Michael Smith has submitted this change and it was merged. (
http://gerrit.cloudera.org:8080/20733 )
Change subject: IMPALA-11805: Use llvm ObjectCache for codegen caching
......................................................................
IMPALA-11805: Use llvm ObjectCache for codegen caching
Currently, we employ llvm::ExecutionEngine for codegen caching,
providing access to compiled functions within the cached engine.
However, the real challenge is the ExecutionEngine uses a lot of
memory which largely exceeds our memory estimates and it is very
hard to predict.
This patch addresses this issue by using llvm::ObjectCache for
codegen caching. In our case, each execution engine would have
only one module, and after the compilation of the module, the
compiled codegened functions of the module would be set to the
execution engine, therefore functions could be used by Impala.
During function compilation within the module, if an ObjectCache
is set to the execution engine, the compiled codegened functions
would be also written into the cache. This way, if we keep the
cache, when revisiting the same module (fragment), we can
efficiently reuse the specific ObjectCache, loading pre-compiled
codegened functions and saving time.
The tpch performance test indicates no significant regression
compared to the previous use of ExecutionEngine. Post-change,
the actual memory usage of each codegen caching entry is notably
reduced.
+----------+-----------------------+---------+------------+------------+----------------+
| Workload | File Format | Avg (s) | Delta(Avg) | GeoMean(s) |
Delta(GeoMean) |
+----------+-----------------------+---------+------------+------------+----------------+
| TPCH(1) | parquet / none / none | 0.22 | -0.65% | 0.20 | -0.75%
|
+----------+-----------------------+---------+------------+------------+----------------+
+----------+----------+-----------------------+--------+-------------+------------+------------+----------------+-------+----------------+---------+-------+
| Workload | Query | File Format | Avg(s) | Base Avg(s) |
Delta(Avg) | StdDev(%) | Base StdDev(%) | Iters | Median Diff(%) | MW Zval |
Tval |
+----------+----------+-----------------------+--------+-------------+------------+------------+----------------+-------+----------------+---------+-------+
| TPCH(1) | TPCH-Q13 | parquet / none / none | 0.49 | 0.47 | +2.80%
| 5.32% | 5.07% | 10 | +1.22% | 1.63 | 1.19 |
| TPCH(1) | TPCH-Q4 | parquet / none / none | 0.16 | 0.16 | +3.51%
| 1.32% | * 10.38% * | 10 | +0.06% | 0.49 | 1.06 |
| TPCH(1) | TPCH-Q11 | parquet / none / none | 0.12 | 0.12 | +1.39%
| 2.27% | 2.24% | 10 | +1.50% | 1.90 | 1.37 |
| TPCH(1) | TPCH-Q19 | parquet / none / none | 0.21 | 0.21 | +1.56%
| * 10.02% * | * 11.42% * | 10 | +1.18% | 0.57 | 0.32 |
| TPCH(1) | TPCH-Q18 | parquet / none / none | 0.27 | 0.27 | +1.71%
| 6.46% | 1.29% | 10 | -0.19% | -1.19 | 0.81 |
| TPCH(1) | TPCH-Q6 | parquet / none / none | 0.11 | 0.11 | +0.79%
| 2.76% | 2.15% | 10 | +0.10% | 1.46 | 0.71 |
| TPCH(1) | TPCH-Q3 | parquet / none / none | 0.26 | 0.26 | +0.71%
| 6.63% | 6.18% | 10 | +0.04% | 0.49 | 0.25 |
| TPCH(1) | TPCH-Q17 | parquet / none / none | 0.17 | 0.17 | +0.41%
| * 14.66% * | * 13.01% * | 10 | +0.05% | 0.40 | 0.07 |
| TPCH(1) | TPCH-Q14 | parquet / none / none | 0.16 | 0.16 | +0.19%
