bcc included in RHEL 8.6 doesn't support the kernel_struct_has_field function.

The 4.18.x kernel in RHEL 8.6 did backport the `state` to `__state` rename (upstream:

change was in kernel v5.14+), and now we're in a situation where we can't test for

the existence of this kernel struct member and also can't rely on a kernel version check.

Therefore, let's patch it here for RHEL 8.x only:

diff --git a/src/pmdas/bcc/modules/runqlat.python b/src/pmdas/bcc/modules/runqlat.python

index 1c6c6b4b0..efc30e958 100644

--- a/src/pmdas/bcc/modules/runqlat.python

+++ b/src/pmdas/bcc/modules/runqlat.python

@@ -100,7 +100,7 @@ class PCPBCCModule(PCPBCCBase):

                 if (

                     hasattr(BPF, "kernel_struct_has_field")

                     and BPF.kernel_struct_has_field(b"task_struct", b"__state") == 1

-                ) or self.kernel_version() >= (5, 14, 0):

+                ) or self.kernel_version() >= (4, 18, 0):

                     self.bpf_text = self.bpf_text.replace('STATE_FIELD', '__state')

                 else:

                     self.bpf_text = self.bpf_text.replace('STATE_FIELD', 'state')