Yeah, humongous allocation savings is a bigger advantage to have as compared to some amount of fragmentation which will come with larger 32MB.
Would love to hear more comments. On Thu, Feb 2, 2017 at 9:50 PM, yu.zh...@oracle.com <yu.zh...@oracle.com> wrote: > Hi, Amit, > > IMO, there is no one size fits all. > > Some considerations about the bigger region size: > > Reduce the humongous objects. The humongous objects are allocated in old > gen. If they can not be collected during young gc, they can fill up the old > gen quickly without marking or full gc. > > Less remember set to keep track of. > > Bigger TLAB. This could be good or bad. With bigger tlab, threads need > less refill trip, but may waste more tlab space. It depends on the objects > size. > > Possible bigger waste due to humongous objects (depends on the size of the > objects) > > Possible end of region waste for allocation. > > Maybe others have more comments. > > Thanks > > Jenny > > On 02/01/2017 05:54 AM, Amit Balode wrote: > > Hello, We have multiple applications running in production where > predicting size of the runtime object is kinda tough and random. It could > vary from 1KB to 25MB for different applications. To not have too many > lingering configs for different applications, I am trying to come up with > standard set of configs which could be applicable to all applications. Some > applications do not exceed 10KB object size, so I could definitely keep 2MB > as region size for them. But I am wondering what would be disadvantage of > setting all applications to 32MB region size regardless of how small the > object is? > > Is it that fragmentation issues will happen more if you have less regions? > If so, will the fragmentation issue happen only during humongous > allocations? > In term of performance, will selection of size change anything? > > -- > Thanks & Regards, > Amit.Balode > > > > _______________________________________________ > hotspot-gc-use mailing > listhotspot-gc-...@openjdk.java.nethttp://mail.openjdk.java.net/mailman/listinfo/hotspot-gc-use > > > -- Thanks & Regards, Amit.Balode
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