I'm running into a problme with Ocelot, the MonetDB with OpenCL extension. I apologize if this is not the right forum to post.
I'm seeing a query failure which was caused by MoneDB-OpenCL trying to cache an empty BAT and ended up calling clCreateBuffer with a 0 size buffer and failed. Any select with a where clause would trigger it.
Has anyone seen this too? It fails whether I use 32 bit or 64 bit oid, Nvidia or AMD. I'm trying to figure if it's a real issue or if I'm missing anything. Any input greatly appreciated.
The database was generated by TPC-H dbgen (details below). The query I used was "select c_custkey, c_name from customer where c_custkey < 2", and here's a trace of the sequence of calls leading to the failure starting from the MAL statement:
1) X_52 := ocelot.thetasubselect(r1_10,A0,"<",0);(see log below)
2) ocl_select.c::ocl_subselect() line 142: ocl_cacheBAT
3) ocl_memmanager.c::ocl_cacheBAT() line 771: allocateBuffer
4) ocl_memmanager.c::allocateBuffer() line 432: clCreateBuffer
===== Source version and environment =====
1) Ocelot src installed from zip downloaded from monetdb-opencl:
msaecker-monetdb-opencl-b513b35eb84a.zip
2) Ocelot configure options:
./configure --prefix=/usr/local --enable-oid32 --enable-optimize --disable-test
ing --disable-developer --disable-debug --disable-assert --enable-sql --enable-m
onetdb5 --with-opencl=/usr
3) Operating System: Fedora 17 kernel 3.9.10-100
4) Hardware: NVIDIA GTX570 on Intel i7-3820 w/ 16GB mem
5) OpenCL: Nvidia OpenCL that came with CUDA 5.5 SDK
6) Database: generated w/ TPC-H dbgen using size factor s=0.01
===== operation log follows =====
[root@gen3-2 ocelot]# mclient -ddb001 -lmal
mal>ocelot.init();
mal>ocelot.listDevices();
# Device 0: NVIDIA Corporation - GeForce GTX 570 (default device)
mal>\q
[root@gen3-2 ocelot]# mclient -ddb001 -lsql
sql>\d
TABLE sys.customer
TABLE sys.lineitem
TABLE sys.nation
TABLE sys.orders
TABLE sys.part
TABLE sys.partsupp
TABLE sys.region
TABLE sys.supplier
sql>\d customer
CREATE TABLE "sys"."customer" (
"c_custkey" INTEGER NOT NULL,
"c_name" VARCHAR(25) NOT NULL,
"c_address" VARCHAR(40) NOT NULL,
"c_nationkey" INTEGER NOT NULL,
"c_phone" VARCHAR(15) NOT NULL,
"c_acctbal" DECIMAL(15,2) NOT NULL,
"c_mktsegment" VARCHAR(10) NOT NULL,
"c_comment" VARCHAR(117) NOT NULL,
CONSTRAINT "customer_c_custkey_pkey" PRIMARY KEY ("c_custkey"),
CONSTRAINT "customer_c_nationkey_fkey" FOREIGN KEY ("c_nationkey") REFERENCES "sys"."nation" ("n_nationkey")
);
sql>select count(*) from customer;
+------+
| L1 |
+======+
| 1500 |
+------+
1 tuple (1.311ms)
sql>select c_custkey, c_name from customer where c_custkey < 2;
+-----------+--------------------+
| c_custkey | c_name |
+===========+====================+
| 1 | Customer#000000001 |
+-----------+--------------------+
1 tuple (1.776ms)
sql>set optimizer='cl_pipe';
operation successful (0.981ms)
sql>select c_custkey, c_name from customer where c_custkey < 2;
invalid/unknown response from server, ignoring output
? #Could not allocate OpenCL buffer of size: 0.
Error caching input BAT.
sql>
sql>explain select c_custkey, c_name from customer where c_custkey < 2;
+------------------------------------------------------------------------------+
| mal
+==============================================================================+
| function user.s9_1{autoCommit=true}(A0:int):void; |
| ocelot.beginQuery(); |
| X_3 := sql.mvc(); |
| X_7 := sql.bind(X_3,"sys","customer","c_custkey",0); |
| X_4:bat[:oid,:oid] := sql.tid(X_3,"sys","customer"); |
| X_51 := ocelot.thetasubselect(X_7,X_4,A0,"<",0); |
| (X_10,r1_10) := sql.bind(X_3,"sys","customer","c_custkey",2); |
| X_52 := ocelot.thetasubselect(r1_10,A0,"<",0); |
| X_13 := sql.bind(X_3,"sys","customer","c_custkey",1); |
| X_53 := ocelot.thetasubselect(X_13,X_4,A0,"<",0); |
| ocelot.sync(X_51); |
| ocelot.sync(X_52); |
| ocelot.sync(X_53); |
| X_15 := sql.subdelta(X_51,X_4,X_10,X_52,X_53); |
| X_17 := sql.projectdelta(X_15,X_7,X_10,r1_10,X_13); |
| X_18 := sql.bind(X_3,"sys","customer","c_name",0); |
| (X_20,r1_23) := sql.bind(X_3,"sys","customer","c_name",2); |
| X_22 := sql.bind(X_3,"sys","customer","c_name",1); |
| X_23 := sql.projectdelta(X_15,X_18,X_20,r1_23,X_22); |
| X_24 := sql.resultSet(2,1,X_17); |
| sql.rsColumn(X_24,"sys.customer","c_custkey","int",32,0,X_17); |
| sql.rsColumn(X_24,"sys.customer","c_name","varchar",25,0,X_23); |
| X_32 := io.stdout(); |
| sql.exportResult(X_32,X_24); |
| ocelot.endQuery(); |
| end s9_1; |
| # querylog.define("explain select c_custkey, c_name from customer where c_cu |
: stkey < 2;","cl_pipe") :
+------------------------------------------------------------------------------+
27 tuples (1.408ms)
sql>
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