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BP5 read direct to application memory
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@eisenhauer
eisenhauer committed Nov 24, 2022
1 parent b53bdc7 commit 12aa179
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Showing 2 changed files with 97 additions and 22 deletions.
114 changes: 93 additions & 21 deletions source/adios2/toolkit/format/bp5/BP5Deserializer.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1219,6 +1219,7 @@ bool BP5Deserializer::QueueGetSingle(core::VariableBase &variable,
Req.Count = variable.m_Count;
}
Req.Data = DestData;
Req.MemSpace = MemSpace;
Req.Step = Step;
PendingRequests.push_back(Req);
}
Expand Down Expand Up @@ -1298,6 +1299,26 @@ static size_t CalcBlockLength(const size_t dimensionsSize, const size_t *count)
return len;
}

/*
* Return true if for Req and data source info given by offsets and count,
* this a transfer of a contiguous block of memory into another
* contiguous block of memory. In its current usage, its OK if this
* function returns false in circumstances where the data is really
* contiguous, but it should never return true when it is not
* contiguous.
*/
bool BP5Deserializer::IsContiguousTransfer(BP5ArrayRequest *Req,
size_t *offsets, size_t *count)
{
/*
* All 1 dimensional requests in ADIOS involve the transfer of
* contiguous blocks. Multidimensional requests may or may not
* involve contiguous blocks, but for now all multimensional
* requests are assumed to be non-contiguous.
*/
return (Req->VarRec->DimCount == 1);
}

std::vector<BP5Deserializer::ReadRequest>
BP5Deserializer::GenerateReadRequests(const bool doAllocTempBuffers,
size_t *maxReadSize)
Expand All @@ -1308,6 +1329,7 @@ BP5Deserializer::GenerateReadRequests(const bool doAllocTempBuffers,
for (size_t ReqIndex = 0; ReqIndex < PendingRequests.size(); ReqIndex++)
{
auto Req = &PendingRequests[ReqIndex];
VariableBase *VB = static_cast<VariableBase *>(Req->VarRec->Variable);
if (Req->RequestType == Local)
{
const size_t writerCohortSize = WriterCohortSize(Req->Step);
Expand Down Expand Up @@ -1336,20 +1358,41 @@ BP5Deserializer::GenerateReadRequests(const bool doAllocTempBuffers,
RR.StartOffset =
writer_meta_base->DataBlockLocation[NeededBlock];

RR.DirectToAppMemory = IsContiguousTransfer(
Req, &writer_meta_base->Offsets[StartDim],
&writer_meta_base->Count[StartDim]);
RR.ReadLength =
helper::GetDataTypeSize(Req->VarRec->Type) *
CalcBlockLength(Req->VarRec->DimCount,
&writer_meta_base->Count[StartDim]);
RR.DestinationAddr = nullptr;
if (doAllocTempBuffers)
RR.OffsetInBlock = 0;
if (RR.DirectToAppMemory)
{
RR.DestinationAddr = (char *)malloc(RR.ReadLength);
RR.DestinationAddr = (char *)Req->Data;
if (Req->Start.size() != 0)
{
RR.ReadLength =
helper::GetDataTypeSize(Req->VarRec->Type) *
CalcBlockLength(Req->VarRec->DimCount,
Req->Count.data());
/* DirectToAppMemory handles only 1D, so offset calc
* is 1D only for the moment */
RR.StartOffset +=
helper::GetDataTypeSize(Req->VarRec->Type) *
Req->Start[0];
}
}
else
{
RR.DestinationAddr = nullptr;
if (doAllocTempBuffers)
{
RR.DestinationAddr = (char *)malloc(RR.ReadLength);
}
*maxReadSize =
(*maxReadSize < RR.ReadLength ? RR.ReadLength
: *maxReadSize);
}
*maxReadSize =
(*maxReadSize < RR.ReadLength ? RR.ReadLength
: *maxReadSize);
RR.Internal = NULL;
RR.OffsetInBlock = 0;
RR.ReqIndex = ReqIndex;
RR.BlockID = NeededBlock;
Ret.push_back(RR);
Expand All @@ -1375,6 +1418,7 @@ BP5Deserializer::GenerateReadRequests(const bool doAllocTempBuffers,
Block++)
{
std::array<size_t, helper::MAX_DIMS> intersectionstart;
std::array<size_t, helper::MAX_DIMS> intersectionend;
std::array<size_t, helper::MAX_DIMS> intersectioncount;

