Hello Dan Burkert, Kudu Jenkins,
I'd like you to reexamine a change. Please visit
http://gerrit.cloudera.org:8080/5166
to look at the new patch set (#3).
Change subject: KUDU-1448. Enable AVX2 bitshuffle at runtime
......................................................................
KUDU-1448. Enable AVX2 bitshuffle at runtime
This uses some trickery when building bitshuffle so that we build it
twice: once with normal flags and a second time with -mavx2. Enabling
AVX2 turns on some faster code paths which have been previously
benchmarked to yield a ~30% end-to-end improvement in some Impala scans.
In order to avoid multiply-defined symbols, the build uses 'objcopy' to
rename the symbols to add a '_avx2' suffix before linking. Then a new
wrapper file uses the 'ifunc' attribute to do runtime resolution of the
correct variant to call.
I'd previously attempted to do this upstream in the bitshuffle library
but it was somewhat difficult as the library makes heavy use of macros,
etc. In that prior attempt, I gave up after many hours of work, whereas
this was comparatively quite simple (only an hour of work!)
This also fixes a bug in the cpuid detection which we inherited
from Chromium. I filed the bug upstream here:
https://bugs.chromium.org/p/chromium/issues/detail?id=667457
I tested on my laptop which has AVX2 and verified that the AVX2 variant
functions were getting called.
Change-Id: Ied8887c0240a649158085676fdd08ab8628bf7d6
---
M src/kudu/cfile/CMakeLists.txt
A src/kudu/cfile/bitshuffle_arch_wrapper.cc
A src/kudu/cfile/bitshuffle_arch_wrapper.h
M src/kudu/cfile/bshuf_block.cc
M src/kudu/cfile/bshuf_block.h
M src/kudu/gutil/cpu.cc
M thirdparty/build-definitions.sh
7 files changed, 178 insertions(+), 12 deletions(-)
git pull ssh://gerrit.cloudera.org:29418/kudu refs/changes/66/5166/3
--
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Gerrit-MessageType: newpatchset
Gerrit-Change-Id: Ied8887c0240a649158085676fdd08ab8628bf7d6
Gerrit-PatchSet: 3
Gerrit-Project: kudu
Gerrit-Branch: master
Gerrit-Owner: Todd Lipcon <[email protected]>
Gerrit-Reviewer: Adar Dembo <[email protected]>
Gerrit-Reviewer: Dan Burkert <[email protected]>
Gerrit-Reviewer: Kudu Jenkins
Gerrit-Reviewer: Tidy Bot
Gerrit-Reviewer: Todd Lipcon <[email protected]>
