rebuilt the kernel, here is what was rebuilt:

  GEN     /lnx/src/NEXT/linux-next-20110805/X32/Makefile
  CHK     include/linux/version.h
  Using /lnx/src/NEXT/linux-next-20110805 as source for kernel
  CHK     include/generated/utsrelease.h
  CALL    /lnx/src/NEXT/linux-next-20110805/scripts/checksyscalls.sh
  CHK     include/generated/compile.h
  CHK     kernel/config_data.h
  CC      block/noop-iosched.o
  LD      block/built-in.o
  LD      vmlinux.o
  MODPOST vmlinux.o
  GEN     .version
  CHK     include/generated/compile.h
  UPD     include/generated/compile.h
  CC      init/version.o
  LD      init/built-in.o
  LD      .tmp_vmlinux1
  KSYM    .tmp_kallsyms1.S
  AS      .tmp_kallsyms1.o
  LD      .tmp_vmlinux2
  KSYM    .tmp_kallsyms2.S
  AS      .tmp_kallsyms2.o
  LD      vmlinux
  SYSMAP  System.map
  SYSMAP  .tmp_System.map
  Building modules, stage 2.
  VOFFSET arch/x86/boot/voffset.h
  CC      arch/x86/boot/version.o
  OBJCOPY arch/x86/boot/compressed/vmlinux.bin
  LZMA    arch/x86/boot/compressed/vmlinux.bin.lzma
  MODPOST 575 modules
  MKPIGGY arch/x86/boot/compressed/piggy.S
  AS      arch/x86/boot/compressed/piggy.o
  LD      arch/x86/boot/compressed/vmlinux
  ZOFFSET arch/x86/boot/zoffset.h
  OBJCOPY arch/x86/boot/vmlinux.bin
  AS      arch/x86/boot/header.o
  LD      arch/x86/boot/setup.elf
  OBJCOPY arch/x86/boot/setup.bin
  BUILD   arch/x86/boot/bzImage
Setup is 14972 bytes (padded to 15360 bytes).
System is 1287 kB
CRC 64ecf4d
Kernel: arch/x86/boot/bzImage is ready  (#18)


so it's a minimal rebuild, not a full kernel rebuild.

---
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***

Re: Compile kernel for various times and problem of too long time consuming

[Amirali Shambayati]

Would you say how you rebuild kernel?

