| 高优先级:-XX:NewSize -XX:MaxNewSize | 
|---|
| 设置新生代初始值,最大值 | 
| 中优先级:-Xmn(默认等效 -Xmn=-XX:NewSize=-XX:MaxNewSize=?) | 
| 设置新生代初始值 | 
| -XX:NewRatio | 
| 设置老年代和新生代的比例; 例如: -XX:NewRatio = 4→ 新生代 :老年代 = 1:4 ,即新生代占 1/5,老年代占 4/5 | 

| 启动参数 | 
|---|
| -Xms60m -Xmx80m -Xmn30m -XX:NewSize=20m -XX:MaxNewSize=40m-XX:NewRatio=5 -XX:+PrintCommandLineFlags -Xlog:gc* | 
| 启动日志 | 
| -XX:ConcGCThreads=3 -XX:G1ConcRefinementThreads=13 -XX:GCDrainStackTargetSize=64 -XX:InitialHeapSize=62914560-XX:MarkStackSize=4194304-XX:MaxHeapSize=83886080-XX:MaxNewSize=41943040-XX:MinHeapSize=62914560 -XX:NewRatio=5-XX:NewSize=20971520-XX:+PrintCommandLineFlags -XX:ReservedCodeCacheSize=251658240 -XX:+SegmentedCodeCache -XX:+UseCompressedClassPointers -XX:+UseCompressedOops -XX:+UseG1GC -XX:-UseLargePagesIndividualAllocation | 
https://blog.csdn.net/weixin_44663675/article/details/107089808












![[元带你学: eMMC协议 24] eMMC Packed Command CMD23读(Read) 写(write) 操作详解](https://img-blog.csdnimg.cn/img_convert/262abfa94e2b5642120b21810384ce4b.png)






