* Memory problems in schedule()
@ 2005-06-06 1:01 Vishal Patil
2005-06-06 2:31 ` Jeff Dike
0 siblings, 1 reply; 4+ messages in thread
From: Vishal Patil @ 2005-06-06 1:01 UTC (permalink / raw)
To: linux-kernel
Hi
I am trying to implement a different process scheduling algorithm in linux
kernel 2.4.30. I am doing this as a hobby and am using User Mode Linux
to test my changes. I have the following problems with the implement
1) Whenever I select a process to run using my algorithm the kernel
panics with "Segfault with no mm" basically the "mm" field of the
task_struct that I selected is empty. I don't understand why this
should happen, since I have just added code to select a process and
haven't modified any memory related code in the schedule() function.
2) I am able to run the UMLfied kernel under gdb, however the execution
never halts even though I set several breakpoints. Also these
breakpoints have not been set in interrupt handling code and I have
compiled the code with -g option.
I have been stuck with these problems since a long time and would
appreciate if someone could help me with it.
Thank you all.
- Vishal
--
A dream is just a dream. A goal is a dream with a plan and a deadline.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Memory problems in schedule()
2005-06-06 1:01 Memory problems in schedule() Vishal Patil
@ 2005-06-06 2:31 ` Jeff Dike
2005-06-06 12:24 ` Vishal Patil
0 siblings, 1 reply; 4+ messages in thread
From: Jeff Dike @ 2005-06-06 2:31 UTC (permalink / raw)
To: Vishal Patil; +Cc: linux-kernel
On Sun, Jun 05, 2005 at 09:01:19PM -0400, Vishal Patil wrote:
> 1) Whenever I select a process to run using my algorithm the kernel
> panics with "Segfault with no mm" basically the "mm" field of the
> task_struct that I selected is empty. I don't understand why this
> should happen, since I have just added code to select a process and
> haven't modified any memory related code in the schedule() function.
Start with a backtrace from the panic and debug it from there.
> 2) I am able to run the UMLfied kernel under gdb, however the execution
> never halts even though I set several breakpoints. Also these
> breakpoints have not been set in interrupt handling code and I have
> compiled the code with -g option.
UML and gdb versions? tt or skas mode?
Jeff
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Memory problems in schedule()
2005-06-06 2:31 ` Jeff Dike
@ 2005-06-06 12:24 ` Vishal Patil
2005-06-06 13:44 ` Jeff Dike
0 siblings, 1 reply; 4+ messages in thread
From: Vishal Patil @ 2005-06-06 12:24 UTC (permalink / raw)
To: Jeff Dike; +Cc: linux-kernel
Jeff
Please find the answer to questions below,
On 6/5/05, Jeff Dike <jdike@addtoit.com> wrote:
> On Sun, Jun 05, 2005 at 09:01:19PM -0400, Vishal Patil wrote:
> > 1) Whenever I select a process to run using my algorithm the kernel
> > panics with "Segfault with no mm" basically the "mm" field of the
> > task_struct that I selected is empty. I don't understand why this
> > should happen, since I have just added code to select a process and
> > haven't modified any memory related code in the schedule() function.
>
> Start with a backtrace from the panic and debug it from there.
>
> > 2) I am able to run the UMLfied kernel under gdb, however the execution
> > never halts even though I set several breakpoints. Also these
> > breakpoints have not been set in interrupt handling code and I have
> > compiled the code with -g option.
>
> UML and gdb versions? tt or skas mode?
GNU gdb Red Hat Linux (6.1post-1.20040607.41rh)
uml-patch-2.4.27-1
skas mode.
Thank you.
> Jeff
>
--
A dream is just a dream. A goal is a dream with a plan and a deadline.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Memory problems in schedule()
2005-06-06 12:24 ` Vishal Patil
@ 2005-06-06 13:44 ` Jeff Dike
0 siblings, 0 replies; 4+ messages in thread
From: Jeff Dike @ 2005-06-06 13:44 UTC (permalink / raw)
To: Vishal Patil; +Cc: linux-kernel
On Mon, Jun 06, 2005 at 08:24:39AM -0400, Vishal Patil wrote:
> GNU gdb Red Hat Linux (6.1post-1.20040607.41rh)
> uml-patch-2.4.27-1
> skas mode.
Disable CONFIG_MODE_TT. gdb seems confused by the exec that tt mode does
early on.
Jeff
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2005-06-06 13:49 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2005-06-06 1:01 Memory problems in schedule() Vishal Patil
2005-06-06 2:31 ` Jeff Dike
2005-06-06 12:24 ` Vishal Patil
2005-06-06 13:44 ` Jeff Dike
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