On Sun, Aug 7, 2011 at 10:34 PM, Randy Dunlap <rdunlap@xenotime.net> wrote:
> On Sun, 7 Aug 2011 21:39:12 +0430 Amirali Shambayati wrote:
>
>> Hi all,
>> Since I want to evaluate performance improvements by changing just one
>> file in kernel(noop-iosched) and compiling kernel is too much
>> time-consuming, I want to know that if I compile kernel for more than
>> one time, does it take similar time to first time?
>>
>> I use following commands. If I don't use "make-kpkg clean" for next
>> times, does it just compile the files which have been modified or it
>> compile whole kernel package again?
>>
>> make-kpkg clean
>> fakeroot make-kpkg --initrd --append-to-version=-some-string-here
>> kernel-image kernel-headers
>
> Since I never use make-kpkg, I can only tell you that when I modified
> block/noop-iosched.c and rebuilt the kernel, here is what was rebuilt:
>
>  GEN     /lnx/src/NEXT/linux-next-20110805/X32/Makefile
>  CHK     include/linux/version.h
>  Using /lnx/src/NEXT/linux-next-20110805 as source for kernel
>  CHK     include/generated/utsrelease.h
>  CALL    /lnx/src/NEXT/linux-next-20110805/scripts/checksyscalls.sh
>  CHK     include/generated/compile.h
>  CHK     kernel/config_data.h
>  CC      block/noop-iosched.o
>  LD      block/built-in.o
>  LD      vmlinux.o
>  MODPOST vmlinux.o
>  GEN     .version
>  CHK     include/generated/compile.h
>  UPD     include/generated/compile.h
>  CC      init/version.o
>  LD      init/built-in.o
>  LD      .tmp_vmlinux1
>  KSYM    .tmp_kallsyms1.S
>  AS      .tmp_kallsyms1.o
>  LD      .tmp_vmlinux2
>  KSYM    .tmp_kallsyms2.S
>  AS      .tmp_kallsyms2.o
>  LD      vmlinux
>  SYSMAP  System.map
>  SYSMAP  .tmp_System.map
>  Building modules, stage 2.
>  VOFFSET arch/x86/boot/voffset.h
>  CC      arch/x86/boot/version.o
>  OBJCOPY arch/x86/boot/compressed/vmlinux.bin
>  LZMA    arch/x86/boot/compressed/vmlinux.bin.lzma
>  MODPOST 575 modules
>  MKPIGGY arch/x86/boot/compressed/piggy.S
>  AS      arch/x86/boot/compressed/piggy.o
>  LD      arch/x86/boot/compressed/vmlinux
>  ZOFFSET arch/x86/boot/zoffset.h
>  OBJCOPY arch/x86/boot/vmlinux.bin
>  AS      arch/x86/boot/header.o
>  LD      arch/x86/boot/setup.elf
>  OBJCOPY arch/x86/boot/setup.bin
>  BUILD   arch/x86/boot/bzImage
> Setup is 14972 bytes (padded to 15360 bytes).
> System is 1287 kB
> CRC 64ecf4d
> Kernel: arch/x86/boot/bzImage is ready  (#18)
>
>
> so it's a minimal rebuild, not a full kernel rebuild.
>
> ---
> ~Randy
> *** Remember to use Documentation/SubmitChecklist when testing your code ***
>



-- 
Amirali Shambayati
Bachelor Student
Computer Engineering Department
Sharif University of Technology
Tehran, Iran

Re: Compile kernel for various times and problem of too long time consuming

[Stratos Psomadakis]

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On 08/07/2011 10:48 PM, Amirali Shambayati wrote:
