Arnaldo's RamblingsRecently I saw somebody boasting that Linus now uses Fedora and I don’t know why I found it silly. But then when Ingo Molnar even mentioned the name of the package where codiff is available I found that I can be silly too
Since I haven’t blogged about these toys, please take a look at Carsten’s article at OSADL and perhaps at my OLS 2008 paper too.
Work is supposed to take most of your time, right? Survival, mouths to feed, all that stuff… But it can be fun, even if not _directly_ kernel related. Sure, there is life outside the kernel, hey, “kernel”… I keep listening to the head-honchos (heck, I had to use that term, it looks like spanish, the [...]
Finally I found time to convert dwarves to use the more active libdwfl library found in elfutils, thanks to Ulrich Drepper and Roland McGrath we can forget about most of the low level details related to RELA architectures and get the dwarves to work with kernel modules on architectures such as x86_64, where we need [...]
Pahole: Now we can also move bitfields around to combine it with other fields, moving a list of members with the same offset (the definition of a bitfield) to after other members that have holes bigger than the size of the (possibly type demoted) list of members comprising a bitfield, also there is a new [...]
Say a project has this struct: struct cheese { char name[52]; char a; int b; char c; int d; short e; }; And we want to see how the layout looks like more precisely: [acme@filo examples]$ pahole swiss_cheese cheese /* <11b> /home/acme/git/pahole/examples/swiss_cheese.c:3 */ struct cheese { char name[52]; /* 0 52 */ char a; /* [...]
Make sure you have the kernel-debuginfo package installed! rpm -ivh http://oops.ghostprotocols.net:81/acme/dwarves/rpm/libdwarves1-0-9.i386.rpm http://oops.ghostprotocols.net:81/acme/dwarves/rpm/dwarves-0-9.i386.rpm mkdir foo cd foo ln -s /usr/lib/ctracer/Makefile . ln -s /usr/lib/ctracer/ctracer_jprobe.c . make CLASS=sock insmod ctracer.ko # do some networking activity or just move the mouse dmesg # or tail /var/log/messages rmmod ctracer Now to work on kahole, kill a hole, a tool [...]
After all it will be eclipsed by the 6th, and then by the long cherished 7th, the one that will trigger the 1.0 pahole (btw, the 1st dwarf!) release. So, without too much ado, ctracer, the aforementioned current dwarf, is making great inroads into being something useful to more than one person, perhaps, but anyway, [...]
Have to cook the turkey, so this one will be brief, have been working on a new tool, that ultimately will provide what ostra was capable of, ctracer, the new tool generates a kernel module that after built and loaded provides these preliminary results. Now to work on a not so lame relaying module for [...]
Andrew Morton merged the two patches I’ve submitted for saving bytes in struct inode and struct mm_struct, great! I’ve also did some more work on pahole based on ideas by Bernhard Fischer, that also provided a patch fixing the –help command line option. On the DCCP front we’re going thru some growing pains, with CCID3 [...]