| 1.41% | 1.39% | 10 | +0.25% | 1.46 | 0.31 |
| TPCH(1) | TPCH-Q20 | parquet / none / none | 0.17 | 0.17 | +0.22%
| 1.70% | 1.77% | 10 | -0.05% | -0.40 | 0.28 |
| TPCH(1) | TPCH-Q12 | parquet / none / none | 0.16 | 0.16 | -0.27%
| 0.54% | 1.46% | 10 | +0.14% | 0.93 | -0.54 |
| TPCH(1) | TPCH-Q22 | parquet / none / none | 0.11 | 0.11 | -0.38%
| 0.81% | 2.06% | 10 | +0.03% | 0.22 | -0.54 |
| TPCH(1) | TPCH-Q16 | parquet / none / none | 0.17 | 0.17 | -0.38%
| 0.67% | 1.58% | 10 | -0.01% | -0.13 | -0.70 |
| TPCH(1) | TPCH-Q8 | parquet / none / none | 0.27 | 0.27 | -0.08%
| 1.24% | 1.15% | 10 | -0.33% | -1.37 | -0.15 |
| TPCH(1) | TPCH-Q15 | parquet / none / none | 0.16 | 0.16 | -1.18%
| * 16.61% * | * 10.25% * | 10 | +0.33% | 0.40 | -0.19 |
| TPCH(1) | TPCH-Q1 | parquet / none / none | 0.22 | 0.22 | -1.67%
| 1.62% | 7.45% | 10 | +0.43% | 1.02 | -0.70 |
| TPCH(1) | TPCH-Q5 | parquet / none / none | 0.22 | 0.22 | -0.98%
| 0.22% | 1.55% | 10 | -0.26% | -2.16 | -1.97 |
| TPCH(1) | TPCH-Q21 | parquet / none / none | 0.48 | 0.49 | -1.18%
| 3.58% | 4.40% | 10 | -0.25% | -1.19 | -0.66 |
| TPCH(1) | TPCH-Q10 | parquet / none / none | 0.26 | 0.26 | -1.93%
| 7.84% | 6.24% | 10 | -0.14% | -0.13 | -0.62 |
| TPCH(1) | TPCH-Q7 | parquet / none / none | 0.18 | 0.19 | -3.31%
| * 11.47% * | * 12.47% * | 10 | -0.25% | -1.72 | -0.63 |
| TPCH(1) | TPCH-Q9 | parquet / none / none | 0.34 | 0.35 | -5.22%
| 6.87% | * 10.03% * | 10 | -2.15% | -1.28 | -1.38 |
| TPCH(1) | TPCH-Q2 | parquet / none / none | 0.16 | 0.18 |
-11.00% | * 16.07% * | 3.84% | 10 | -0.90% | -1.81 |
-2.35 |
+----------+----------+-----------------------+--------+-------------+------------+------------+----------------+-------+----------------+---------+-------+
We are no longer using ExecutionEngine for caching, so we got rid of
the LlvmExecutionEngineWrapper class. Instead, we brought in a new
class CodeGenObjectCache to implement llvm::ObjectCache.
Testing:
Passed LlvmCodeGenCacheTest and custom_cluster/test_codegen_cache.py.
Change-Id: Ic3c1b46bb9018ed0320817141785a3bdc41fa677
Reviewed-on: http://gerrit.cloudera.org:8080/20733
Reviewed-by: Michael Smith <[email protected]>
Tested-by: Impala Public Jenkins <[email protected]>
---
M be/src/codegen/CMakeLists.txt
M be/src/codegen/llvm-codegen-cache-test.cc
M be/src/codegen/llvm-codegen-cache.cc
M be/src/codegen/llvm-codegen-cache.h
A be/src/codegen/llvm-codegen-object-cache.cc
A be/src/codegen/llvm-codegen-object-cache.h
M be/src/codegen/llvm-codegen.cc
M be/src/codegen/llvm-codegen.h
D be/src/codegen/llvm-execution-engine-wrapper.h
M be/src/runtime/test-env.h
M tests/custom_cluster/test_codegen_cache.py
11 files changed, 468 insertions(+), 271 deletions(-)
Approvals:
Michael Smith: Looks good to me, approved
Impala Public Jenkins: Verified
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Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-MessageType: merged
Gerrit-Change-Id: Ic3c1b46bb9018ed0320817141785a3bdc41fa677
Gerrit-Change-Number: 20733
Gerrit-PatchSet: 9
Gerrit-Owner: Yida Wu <[email protected]>
Gerrit-Reviewer: Daniel Becker <[email protected]>
Gerrit-Reviewer: Impala Public Jenkins <[email protected]>
Gerrit-Reviewer: Michael Smith <[email protected]>
Gerrit-Reviewer: Yida Wu <[email protected]>
