diff options
Diffstat (limited to 'tools/sched_ext/scx_qmap.bpf.c')
| -rw-r--r-- | tools/sched_ext/scx_qmap.bpf.c | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/tools/sched_ext/scx_qmap.bpf.c b/tools/sched_ext/scx_qmap.bpf.c index 5d1f880d1149..e952f525599b 100644 --- a/tools/sched_ext/scx_qmap.bpf.c +++ b/tools/sched_ext/scx_qmap.bpf.c @@ -56,7 +56,8 @@ struct qmap { queue1 SEC(".maps"), queue2 SEC(".maps"), queue3 SEC(".maps"), - queue4 SEC(".maps"); + queue4 SEC(".maps"), + dump_store SEC(".maps"); struct { __uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS); @@ -578,11 +579,26 @@ void BPF_STRUCT_OPS(qmap_dump, struct scx_dump_ctx *dctx) return; scx_bpf_dump("QMAP FIFO[%d]:", i); + + /* + * Dump can be invoked anytime and there is no way to iterate in + * a non-destructive way. Pop and store in dump_store and then + * restore afterwards. If racing against new enqueues, ordering + * can get mixed up. + */ bpf_repeat(4096) { if (bpf_map_pop_elem(fifo, &pid)) break; + bpf_map_push_elem(&dump_store, &pid, 0); scx_bpf_dump(" %d", pid); } + + bpf_repeat(4096) { + if (bpf_map_pop_elem(&dump_store, &pid)) + break; + bpf_map_push_elem(fifo, &pid, 0); + } + scx_bpf_dump("\n"); } } |