> Would you say how you rebuild kernel?
>
> On Sun, Aug 7, 2011 at 10:34 PM, Randy Dunlap <rdunlap@xenotime.net> wrote:
>> On Sun, 7 Aug 2011 21:39:12 +0430 Amirali Shambayati wrote:
>>
>>> Hi all,
>>> Since I want to evaluate performance improvements by changing just one
>>> file in kernel(noop-iosched) and compiling kernel is too much
>>> time-consuming, I want to know that if I compile kernel for more than
>>> one time, does it take similar time to first time?
>>>
>>> I use following commands. If I don't use "make-kpkg clean" for next
>>> times, does it just compile the files which have been modified or it
>>> compile whole kernel package again?
>>>
>>> make-kpkg clean
>>> fakeroot make-kpkg --initrd --append-to-version=-some-string-here
>>> kernel-image kernel-headers
>> Since I never use make-kpkg, I can only tell you that when I modified
>> block/noop-iosched.c and rebuilt the kernel, here is what was rebuilt:
>>
>>  GEN     /lnx/src/NEXT/linux-next-20110805/X32/Makefile
>>  CHK     include/linux/version.h
>>  Using /lnx/src/NEXT/linux-next-20110805 as source for kernel
>>  CHK     include/generated/utsrelease.h
>>  CALL    /lnx/src/NEXT/linux-next-20110805/scripts/checksyscalls.sh
>>  CHK     include/generated/compile.h
>>  CHK     kernel/config_data.h
>>  CC      block/noop-iosched.o
>>  LD      block/built-in.o
>>  LD      vmlinux.o
>>  MODPOST vmlinux.o
>>  GEN     .version
>>  CHK     include/generated/compile.h
>>  UPD     include/generated/compile.h
>>  CC      init/version.o
>>  LD      init/built-in.o
>>  LD      .tmp_vmlinux1
>>  KSYM    .tmp_kallsyms1.S
>>  AS      .tmp_kallsyms1.o
>>  LD      .tmp_vmlinux2
>>  KSYM    .tmp_kallsyms2.S
>>  AS      .tmp_kallsyms2.o
>>  LD      vmlinux
>>  SYSMAP  System.map
>>  SYSMAP  .tmp_System.map
>>  Building modules, stage 2.
>>  VOFFSET arch/x86/boot/voffset.h
>>  CC      arch/x86/boot/version.o
>>  OBJCOPY arch/x86/boot/compressed/vmlinux.bin
>>  LZMA    arch/x86/boot/compressed/vmlinux.bin.lzma
>>  MODPOST 575 modules
>>  MKPIGGY arch/x86/boot/compressed/piggy.S
>>  AS      arch/x86/boot/compressed/piggy.o
>>  LD      arch/x86/boot/compressed/vmlinux
>>  ZOFFSET arch/x86/boot/zoffset.h
>>  OBJCOPY arch/x86/boot/vmlinux.bin
>>  AS      arch/x86/boot/header.o
>>  LD      arch/x86/boot/setup.elf
>>  OBJCOPY arch/x86/boot/setup.bin
>>  BUILD   arch/x86/boot/bzImage
>> Setup is 14972 bytes (padded to 15360 bytes).
>> System is 1287 kB
>> CRC 64ecf4d
>> Kernel: arch/x86/boot/bzImage is ready  (#18)
>>
>>
>> so it's a minimal rebuild, not a full kernel rebuild.
>>
>> ---
>> ~Randy
>> *** Remember to use Documentation/SubmitChecklist when testing your code ***
>>
just run a make at the toplevel kernel sources directory...if you change
just one file, make won't rebuild everything, just what it needs to be
rebuilt and 'relinked'...

