diff options
Diffstat (limited to 'kernel/gsp_sema_service.c')
| -rw-r--r-- | kernel/gsp_sema_service.c | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/kernel/gsp_sema_service.c b/kernel/gsp_sema_service.c index 4a86235..aa56c5e 100644 --- a/kernel/gsp_sema_service.c +++ b/kernel/gsp_sema_service.c @@ -194,6 +194,28 @@ struct svc_channel { * reset (PUT dropping below put_prev) resyncs * last_get to slot 0 so the live first push is * processed instead of skipped. */ + bool gr_pub_armed; /* mm2 (r207/r208 second-client hang): a GR + * channel's completion word may only receive a + * GP_PUT publish after the channel has been + * proven to belong to the CURRENT session. A + * GR ring/USERD surviving in its fixed VRAM + * slot from the previous session reads a + * residual put at discovery (e.g. 109/112); + * publishing that residual put into the + * channel's own word (8c634144 made the target + * release_pa - the client's waited word) while + * the stale ring is consumed poisons the fresh + * client's UVM tracking semaphore: its + * completed_value observes a far-forward + * payload, the later reset/release sequence is + * a >MAX_JUMP (2*entries) downward observation, + * and the fresh session's first waits wedge + * (matmul: one GR push per channel then 242 s + * silent). Armed when a GR channel is seen with + * put <= 1 (pristine ring) or when the fresh- + * put-drop rewind proves a session switch; the + * rewind also voids any publish state the + * stale pass advanced. */ bool logged; /* one state log per channel */ bool pool_rel_seen; /* ISSUE-0002 r70: a pool release word for * this channel has been read through a @@ -11528,6 +11550,27 @@ static void svc_counter_publish(struct nv_vgpu_device *vgpu, } svc_counter_flush_pending(vgpu, ch); + /* + * mm2 (r207/r208 second-client hang): suppress the GR publish until + * the channel is proven to belong to the current session. During a + * fresh session's first pass the pump consumes the PREVIOUS + * session's residual ring; the completion gate above passes exactly + * then (the stale consumption satisfies last_get == put) and the + * residual put would land in the client's own completion word + * (release_pa). The fresh client's UVM then sees a far-forward + * payload followed by its real release sequence - a downward + * observation larger than UVM_GPU_SEMAPHORE_MAX_JUMP that corrupts + * the tracking counter and wedges the session's first waits (r207 + * victory_matmul: 1 GR push per channel, zero forwards, 242 s). + * gr_pub_armed is set at the fresh-put-drop rewind (session switch + * proven) or when a GR channel is seen with put <= 1 (pristine + * ring, nothing stale to mispublish); a live mid-stream discovery + * (put high, never dropping) loses only this catch-up publish, + * which the release applies already cover. + */ + if (!ch->engine_type && !ch->gr_pub_armed) + return; + val = put; if (val == ch->counter_last) return; @@ -15290,6 +15333,20 @@ static void svc_pump_channels(struct nv_vgpu_device *vgpu) ch->logged = true; } + /* + * mm2: a GR channel whose USERD already reads PUT <= 1 cannot + * hold a stale consumed prefix, so its publishes (the catch-up + * for releases missing from consumed entries) are safe to + * enable immediately - this is the pristine first-boot ring. + * Channels discovered with a residual put stay unarmed until + * the fresh-put-drop rewind proves the session switch, so the + * residual put can never reach the fresh client's completion + * word (see gr_pub_armed and svc_counter_publish). + */ + if (!ch->engine_type && !ch->gr_pub_armed && put <= 1 && + !ch->userd_wait_fresh) + ch->gr_pub_armed = true; + /* Initialize expected semaphore payload from the pool (if mapped). */ svc_init_expected_payload(vgpu, ch); @@ -15384,6 +15441,36 @@ static void svc_pump_channels(struct nv_vgpu_device *vgpu) ch->h_object, ch->gr_index, put, (u32)ch->last_get); ch->last_get = 0; + /* + * mm2: the session switch is now proven - arm + * the publish for the live entries that follow, + * and void any publish state the stale pass + * advanced. Everything consumed to reach + * last_get was the dead session's ring; a + * publish issued on it wrote the residual put + * into the very word the fresh client waits on + * (its tracking semaphore; pub target is + * release_pa since 8c634144) and the + * forward-only apply then skips the real + * release payloads that follow. Re-arm the + * word to 0 and reset the catch-up bookkeeping + * so the re-decoded live releases re-advance + * it from the client's own sequence (1, 2, + * ...). Idempotent when no stale publish + * happened (counter_last == 0). + */ + ch->gr_pub_armed = true; + if (ch->counter_last) { + u64 upa = ch->release_pa ? + ch->release_pa : ch->counter_pa; + u32 zero = 0; + + if (upa) + (void)svc_write_ap(vgpu, upa, + SVC_APERTURE_SYS, + &zero, sizeof(zero)); + ch->counter_last = 0; + } } bitmap_zero(ch->slot_done_epoch, SVC_GPFIFO_MAX_BITS); } |