diff options
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/guest-diag/guest_pin_stream.py | 24 |
1 files changed, 22 insertions, 2 deletions
diff --git a/tools/guest-diag/guest_pin_stream.py b/tools/guest-diag/guest_pin_stream.py index 8d0b34d..717a05d 100644 --- a/tools/guest-diag/guest_pin_stream.py +++ b/tools/guest-diag/guest_pin_stream.py @@ -141,6 +141,26 @@ def main(): time.sleep(INTERVAL) continue dt = time.time() - t0 + # Diagnostic: the GR completion-counter page is the one page the + # client's context-init wait polls; log its pagemap entry every loop + # so a scan blind spot is visible in the guest log. + cpm = None + try: + fdp = os.open('/proc/%d/pagemap' % pid, os.O_RDONLY) + os.lseek(fdp, (0x20400fec0 // 4096) * 8, 0) + cpm = int.from_bytes(os.read(fdp, 8), 'little') + os.close(fdp) + except OSError: + cpm = None + diag = ('cpm=%s' % ('present' if (cpm or 0) >> 63 & 1 else 'absent') + if cpm is not None else 'cpm=ERR') + # Guaranteed fast path for the GR completion-counter page: if the + # window scan misses it (observed once), add it explicitly so the host + # can register the slots before the client's first wait. + if cpm is not None and (cpm >> 63) & 1: + cpa = (cpm & ((1 << 55) - 1)) << 12 + if cpa and (not PAMAX or cpa < PAMAX): + cur[0x20400f000] = cpa new = [(va, pa) for va, pa in cur.items() if seen.get(va) != pa] seen = cur lines = [] @@ -152,9 +172,9 @@ def main(): last_log = now try: with open('/tmp/guest_pin_stream.log', 'a') as f: - f.write('%s pid=%s present=%d new=%d sem=%d scan=%.3fs\n' + f.write('%s pid=%s present=%d new=%d sem=%d scan=%.3fs %s\n' % (time.strftime('%T'), pid, len(cur), len(new), - len(seen_sems), dt)) + len(seen_sems), dt, diag)) except OSError: pass if not new and not lines: |