[SYCL] Fix working with subbuffers with non-nil offset

[s-kanaev]

No description provided.

[s-kanaev]

getOrCreateAllocaForReq() method contains a proper procedure to create/find alloca cmd for subbuffer. That is why there is this kind of hack: regardless of whether alloca commands collection is non-empty go on and getOrCreate it. The method will lookup for it in first place, though. It'll not find the correct alloca command 'cause there is no equality of MOffsetInBytes. After that the method will create a proper alloca cmd for subbuffer.

[s-kanaev]

Another approach here might be to check if SrcAllocaCmd is null and create it the same way getOrCreateAllocaForReq does if IsSuitableSubReq(Req) returns true. Thing is, this approach would violate code reuse. Although after refactoring there will be more places to edit in case of logic change.

[s-kanaev]

The second commit implements this second approach. And fixes faults on GPU which were added with first commit.

[romanovvlad]

Suggest doing something like this instead:

  diff --git a/sycl/source/detail/scheduler/graph_builder.cpp b/sycl/source/detail/scheduler/graph_builder.cpp
  index b150f66..6c5b682 100644
  --- a/sycl/source/detail/scheduler/graph_builder.cpp
  +++ b/sycl/source/detail/scheduler/graph_builder.cpp
  @@ -320,14 +320,21 @@ Command *Scheduler::GraphBuilder::addHostAccessor(Requirement *Req) {
  ·
     AllocaCommandBase *SrcAllocaCmd = nullptr;
  ·
  -  if (Record->MAllocaCommands.empty())
  -    SrcAllocaCmd = getOrCreateAllocaForReq(Record, Req, HostQueue);
  -  else
  -    SrcAllocaCmd = findAllocaForReq(Record, Req, Record->MCurContext);
  +  AllocaCommandBase *HostAllocaCmd =
  +      getOrCreateAllocaForReq(Record, Req, HostQueue);
  ·
  -  if (!SrcAllocaCmd->getQueue()->is_host())
  +  if (!sameCtx(HostAllocaCmd->getQueue()->get_context_impl(),
  +               Record->MCurContext))
       insertMemoryMove(Record, Req, HostQueue);
  ·
  +  //if (Record->MAllocaCommands.empty())
  +    //SrcAllocaCmd = getOrCreateAllocaForReq(Record, Req, HostQueue);
  +  //else
  +    //SrcAllocaCmd = findAllocaForReq(Record, Req, Record->MCurContext);
  +
  +  //if (!SrcAllocaCmd->getQueue()->is_host())
  +    //insertMemoryMove(Record, Req, HostQueue);
  +
     Command *UpdateHostAccCmd = insertUpdateHostReqCmd(Record, Req, HostQueue);
  ·
     // Need empty command to be blocked until host accessor is destructed

[s-kanaev]

Suggest doing something like this instead:

Done

[KarachunIvan]

LGTM

[alexbatashev]

LGTM