diff options
| -rw-r--r-- | kernel/gsp_sema_service.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/kernel/gsp_sema_service.c b/kernel/gsp_sema_service.c index fa76162..e972732 100644 --- a/kernel/gsp_sema_service.c +++ b/kernel/gsp_sema_service.c @@ -13130,6 +13130,33 @@ static void svc_pump_channels(struct nv_vgpu_device *vgpu) if (ch->userd_wait_fresh) { ch->last_get = 0; ch->userd_wait_fresh = false; + } else if (ch->engine_type && ch->gpfifo_entries && + ch->last_get > put && + ch->submissions < ch->gpfifo_entries / 2) { + /* + * ISSUE-0002 (r73): a SECOND (or later) drop + * while the channel is still fresh. The + * discovery-time put was residual (the previous + * session's counter, e.g. 67) and the pump had + * already consumed the live entries 0..k; the + * guest's counter then settled at a value below + * the pump's read position (r73 rank2: put=1 + * with last_get=2 after the r48 resync). The + * loop condition last_get != put then marches + * forward through ~1023 slots the producer has + * not written in this epoch, holding each + * unreadable stale entry for the full CE grace + * (one fake release per 8 s) - the client + * appears wedged. Never stay ahead of the + * producer: rewind to its position. A genuine + * ring wrap cannot be fresh (it needs a full + * ring of submissions), so this cannot skip a + * live entry. + */ + pr_info_ratelimited("sema-chan: fresh put drop h=0x%x rank=%u put=%u last=%u -> rewind\n", + ch->h_object, ch->ce_index, put, + (u32)ch->last_get); + ch->last_get = put; } bitmap_zero(ch->slot_done_epoch, SVC_GPFIFO_MAX_BITS); } |