Hello again, while playing with l4 I got couple of (easy) questions. 1. Can DOpE write a log anywhere on filesystem? 2. Where can I see how much memory I can assign to vmlinuz (how much memory uses DOpE and L4)? 3. What are those 4 slide bars by the linux window in DOpE? 4. How can I run more that one Linux process? 5. Can I use pistachio in place of fiasco? If so, how? 6. How do I halt L4 and DOpE? Hope it's not too much to answer. ratko
Hello Ratko, if you are interested in dynamically starting and stopping applications while running DOpE, you should take a look at the 'run' utility that comes with the loader-examples. Even though this program is a console program, you can use it with DOpE by starting the proxygon server (package proxygon), which implements the console service as DOpE application. By using 'run', you can start and stop programs and dump information about the used dataspaces in the system. This might be a good starting point. For properly killing applications, the event server must be running and you need to specify the '--events' switch for 'dm_phys', 'l4dope', 'simple_ts', and 'names'.
3. What are those 4 slide bars by the linux window in DOpE?
These bars visualize the drawing activity (bus load) of DOpE's simple built-in real-time scheduler. In the past, we used it for demonstrating the real-time properties of DOpE. For normal use, these bars are quite meaningless. However, some of our students liked the 'heartbeat' very much, so I left the load display enabled by default.
6. How do I halt L4 and DOpE?
There is no graceful system shutdown implemented. Usually, we start DOpE via static boot-time GRUB configuration and halt it by rebooting the machine. Regards Norman Feske
Norman Feske said:
6. How do I halt L4 and DOpE?
There is no graceful system shutdown implemented. Usually, we start DOpE via static boot-time GRUB configuration and halt it by rebooting the machine.
as adam has said that DOpE does not touch filesystem, rebooting seems ok. (and if i halt linux application i can hear hard drive stop spinning.) thx, ratko
On Mon Oct 09, 2006 at 16:15:20 +0200, Ratko Rudiè wrote:
1. Can DOpE write a log anywhere on filesystem?
What sort of log? DOpE doesn't know anything about a filesystem. All it does is printing some status messages about itself to the log system, which usually goes out via the serial line.
2. Where can I see how much memory I can assign to vmlinuz (how much memory uses DOpE and L4)?
L4Linux can be given the 'mem=xx' option in the loader config file, like in native Linux. With 'L4', do you mean the kernel? The amount of memory taken by the kernel is configured in the kernel itself and is usually some percent of the system memory up to some maximum. Currently it's something around 6%, iirc.
4. How can I run more that one Linux process?
Easily. Norman already mentioned the 'run' utility. Just start L4Linux another time. You should make sure that the second L4Linux is not touching any hardware the first one is already using, or someone else. Switching off PCI in L4Linux is a good start.
5. Can I use pistachio in place of fiasco? If so, how?
Not really. Pistachio and Fiasco implement different APIs so that software that runs on one kernel does not run on the other and vice versa.
6. How do I halt L4 and DOpE?
This is only relevant if one has volatile data somewhere. E.g. you should make sure to unmount/mount-ro any filesysstems in L4Linux. Besides that just power off or reset. Adam -- Adam adam@os.inf.tu-dresden.de Lackorzynski http://os.inf.tu-dresden.de/~adam/
Adam Lackorzynski said:
2. Where can I see how much memory I can assign to vmlinuz (how much memory uses DOpE and L4)?
L4Linux can be given the 'mem=xx' option in the loader config file, like in native Linux. With 'L4', do you mean the kernel? The amount of memory taken by the kernel is configured in the kernel itself and is usually some percent of the system memory up to some maximum. Currently it's something around 6%, iirc.
yes, I know about mem=xx. What i dont know is: what is maximum memory left for vmlinuz to use. for exmple: i have 128mb of memory in PC. L4 uses: Xmb vmlinuz can use 128mb - Xmb = Ymb I tried giving "mem=64" option but (i think DOpE) says it cannot assign 64mb to vmlinux. option "mem=50" worked. I don't think it's just a "try and see" method, there must be some other way.
4. How can I run more that one Linux process?
Easily. Norman already mentioned the 'run' utility. Just start L4Linux another time. You should make sure that the second L4Linux is not touching any hardware the first one is already using, or someone else. Switching off PCI in L4Linux is a good start.
So new Linux needs another root, swap... seems logical. ratko
On Tue Oct 10, 2006 at 09:03:30 +0200, ratko wrote:
Adam Lackorzynski said:
2. Where can I see how much memory I can assign to vmlinuz (how much memory uses DOpE and L4)?
L4Linux can be given the 'mem=xx' option in the loader config file, like in native Linux. With 'L4', do you mean the kernel? The amount of memory taken by the kernel is configured in the kernel itself and is usually some percent of the system memory up to some maximum. Currently it's something around 6%, iirc.
yes, I know about mem=xx. What i dont know is: what is maximum memory left for vmlinuz to use.
for exmple: i have 128mb of memory in PC. L4 uses: Xmb vmlinuz can use 128mb - Xmb = Ymb
I tried giving "mem=64" option but (i think DOpE) says it cannot assign 64mb to vmlinux. option "mem=50" worked. I don't think it's just a "try and see" method, there must be some other way.
DOpE is 'just' a windowing system, the log messages come from the log server. In your case dm_phys, the memory server, is saying that the requested allocation cannot be fulfilled as there not enough memory with the requested attributes left. dm_phys is also the one to query for remaining memory. When using l4con the free memory of dm_phys is displayed in the status bar. Otherwise one could query it with some program.
4. How can I run more that one Linux process?
Easily. Norman already mentioned the 'run' utility. Just start L4Linux another time. You should make sure that the second L4Linux is not touching any hardware the first one is already using, or someone else. Switching off PCI in L4Linux is a good start.
So new Linux needs another root, swap... seems logical.
Yes. A RAMdisk is quite handy in this case. More advanced setups could involve ore, our network switch, by e.g. NFS mounting filesystems from a specific L4Linux instance. There are also other ways possible. Adam -- Adam adam@os.inf.tu-dresden.de Lackorzynski http://os.inf.tu-dresden.de/~adam/
participants (4)
-
Adam Lackorzynski -
Norman Feske -
ratko -
Ratko Rudič