you're rebuilding the whole kernel every time, because you're running
make-pkg clean, which I think runs make clean and cleans every object
file you've built so far...

-- 
Stratos Psomadakis
<psomas@gentoo.org>



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Re: Compile kernel for various times and problem of too long time consuming

[Randy Dunlap]

On Mon, 8 Aug 2011 00:18:04 +0430 Amirali Shambayati wrote:

> Would you say how you rebuild kernel?

Sure, it's just a 'make' command:

$ make -j4 ARCH=i386 O=X32 all


> On Sun, Aug 7, 2011 at 10:34 PM, Randy Dunlap <rdunlap@xenotime.net> wrote:
> > On Sun, 7 Aug 2011 21:39:12 +0430 Amirali Shambayati wrote:
> >
> >> Hi all,
> >> Since I want to evaluate performance improvements by changing just one
> >> file in kernel(noop-iosched) and compiling kernel is too much
> >> time-consuming, I want to know that if I compile kernel for more than
> >> one time, does it take similar time to first time?
> >>
> >> I use following commands. If I don't use "make-kpkg clean" for next
> >> times, does it just compile the files which have been modified or it
> >> compile whole kernel package again?
> >>
> >> make-kpkg clean
> >> fakeroot make-kpkg --initrd --append-to-version=-some-string-here
> >> kernel-image kernel-headers
> >
> > Since I never use make-kpkg, I can only tell you that when I modified
> > block/noop-iosched.c and rebuilt the kernel, here is what was rebuilt:
> >
> >  GEN     /lnx/src/NEXT/linux-next-20110805/X32/Makefile
> >  CHK     include/linux/version.h
> >  Using /lnx/src/NEXT/linux-next-20110805 as source for kernel
> >  CHK     include/generated/utsrelease.h
> >  CALL    /lnx/src/NEXT/linux-next-20110805/scripts/checksyscalls.sh
> >  CHK     include/generated/compile.h
> >  CHK     kernel/config_data.h
> >  CC      block/noop-iosched.o
> >  LD      block/built-in.o
> >  LD      vmlinux.o
> >  MODPOST vmlinux.o
> >  GEN     .version
> >  CHK     include/generated/compile.h
> >  UPD     include/generated/compile.h
> >  CC      init/version.o
> >  LD      init/built-in.o
> >  LD      .tmp_vmlinux1
> >  KSYM    .tmp_kallsyms1.S
> >  AS      .tmp_kallsyms1.o
> >  LD      .tmp_vmlinux2
> >  KSYM    .tmp_kallsyms2.S
> >  AS      .tmp_kallsyms2.o
> >  LD      vmlinux
> >  SYSMAP  System.map
> >  SYSMAP  .tmp_System.map
> >  Building modules, stage 2.
> >  VOFFSET arch/x86/boot/voffset.h
> >  CC      arch/x86/boot/version.o
> >  OBJCOPY arch/x86/boot/compressed/vmlinux.bin
> >  LZMA    arch/x86/boot/compressed/vmlinux.bin.lzma
> >  MODPOST 575 modules
> >  MKPIGGY arch/x86/boot/compressed/piggy.S
> >  AS      arch/x86/boot/compressed/piggy.o
> >  LD      arch/x86/boot/compressed/vmlinux
> >  ZOFFSET arch/x86/boot/zoffset.h
> >  OBJCOPY arch/x86/boot/vmlinux.bin
> >  AS      arch/x86/boot/header.o
> >  LD      arch/x86/boot/setup.elf
> >  OBJCOPY arch/x86/boot/setup.bin
> >  BUILD   arch/x86/boot/bzImage
> > Setup is 14972 bytes (padded to 15360 bytes).
> > System is 1287 kB
> > CRC 64ecf4d
> > Kernel: arch/x86/boot/bzImage is ready  (#18)
> >
> >
> > so it's a minimal rebuild, not a full kernel rebuild.



---
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***

Re: Compile kernel for various times and problem of too long time consuming

[WANG Cong]

On Sun, 07 Aug 2011 21:39:12 +0430, Amirali Shambayati wrote:

> Hi all,
> Since I want to evaluate performance improvements by changing just one
> file in kernel(noop-iosched) and compiling kernel is too much
> time-consuming, I want to know that if I compile kernel for more than
> one time, does it take similar time to first time?
> 
> I use following commands. If I don't use "make-kpkg clean" for next
> times, does it just compile the files which have been modified or it
> compile whole kernel package again?
> 
> make-kpkg clean
> fakeroot make-kpkg --initrd --append-to-version=-some-string-here
> kernel-image kernel-headers

Don't run 'make-kpkg clean', and try to use ccache,
make CC='ccache gcc'

Re: Compile kernel for various times and problem of too long time consuming

[Javier Martinez Canillas]

On Sun, Aug 7, 2011 at 7:09 PM, Amirali Shambayati
<amirali.shambayati@gmail.com> wrote:
> Hi all,
> Since I want to evaluate performance improvements by changing just one
> file in kernel(noop-iosched) and compiling kernel is too much
> time-consuming, I want to know that if I compile kernel for more than
> one time, does it take similar time to first time?
>
> I use following commands. If I don't use "make-kpkg clean" for next
> times, does it just compile the files which have been modified or it
> compile whole kernel package again?
>
> make-kpkg clean
> fakeroot make-kpkg --initrd --append-to-version=-some-string-here
> kernel-image kernel-headers
>
>
> Thanks for your help in advance,
>
> --
> Amirali Shambayati
> Bachelor Student
> Computer Engineering Department
> Sharif University of Technology
> Tehran, Iran
>
> _______________________________________________
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>

Some time ago I wrote a blog entry about "Speeding up Linux kernel
compilation", hope it helps

http://martinezjavier.blogspot.com/2011/03/speeding-up-linux-kernel-compilation.html

Best regards

-- 
Javier Martínez Canillas
(+34) 682 39 81 69