tools: cuda_cycle.sh - detect channels from dmesg (client timeout is ~30 s)

The client times out the context-init counter wait in ~30 s; the previous
poll loop spent ~50 s on chan_dump round-trips before injecting. Count the
per-channel first-pump log lines straight from dmesg every 0.5 s instead.

1 files changed, 6 insertions, 5 deletions

diff --git a/tools/guest-diag/cuda_cycle.sh b/tools/guest-diag/cuda_cycle.sh
index 19143a2..cc333fb 100755
--- a/tools/guest-diag/cuda_cycle.sh
+++ b/tools/guest-diag/cuda_cycle.sh
@@ -33,15 +33,16 @@ timeout 30 "$VMEXEC" exec \
     >/dev/null 2>&1
 
 echo "[*] waiting for 20 GR channels"
-for i in $(seq 1 90); do
-    sleep 2
-    echo 1 | sudo tee /sys/module/open_iov_vfio/parameters/chan_dump >/dev/null
-    sleep 1
-    n=$(sudo dmesg -T | grep "sema-chan-dump" | grep "eng=0" | wc -l)
+# The client times out its context-init wait in ~30 s, so detection must be
+# cheap: count the per-channel first-pump log lines straight from dmesg
+# instead of round-tripping through the chan_dump parameter every second.
+for i in $(seq 1 240); do
+    n=$(sudo dmesg -T | grep -c "sema-chan: h=0x5c" || true)
     if [ "$n" -ge 20 ]; then
         echo "    GR channels up (poll $i)"
         break
     fi
+    sleep 0.5
 done
 
 echo "[*] injecting counters"