Tim Armstrong has posted comments on this change. Change subject: IMPALA-2680: faster memory copy ......................................................................
Patch Set 10: I ran an end-to-end benchmark query does a lot of small memcpys (on non-codegened paths, some of which will be codegened). select distinct * from tpch_parquet.lineitem limit 5 In the baseline version it spends ~4.9% of CPU time in __memcpy_avx_unaligned, with this patch it spends ~4.2% in _ZN6impala7MemUtil6memcpyEPvPKvm.avx2 and ~0.7% in __memcpy_avx_unaligned. So it doesn't seem like there's any gain. Change in end-to-end query time and operator cpu time was within variance. I'm not sure if we have any end-to-end workloads that do large memcpys: i suspect those would be where we see improvement. -- To view, visit http://gerrit.cloudera.org:8080/1686 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: comment Gerrit-Change-Id: I7f6c046d966883aa66f26d58bee92c427f973e67 Gerrit-PatchSet: 10 Gerrit-Project: Impala Gerrit-Branch: cdh5-trunk Gerrit-Owner: Zuo Wang <[email protected]> Gerrit-Reviewer: Dan Hecht <[email protected]> Gerrit-Reviewer: Marcel Kornacker <[email protected]> Gerrit-Reviewer: Mostafa Mokhtar <[email protected]> Gerrit-Reviewer: Tim Armstrong <[email protected]> Gerrit-Reviewer: Zuo Wang <[email protected]> Gerrit-HasComments: No
