[OpenMP] Improve performance of ticket lock (x86) #143557
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Ticket lock has a yield operation which degrades performance on larger server machines due to an unconditional pause operation.
hansangbae
reviewed
Jun 10, 2025
|
ping. @hansangbae please review and complete this. Thanks! |
jprotze
approved these changes
Jul 20, 2025
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I think, having the KMP_YIELD macro in the commit message would make it easier to understand the actual problem when just looking at the diff of the patch. After checking the define the issue is clear and the patch LGTM.
#define KMP_YIELD(cond) \
{ \
KMP_CPU_PAUSE(); \
if ((cond) && (KMP_TRY_YIELD)) \
__kmp_yield(); \
}
|
Merged the change with the suggested commit message. |
This was referenced Jul 23, 2025
mahesh-attarde
pushed a commit
to mahesh-attarde/llvm-project
that referenced
this pull request
Jul 28, 2025
Ticket lock has a yield operation (shown below) which degrades
performance on larger server machines due to an unconditional pause
operation.
```
#define KMP_YIELD(cond) \
{ \
KMP_CPU_PAUSE(); \
if ((cond) && (KMP_TRY_YIELD)) \
__kmp_yield(); \
}
```
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Ticket lock has a yield operation (shown below) which degrades performance on larger server machines due to an unconditional pause operation.