Here is a patch against crash v6.0.3rc24 that adds duplicate node
detection per-CPU for the CFS runqueue display in dump_CFS_runqueues()
for the runq command.

This resolves for that 6.0.3 rc the failure to bail-out of the unending
looping display I get with the crash dump I have that has a corrupted
CFS runqueue containing a loop.

Signed-off-by: David Mair <[email protected]>
---
 task.c |   11 ++++++++++-
 1 files changed, 10 insertions(+), 1 deletions(-)

diff --git a/task.c b/task.c
index c81cb74..7a3e8e1 100755
--- a/task.c
+++ b/task.c
@@ -7060,7 +7060,14 @@ dump_tasks_in_cfs_rq(ulong cfs_rq)
                                     OFFSET(sched_entity_run_node));
                if (!tc)
                        continue;
-               dump_task_runq_entry(tc);
+               if (hq_enter((ulong)tc)) {
+                       dump_task_runq_entry(tc);
+               } else {
+                       error(WARNING, "Duplicate CFS runqueue node, task %lx"
+                               ", probable loop\n",
+                               tc->task);
+                       return total;
+               }
                total++;
        }

@@ -7220,7 +7227,9 @@ dump_CFS_runqueues(void)

                fprintf(fp, "  CFS RB_ROOT: %lx\n", (ulong)root);

+               hq_open();
                tot = dump_tasks_in_cfs_rq(cfs_rq);
+               hq_close();
                if (!tot) {
                        INDENT(5);
                        fprintf(fp, "[no tasks queued]\n");

--
Crash-utility mailing list
[email protected]
https://www.redhat.com/mailman/listinfo/crash-utility

Reply via email to