Bug#111594: add pading to solve false sharing problem #493
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Signed-off-by: Teresaliu changyan.liu@intel.com
Signed-off-by: Lin Yang lin.a.yang@intel.com
Description
When using sysbench to benchmark mysql's performance, we found MySQL has some scalability issues as the the number of threads increase in select random ranges/points senarios; more details is there: https://bugs.mysql.com/bug.php?id=111594
After investigation, we located that this problem is a
false sharingproblem, and this kind cacheline contention problem could be reduced by adding codepadingto separate variables in the one cacheline.Conclusion
After adding pading, the benchmark results and the performance improvement ratio are as shown in the figure below：
