Hi,
I am trying a simple char driver and for debug purposes I have added
lot of printks
in my module. The module is rather heavily being used by my test app which does
hundreds of open/read/write calls. The driver just copies and prints
incoming/outgoing
buffers.
I see a lot of garbled output in /var/log/messages
E.g.
Oct 27 00:18:47 ubuntu-vm kernel: [ 4903.382917] returned buf "Hello"
Oct 27 00:18:47 ubuntu-vm kernel: [ 4903.382925] returned buf "Hello"
Oct 27 00:18:47 ubuntu-vm kernel: [ 4903.383033] returned buf "Hello"
reeeeeeeeeexeeeeeeexteeeexeeeeeeeeeeeeeeeeeeeeeeeeeeeeexeeeeeeeeeeeeeeeeeexeeeeeeeeeexteexeeeeeeeeexeeeeeeeeeeeeeeeeeeeeeeexeeeeeeeeeeeexeeeeeeeeeeeexeeeeeeeeeeeeeeeeeeeeexeeeeeeeeeeeeeeeeeeexeeeeeeeeeexteeeeeeeeeeeeeeexeeeext
for 8902 Hello
Oct 27 00:18:47 ubuntu-vm kernel: [ d
Oct 27 00:18:47 ubuntu-vm kernel: dddddddd
Oct 27 00:18:47 ubuntu-vm kernel:
ddddddddn3eexeeeeeeeeeeeeeeeexeeeeeeeeeeeeexeeeeexteeeeeeexeeeeeeeeeeeeeeeeeeeeeeeeeeexeeeeeeeeeexeeeeeeeeeeexeeeeeeeeeeeeexeeeeeeeeeeeeeexeeeeeeeeeexeeeeexeeeeeeeeeeeeeeeeeeeeeeexeeeeeeeeeeeeeeeeeeeeexeeeeeeeeeexeeeeeeeeeeeeeeeeexeeeeeeeext
for 8903 Hello
My loglevel is KERN_INFO, my understanding was a multiline printk
might cause garbled output
on SMPs but a single line printk is always protected using a semaphore.
-Leo.