diff options
| -rw-r--r-- | kernel/gsp_sema_service.c | 43 |
1 files changed, 41 insertions, 2 deletions
diff --git a/kernel/gsp_sema_service.c b/kernel/gsp_sema_service.c index b2cf8a5..a3366ba 100644 --- a/kernel/gsp_sema_service.c +++ b/kernel/gsp_sema_service.c @@ -20705,6 +20705,42 @@ static bool svc_gr_arg_defer_ok(u64 push_va) } /* + * r556: the ABSOLUTE per-launch deferral cap. Every defer path (r541 + * dstpend, r543 partial args, m150 data-stalled hold, busy-defer re-holds) + * is individually bounded, but the bounds interact and re-arm across + * re-decode passes; the r553/r555 boots show clients still walking these + * loops for 400+ s (victory_reduce 430 s, victory_saxpy 254 s at write + * time, work_guard deferred climbing by the thousand). This is the single + * backstop that makes "a launch can never be deferred for more than + * SVC_GR_DEFER_CAP_MS" true regardless of which guard keeps winning: the + * first sighting of a push VA arms an absolute deadline; once it passes, + * svc_gr_defer_expired() returns true and every defer site forwards + * best-effort. 15 s is well above the 0.5-2 s pin latency the deferrals + * exist to cover and well below every client-side timeout (>= 60 s). + */ +#define SVC_GR_DEFER_CAP_MS 15000u +static u64 svc_gr_defer_cap_va[SVC_GR_ARG_DEFER_SLOTS]; +static unsigned long svc_gr_defer_cap_j[SVC_GR_ARG_DEFER_SLOTS]; +static u32 svc_gr_defer_cap_pos; + +static bool svc_gr_defer_expired(u64 push_va) +{ + u32 i; + + if (!push_va) + return false; + for (i = 0; i < SVC_GR_ARG_DEFER_SLOTS; i++) { + if (svc_gr_defer_cap_va[i] == push_va) + return !time_before(jiffies, svc_gr_defer_cap_j[i] + + msecs_to_jiffies(SVC_GR_DEFER_CAP_MS)); + } + i = svc_gr_defer_cap_pos++ % SVC_GR_ARG_DEFER_SLOTS; + svc_gr_defer_cap_va[i] = push_va; + svc_gr_defer_cap_j[i] = jiffies; + return false; +} + +/* * r548: is a forward still OWED for this push VA - a captured, never * offered candidate sitting in the candidate ring? The r547 saxpy stall: * both launches were deferred by the r541/r543 guards, the candidate ring @@ -20887,7 +20923,8 @@ static bool svc_gr_request(struct nv_vgpu_device *vgpu, * busy-defer + gr_hold machinery as every other busy refusal, so it * can never hang the launch. */ - if (svc_gr_dstpend_overlap()) { + if (svc_gr_dstpend_overlap() && + !svc_gr_defer_expired(svc_gr_cand.push_va)) { clear_bit_unlock(SVC_FWD_INFLIGHT, &svc_fwd_state); mutex_unlock(&svc_fwd_lock); svc_gr_busy_defer = true; @@ -20913,6 +20950,7 @@ static bool svc_gr_request(struct nv_vgpu_device *vgpu, * delays, it cannot hang. */ if (svc_fwd_req.gr_arg_partial && !svc_gr_data_stalled && + !svc_gr_defer_expired(svc_gr_cand.push_va) && svc_gr_arg_defer_ok(svc_gr_cand.push_va)) { clear_bit_unlock(SVC_FWD_INFLIGHT, &svc_fwd_state); mutex_unlock(&svc_fwd_lock); @@ -20978,7 +21016,8 @@ static bool svc_gr_request(struct nv_vgpu_device *vgpu, } } } - if (svc_gr_data_stalled) { + if (svc_gr_data_stalled && + !svc_gr_defer_expired(svc_gr_cand.push_va)) { clear_bit_unlock(SVC_FWD_INFLIGHT, &svc_fwd_state); mutex_unlock(&svc_fwd_lock); svc.fwd_gr_refused++; |