[Crash-utility] [PATCH 1/1] CFS runqueue loop detection
Here is a patch against crash v6.0.2 that adds duplicate node detection
per-CPU for the CFS runqueue display in dump_CFS_runqueues() for the
runq command.
This resolves 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 <dmair(a)suse.com>
---
task.c | 9 ++++++++-
1 files changed, 8 insertions(+), 1 deletions(-)
diff --git a/task.c b/task.c
index 433a043..0333fe8 100755
--- a/task.c
+++ b/task.c
@@ -7050,7 +7050,12 @@ dump_tasks_in_cfs_rq(ulong cfs_rq, ulong skip)
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++;
}
@@ -7217,10 +7222,12 @@ dump_CFS_runqueues(void)
fprintf(fp, " CFS RB_ROOT: %lx\n", (ulong)root);
tot = 0;
+ hq_open();
if (curr_cfs_rq)
tot += dump_tasks_in_cfs_rq(curr_cfs_rq, 0);
if (cfs_rq != curr_cfs_rq)
tot += dump_tasks_in_cfs_rq(cfs_rq, curr_cfs_rq);
+ hq_close();
if (!tot) {
INDENT(5);
fprintf(fp, "[no tasks queued]\n");