On 01/17/2011 07:01 PM, Amker.Cheng wrote:
Hi, Previously I have run oprofile on linux-mips and have two questions about it. It seems that oprofile does not support callgraph on linux-mips currently, since there is no backtrace function in oprofile kernel module for mips target. Is it possible or easy to support callgraph on mips target? If I am right, it's some kind of difficult to calculate stack frames of interrupted user space programs, at least for O32 ABI.
By default, most MIPS code doesn't use frame pointers. This makes generating an accurate stack trace either very difficult or impossible.
If you compile *all* your user space code with -fno-omit-framepointer, you could write a fairly simple stack walker. Otherwise you have to do code analysis to try to get a stack trace, and that is quite complex, and at in some cases impossible.
Any tips would be appriciated. thanks.
I wrote a userspace o32 stack trace generator once and posted it to java-patches@xxxxxxxxxxxx If you search for it you might find it.
David Daney