Red Hat Bugzilla – Bug 503778
memory leak in function graph tracer
Last modified: 2016-05-22 19:28:14 EDT
Description of problem:
Every time you enable the function graph tracer, it assigns a new ret_stack to the idle tasks. But this does not test to see if it was already allocated. Thus, every time the function graph tracer is enabled we allocate a new ret_stack for idle tasks.
This is a memory leak, and also can cause a crash because it is possible that we replace the ret_stack of the idle task while it is using it.
Is this still a bug?
Not for 2.6.31 kernels, but I don't know about anything earlier.
Please take a look at the 188.8.131.52 kernel tree (grab luis' latest git tree) and see if it looks like we have a problem in ftrace there.
Not relevant to v1 kernel (no function graph tracer there); fixed in .31 kernels with git commit: 179c498ae2998461fe436437a74dc29036fc7dcc
included in 2.6.33 kernel