[Crash-utility] [PATCH] runq: make tasks in throttled cfs_rqs/rt_rqs displayed

[Dave Anderson]

----- Original Message -----

> And to follow up, I'm still running tests (and will do so overnight) on your latest
> patch, but I immediately see this on any 2.6.30, 2.6.31 or 2.6.32 kernel, and on
> some 2.6.36 and 2.6.38 kernels, where "runq -g" fails like this:
> 
>   crash> runq -g
>   runq: invalid kernel virtual address: 0  type: "dentry"
>   crash>

The error above is pretty persistent on all kernels from 2.6.27 to 2.6.38,
where you can get a legitimate cgroup that has no dentry:

+static void
+get_task_group_name(ulong group, char **group_name)
+{
+       ulong cgroup, dentry, name;
+       char *dentry_buf, *tmp;
+       int len;
+
+       readmem(group + OFFSET(task_group_css) + OFFSET(cgroup_subsys_state_cgroup),
+               KVADDR, &cgroup, sizeof(ulong),
+               "task_group css cgroup", FAULT_ON_ERROR);
+       if (cgroup == 0)
+               return;
+
+       readmem(cgroup + OFFSET(cgroup_dentry), KVADDR, &dentry, sizeof(ulong),
+               "cgroup dentry", FAULT_ON_ERROR);
+
+       dentry_buf = GETBUF(SIZE(dentry));
+       readmem(dentry, KVADDR, dentry_buf, SIZE(dentry),
+               "dentry", FAULT_ON_ERROR);

Dave