Reputation: 1150
I did search this issue on net but could not find a possible solution or explanation.
We have a CentOS 6 VM with 8 GB RAM, 64 bit, Open JDK 1.8. We are trying to run a Java program with -Xmx6000M.
It just crashes on start with following out of memory error:
native memory allocation (malloc) failed to allocate 32756 bytes for ChunkPool::allocate
It just executes starting few lines of the code (no much memory allocation there <500MB) and crashes continously.
Interesting thing is if I change -Xmx to 3000M, it starts working fine and my program is up and all good.
As per my understanding, Xmx denotes maximum heap memory that a JVM can go upto and it is on demand allocation. So, I am unable to get how is it causing the crash even JVM did not reach 1 GB of heap and how reducing Xmx is solving it?
I know if OS is unable to provide the required memory, JVM can crash with OOM but here OS has always more than 3 GB of free memory.
Please advice.
Output of /etc/proc/meminfo is:
MemTotal: 8061104 kB
MemFree: 4905068 kB
Buffers: 172920 kB
Cached: 1828412 kB
SwapCached: 0 kB
Active: 1751828 kB
Inactive: 1129956 kB
Active(anon): 872840 kB
Inactive(anon): 58348 kB
Active(file): 878988 kB
Inactive(file): 1071608 kB
Unevictable: 0 kB
Mlocked: 0 kB
SwapTotal: 4194300 kB
SwapFree: 4194300 kB
Dirty: 24 kB
Writeback: 0 kB
AnonPages: 880488 kB
Mapped: 334788 kB
Shmem: 50740 kB
Slab: 133388 kB
SReclaimable: 92196 kB
SUnreclaim: 41192 kB
KernelStack: 6880 kB
PageTables: 23236 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 8224852 kB
Committed_AS: 1534484 kB
VmallocTotal: 34359738367 kB
VmallocUsed: 185660 kB
VmallocChunk: 34359545792 kB
HardwareCorrupted: 0 kB
AnonHugePages: 493568 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kB
DirectMap4k: 251904 kB
DirectMap2M: 7088128 kB
DirectMap1G: 1048576 kB
UPDATE One thing we noticed that swap memory on this OS is not working, it always show 0 KB in used. Can this be the potential reason for OOM?
Upvotes: 0
Views: 3628
Reputation: 145
Java HotSpot VM is split between 3 memory spaces (Java Heap, PermGen, C-Heap). For a 32-bit VM, all these memory spaces compete between each other for memory. Increasing the Java Heap space (with -Xmx) will further reduce capacity of the C-Heap and reserve more memory from the OS.
This is also why reducing -Xmx to 3000M as you did makes your programm work fine.
For more details, see https://javaeesupportpatterns.blogspot.com/2012/03/outofmemoryerror-out-of-swap-space.html
Upvotes: 1