Showing posts from June, 2011

Adding header to kernel-headers rpm package

I wanted to distribute the header files placed on /usr/include/linux by a custom kernel-headers package. Isn't it just put the file at /home/peter/rpmbuild/BUILD/ ? No! This is only 50% of the work. The other 50% consists of adding a line to the file: /home/peter/rpmbuild/BUILD/ The line looks like: header-y += pst_syscalls.h And voila! Now it is done! The expected result is: [peter@KDPeter ~]$ rpm -qf /usr/include/linux/pst_syscalls.h kernel-headers-

How to tell rpmbuild the number of simultaneous jobs? (make -j)

On Fedora 15, setting the environment variable RPM_BUILD_NCPUS allows you to configure the number up to 16 simultaneous jobs. For example to set the number of simultaneous jobs to 12, so rpmbuild will call make -j12: $ export RPM_BUILD_NCPUS=12 But if you need more than 16 simultaneous jobs, you will need to edit ~/.rpmmacros file. To allow numbers greater than 16, I've modified this file to: [peter@notepeter ~]$ cat .rpmmacros %_topdir %(echo $HOME)/rpmbuild %_smp_mflags %( \ [ -z "$RPM_BUILD_NCPUS" ] \\\ && RPM_BUILD_NCPUS="`/usr/bin/getconf _NPROCESSORS_ONLN`"; \\\ if [ "$RPM_BUILD_NCPUS" -gt 16 ]; then \\\ echo "-j $RPM_BUILD_NCPUS "; \\\ elif [ "$RPM_BUILD_NCPUS" -gt 3 ]; then \\\ echo "-j$RPM_BUILD_NCPUS"; \\\ else \\\ echo "-j3"; \\\ fi ) %__arch_install_post \ [ "%{buildarch}" = "noarch" ] || QA_CHECK_RPATHS=1 ; \ case "${QA_CHECK_RPATHS:-}" in

distcc is my friend!

Last month I spent some time on distcc trying to reduce Kernel build time. The original post is here . I had no success that time. I've tried it again. Now it was a true success. :-) distcc reduced the build time of Fedora Kernel ~ 53% when using 3 PCs instead of one. From 25m5.938s to 11m52.751s. Details: With distcc: [peter@notepeter SPECS]$ cd /home/peter/distcc/ [peter@notepeter distcc]$ ls -la total 8 drwxrwxr-x 2 peter peter 4096 Jun 27 20:33 . drwx------. 49 peter peter 4096 Jun 27 20:48 .. lrwxrwxrwx 1 peter peter 15 Jun 27 20:33 c++ -> /usr/bin/distcc lrwxrwxrwx 1 peter peter 15 Jun 27 20:33 cc -> /usr/bin/distcc lrwxrwxrwx 1 peter peter 15 Jun 27 20:33 g++ -> /usr/bin/distcc lrwxrwxrwx 1 peter peter 15 Jun 27 20:33 gcc -> /usr/bin/distcc [peter@notepeter distcc]$ cd - [peter@notepeter SPECS]$ rpmbuild --clean kernel.spec [peter@notepeter SPECS]$ export PATH=/home/peter/distcc/:$PATH [peter@notepeter SPECS]$ export DISTCC_

It works!

I've just successfully run my code into Kernel # This shows that my kernel_thread is running [peter@KDPeter ~]$ ps -ef |grep pst root 1373 2 0 21:09 ? 00:00:00 [pst_daemon2] I wasn't being able to invoke my system calls from user land because I was using the obsolete _syscall1 macro instead of using syscall(). The original and old documentation that describes system calls and kernel_thread is here . There will be new documentation soon... :-)

Peter's "content" contribution 1

It is not Kernel code yet, but I liked it. I added some lines to Fedora Wiki on Building Custom Kernel: As I do not know about how many time this content will be available on the site, I took a screenshot of it. :-)