X-Git-Url: https://git.kernel.dk/?a=blobdiff_plain;f=Documentation%2Fgdb-kernel-debugging.txt;h=4ab7d43d07544f7a22b35e49f9eb691eb3e9204d;hb=4b2427605e5325eafb5cfc2698f517db68e41075;hp=7050ce8794b9a4b3dd93b76dd9e2a6d708b468ee;hpb=cb8a4deaf9b2778653c4391d8ccb24c5ab159f9d;p=linux-2.6-block.git

diff --git a/Documentation/gdb-kernel-debugging.txt b/Documentation/gdb-kernel-debugging.txt
index 7050ce8794b9..4ab7d43d0754 100644
--- a/Documentation/gdb-kernel-debugging.txt
+++ b/Documentation/gdb-kernel-debugging.txt
@@ -139,6 +139,27 @@ Examples of using the Linux-provided gdb helpers
       start_comm = "swapper/2\000\000\000\000\000\000"
     }
 
+ o Dig into a radix tree data structure, such as the IRQ descriptors:
+    (gdb) print (struct irq_desc)$lx_radix_tree_lookup(irq_desc_tree, 18)
+    $6 = {
+      irq_common_data = {
+        state_use_accessors = 67584,
+        handler_data = 0x0 <__vectors_start>,
+        msi_desc = 0x0 <__vectors_start>,
+        affinity = {{
+            bits = {65535}
+          }}
+      },
+      irq_data = {
+        mask = 0,
+        irq = 18,
+        hwirq = 27,
+        common = 0xee803d80,
+        chip = 0xc0eb0854 <gic_data>,
+        domain = 0xee808000,
+        parent_data = 0x0 <__vectors_start>,
+        chip_data = 0xc0eb0854 <gic_data>
+      } <... trimmed ...>
 
 List of commands and functions
 ------------------------------