Bugs Found In Linux
|Name||Description||Kernel version||Impacted applications||Maximum measured performance impact|
|Group Imbalance||When launching multiple applications with different thread counts, some CPUs are idle while others are overloaded||2.6.38+||All||13X|
|Scheduling Construction||No load balancing between nodes that are 2-hops apart||3.9+||All||27X|
|Overload-on-Wakeup||Threads wake up on overloaded cores while some other cores are idle.||2.6.32+||Applications that sleep or wait||22%|
|Missing Scheduling Domains||The load is not balanced between NUMA nodes||3.19+||All||138X|
We’ve known forever that Linux is not perfect but it works very well. TFA quoted above points out several bugs in the scheduler which lets us down on heavily loaded systems with many threads. Lets see if this fix can be introduced into the mainstream kernel.
UPDATE – This could actually go somewhere. Peter Zijlstra has nibbled…