configure: don't reduce parsers' optimization level to 1 in release #12460
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Refs #12445 |
michoecho
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avikivity
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Jan 5, 2023
| @@ -2015,7 +2015,8 @@ def query_seastar_flags(pc_file, link_static_cxx=False): | |||
| f.write('build {}: cxx.{} {} || {}\n'.format(obj, mode, cc, ' '.join(serializers))) | |||
| if cc.endswith('Parser.cpp'): | |||
| # Unoptimized parsers end up using huge amounts of stack space and overflowing their stack | |||
| flags = '-O1' | |||
| flags = '-O1' if modes[mode]['optimization-level'] in ['0', 'g', 's'] else '' | |||
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Looks good. Please file an issue. I normally don't like backporting performance patches, but this one can have such random effects (varying across point releases) that it's better to backport it.
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The line modified in this patch was supposed to increase the optimization levels of parsers in debug mode to 1, because they were too slow otherwise. But as a side effect, it also reduced the optimization level in release mode to 1. This is not a problem for the CQL frontend, because statement preparation is not performance-sensitive, but it is a serious performance problem for Alternator, where it lies in the hot path. Fix this by only applying the -O1 to debug modes. Fixes scylladb#12463
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BTW, I just learned that since Clang 13 |
avikivity
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The line modified in this patch was supposed to increase the optimization levels of parsers in debug mode to 1, because they were too slow otherwise. But as a side effect, it also reduced the optimization level in release mode to 1. This is not a problem for the CQL frontend, because statement preparation is not performance-sensitive, but it is a serious performance problem for Alternator, where it lies in the hot path. Fix this by only applying the -O1 to debug modes. Fixes #12463 Closes #12460 (cherry picked from commit 08b3a9c)
avikivity
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Jan 7, 2023
The line modified in this patch was supposed to increase the optimization levels of parsers in debug mode to 1, because they were too slow otherwise. But as a side effect, it also reduced the optimization level in release mode to 1. This is not a problem for the CQL frontend, because statement preparation is not performance-sensitive, but it is a serious performance problem for Alternator, where it lies in the hot path. Fix this by only applying the -O1 to debug modes. Fixes #12463 Closes #12460 (cherry picked from commit 08b3a9c)
fgelcer
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Jan 9, 2023
The line modified in this patch was supposed to increase the optimization levels of parsers in debug mode to 1, because they were too slow otherwise. But as a side effect, it also reduced the optimization level in release mode to 1. This is not a problem for the CQL frontend, because statement preparation is not performance-sensitive, but it is a serious performance problem for Alternator, where it lies in the hot path. Fix this by only applying the -O1 to debug modes. Fixes scylladb#12463 Closes scylladb#12460 (cherry picked from commit 08b3a9c)
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The line modified in this patch was supposed to increase the optimization levels of parsers in debug mode to 1, because they were too slow otherwise. But as a side effect, it also reduced the optimization level in release mode to 1. This is not a problem for the CQL frontend, because statement preparation is not performance-sensitive, but it is a serious performance problem for Alternator, where it lies in the hot path.
Fix this by only applying the -O1 to debug modes.
Fixes #12463