Use CuArrays.usage_limit[] to improve stability

src/Knet.jl

@@ -150,12 +150,17 @@ dir(path...) = joinpath(dirname(@__DIR__),path...)
 # See if we have a gpu at initialization:
 function __init__()
     try
-        r = gpu(true)
-        r >= 0 && AutoGrad.set_gc_function(knetgcnode)
-        #@info(r >= 0 ? "Knet using GPU $r" : "No GPU found, Knet using the CPU")
+        dev = gpu(true)
+        if dev >= 0
+            CuArrays.usage_limit[] = gpufree() - 100_000_000
+            AutoGrad.set_gc_function(knetgcnode)
+            @debug "Knet using GPU $dev"
+        else
+            @debug "No GPU found, Knet using the CPU"
+        end
     catch e
         gpu(false)
-        #@warn("Knet using the CPU: $e")
+        @warn "Knet cannot use the GPU: $e"
     end
 end
 

src/cuarray.jl

@@ -2,7 +2,7 @@
 
 if find_cuda_library("cuda", tk) != nothing # has_cuda()
     try
-        using CuArrays: CuPtr, unsafe_free!
+        using CuArrays: CuArrays, CuPtr, unsafe_free!, usage_limit
         import CuArrays: CuArray
     catch ex
         @warn "CUDA is installed, but CuArrays.jl fails to load" exception=(ex,catch_backtrace())

test/binary.jl

@@ -1,7 +1,8 @@
 include("header.jl")
 #using Dates
 #date(x)=(join(stdout,[Dates.format(Dates.now(),"HH:MM:SS"), x,'\n'],' '); flush(stdout))
-date(x)=(println(round(Int,time())%3600, ':', x); flush(stdout))
+time0 = time()
+date(x)=(println(round(Int,time()-time0), ':', x); flush(stdout))
 macro dbg(_x); end
 #macro dbg(_x); :(@show $(esc(_x))); end