size_t StartDim = Block * Req->VarRec->DimCount;
Expand Down Expand Up @@ -1404,16 +1448,14 @@ BP5Deserializer::GenerateReadRequests(const bool doAllocTempBuffers,
*maxReadSize =
(*maxReadSize < RR.ReadLength ? RR.ReadLength
: *maxReadSize);
RR.Internal = NULL;
RR.DirectToAppMemory = false;
RR.ReqIndex = ReqIndex;
RR.BlockID = Block;
RR.OffsetInBlock = 0;
Ret.push_back(RR);
}
else
{
VariableBase *VB = static_cast<VariableBase *>(
Req->VarRec->Variable);
for (size_t Dim = 0; Dim < Req->VarRec->DimCount;
Dim++)
{
Expand All @@ -1429,14 +1471,15 @@ BP5Deserializer::GenerateReadRequests(const bool doAllocTempBuffers,
for (size_t Dim = 0; Dim < Req->VarRec->DimCount;
Dim++)
{
intersectionstart[Dim] +=
intersectioncount[Dim] - 1;
intersectionend[Dim] = intersectionstart[Dim] +
intersectioncount[Dim] -
1;
}
size_t EndOffsetInBlock =
VB->m_ElementSize *
(LinearIndex(Req->VarRec->DimCount,
&writer_meta_base->Count[StartDim],
&intersectionstart[0],
&intersectionend[0],
m_ReaderIsRowMajor) +
1);
ReadRequest RR;
Expand All @@ -1447,16 +1490,40 @@ BP5Deserializer::GenerateReadRequests(const bool doAllocTempBuffers,
StartOffsetInBlock;
RR.ReadLength =
EndOffsetInBlock - StartOffsetInBlock;
RR.DestinationAddr = nullptr;
if (doAllocTempBuffers)
RR.DirectToAppMemory = IsContiguousTransfer(
Req, &writer_meta_base->Offsets[StartDim],
&writer_meta_base->Count[StartDim]);
if (RR.DirectToAppMemory)
{
/*
* DirectToAppMemory handles only 1D, so offset
* calc is 1D only for the moment ContigOffset
* handles the case where our destination is not
* the start of the destination memory (because
* some other block filled in that start)
*/

ssize_t ContigOffset =
(writer_meta_base->Offsets[StartDim + 0] -
Req->Start[0]) *
VB->m_ElementSize;
if (ContigOffset < 0)
ContigOffset = 0;
RR.DestinationAddr =
(char *)malloc(RR.ReadLength);
(char *)Req->Data + ContigOffset;
}
else
{
RR.DestinationAddr = nullptr;
if (doAllocTempBuffers)
{
RR.DestinationAddr =
(char *)malloc(RR.ReadLength);
}
*maxReadSize = (*maxReadSize < RR.ReadLength
? RR.ReadLength
: *maxReadSize);
}
*maxReadSize =
(*maxReadSize < RR.ReadLength ? RR.ReadLength
: *maxReadSize);
RR.Internal = NULL;
RR.OffsetInBlock = StartOffsetInBlock;
RR.ReqIndex = ReqIndex;
RR.BlockID = Block;
Expand All @@ -1473,6 +1540,11 @@ BP5Deserializer::GenerateReadRequests(const bool doAllocTempBuffers,
void BP5Deserializer::FinalizeGet(const ReadRequest &Read, const bool freeAddr)
{
auto Req = PendingRequests[Read.ReqIndex];

// if we could do this, nothing else to do
if (Read.DirectToAppMemory)
return;

int ElementSize = Req.VarRec->ElementSize;
MetaArrayRec *writer_meta_base =
(MetaArrayRec *)GetMetadataBase(Req.VarRec, Req.Step, Read.WriterRank);
Expand Down
5 changes: 4 additions & 1 deletion source/adios2/toolkit/format/bp5/BP5Deserializer.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -47,7 +47,7 @@ class BP5Deserializer : virtual public BP5Base
size_t StartOffset;
size_t ReadLength;
char *DestinationAddr;
void *Internal;
bool DirectToAppMemory;
size_t ReqIndex;
size_t OffsetInBlock;
size_t BlockID;
Expand Down Expand Up @@ -230,6 +230,9 @@ class BP5Deserializer : virtual public BP5Base
std::vector<BP5ArrayRequest> PendingRequests;
void *GetMetadataBase(BP5VarRec *VarRec, size_t Step,
size_t WriterRank) const;
bool IsContiguousTransfer(BP5ArrayRequest *Req, size_t *offsets,
size_t *count);

size_t CurTimestep = 0;

/* We assume operators are not thread-safe, call Decompress() one at a time
Expand Down

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