From a66693417602bd70d2c06ed9e0b124eb6a49f76c Mon Sep 17 00:00:00 2001
From: Andrea Bocci <andrea.bocci@cern.ch>
Date: Wed, 26 Aug 2020 21:43:02 +0200
Subject: [PATCH] HcalDigisProducerGPU: preallocate pinned host memory only if
 CUDA is available (#543)

---
 .../plugins/HcalDigisProducerGPU.cc           | 30 ++++++++++---------
 1 file changed, 16 insertions(+), 14 deletions(-)

diff --git a/EventFilter/HcalRawToDigi/plugins/HcalDigisProducerGPU.cc b/EventFilter/HcalRawToDigi/plugins/HcalDigisProducerGPU.cc
index d5b6d42d0ed2c..4a69b7f425e73 100644
--- a/EventFilter/HcalRawToDigi/plugins/HcalDigisProducerGPU.cc
+++ b/EventFilter/HcalRawToDigi/plugins/HcalDigisProducerGPU.cc
@@ -92,12 +92,17 @@ HcalDigisProducerGPU::HcalDigisProducerGPU(const edm::ParameterSet& ps)
 
   // this is a preallocation for the max statically known number of time samples
   // actual stride/nsamples will be inferred from data
-  hf5_.stride = hcal::compute_stride<hcal::Flavor5>(HBHEDataFrame::MAXSAMPLES);
   hf01_.stride = hcal::compute_stride<hcal::Flavor01>(QIE11DigiCollection::MAXSAMPLES);
+  hf5_.stride = hcal::compute_stride<hcal::Flavor5>(HBHEDataFrame::MAXSAMPLES);
   hf3_.stride = hcal::compute_stride<hcal::Flavor3>(QIE11DigiCollection::MAXSAMPLES);
-  hf01_.reserve(config_.maxChannelsF01HE);
-  hf5_.reserve(config_.maxChannelsF5HB);
-  hf3_.reserve(config_.maxChannelsF3HB);
+
+  // preallocate pinned host memory only if CUDA is available
+  edm::Service<CUDAService> cs;
+  if (cs and cs->enabled()) {
+    hf01_.reserve(config_.maxChannelsF01HE);
+    hf5_.reserve(config_.maxChannelsF5HB);
+    hf3_.reserve(config_.maxChannelsF3HB);
+  }
 }
 
 void HcalDigisProducerGPU::acquire(edm::Event const& event,
@@ -117,17 +122,15 @@ void HcalDigisProducerGPU::acquire(edm::Event const& event,
   event.getByToken(hbheDigiToken_, hbheDigis);
   event.getByToken(qie11DigiToken_, qie11Digis);
 
-
   // init f5 collection
   if (hbheDigis->size() > 0) {
     auto const nsamples = (*hbheDigis)[0].size();
     auto const stride = hcal::compute_stride<hcal::Flavor5>(nsamples);
     hf5_.stride = stride;
-  
+
     // flavor5 get device blobs
     df5_.stride = stride;
-    df5_.data = cms::cuda::make_device_unique<uint16_t[]>(
-      config_.maxChannelsF5HB * stride, ctx.stream());
+    df5_.data = cms::cuda::make_device_unique<uint16_t[]>(config_.maxChannelsF5HB * stride, ctx.stream());
     df5_.ids = cms::cuda::make_device_unique<uint32_t[]>(config_.maxChannelsF5HB, ctx.stream());
     df5_.npresamples = cms::cuda::make_device_unique<uint8_t[]>(config_.maxChannelsF5HB, ctx.stream());
   }
@@ -139,17 +142,15 @@ void HcalDigisProducerGPU::acquire(edm::Event const& event,
 
     hf01_.stride = stride01;
     hf3_.stride = stride3;
-  
+
     // flavor 0/1 get devie blobs
     df01_.stride = stride01;
-    df01_.data = cms::cuda::make_device_unique<uint16_t[]>(
-      config_.maxChannelsF01HE * stride01, ctx.stream());
+    df01_.data = cms::cuda::make_device_unique<uint16_t[]>(config_.maxChannelsF01HE * stride01, ctx.stream());
     df01_.ids = cms::cuda::make_device_unique<uint32_t[]>(config_.maxChannelsF01HE, ctx.stream());
 
     // flavor3 get device blobs
     df3_.stride = stride3;
-    df3_.data = cms::cuda::make_device_unique<uint16_t[]>(
-      config_.maxChannelsF3HB * stride3, ctx.stream());
+    df3_.data = cms::cuda::make_device_unique<uint16_t[]>(config_.maxChannelsF3HB * stride3, ctx.stream());
     df3_.ids = cms::cuda::make_device_unique<uint32_t[]>(config_.maxChannelsF3HB, ctx.stream());
   }
 
@@ -199,7 +200,8 @@ void HcalDigisProducerGPU::acquire(edm::Event const& event,
   }
 
   auto lambdaToTransfer = [&ctx](auto* dest, auto const& src) {
-    if (src.size() == 0) return;
+    if (src.size() == 0)
+      return;
     using vector_type = typename std::remove_reference<decltype(src)>::type;
     using type = typename vector_type::value_type;
     using dest_data_type = typename std::remove_pointer<decltype(dest)>::type;