Re: How to properly import the configuration of the Buster kernel into own development ?

["Thomas Schmitt" <scdbackup@gmx.net>]

Hi,

so i went back to the original configuration for exactly one kernel build
and installation. Full make lasts 70 minutes, a development cycle lasts
more than 3 minutes, even after running
  scripts/config --disable DEBUG_INFO
It builds our universe and a few alternative ones too.

So for the time of hacking, i am back to the sparse configuration from
"make localmodconfig" (plus some manual widening).
A build lasts about 1 minute, if no widely used header files got changed.

(Times are measured without make option -j, because of the current
 environment heat.)


I wrote:
> > > -rwxr-xr-x 1 root root 35424 Aug 26  1904 /mnt/iso/victim
> >   -rwxr-xr-x 1 root root 35424 Oct  1  2040 /mnt/iso/victim

songbird wrote:
>   always interesting!  :)

I have more:

- The classic CD read-ahead bug (nearly as old as Linux is):
  CD burned with write type TAO get reported by about 80 percent of all
  drives with a readable size that is 1 or 2 blocks too large. Linux is
  credulent and courageous enough to then produce i/o errors at the attempt
  to read the last blocks ahead of the request of the filesystem.

- Burning more than one DVD or BD simultaneously is darn slow.

- Automatic CD/DVD/BD tray loading on read attempt happens, but the attempt
  fails immediately with a "no medium" error.
    dd if=/dev/sr0 of=/dev/null
  Retry succeeds after the drive had time to examine the medium.

- Blank CD, DVD, or BD are reported by lsblk with a size 2048 bytes.
  But readable are 0 bytes.

- An empty drive tray gets reported by lsblk with the size of the previously
  inserted medium. Default at boot time is 1024M.

- mount -t iso9660 option -o session=N does not work for DVD and BD.
  (Have dust masks ready when entering this part of the kernel's basement.)

- Filenames of length 254 or 255 in mounted ISO 9660 (with Rock Ridge) get
  truncated to some much shorter length. (Permissible are 255 bytes of name
  length. Truncation should aim for that length.)

- Burn programs have no means to tell the kernel that readable size or
  content of CD, DVD, or BD have changed. (One has to eject and re-load.)

Now i run out of bugs and wishes. Thus i will have to begin exploring
life with an upstream development kernel.


Have a nice day :)

Thomas