一. 原因

发生在Linux Ubuntu上，运行或编译占用内存巨大的大软件大项目的过程中可能会出现 errno12 :    Cannot allocate memory。

原因应为内存不足，可以尝试增加内存条，可以尝试创建或增加swap的空间。如果算法是自己编写的

我的机器用的是swapfile，而不是独立的swap分区，所以修改起来比较方便。

 

二 . 解决

    1.观察

执行命令并观察swap空间是否存在和大小：

$free -h

$swapon -s

   2. 删除swapfile

-------------------------------------------------------------------------------------------------------------------------下面是删除swapfile

如果已经存在swapfile(例如：/swapfile),那么先执行如下三条删除之。

#swapoff  /swapfile      #unmount swap文件

*******下面这行可以不执行，因为后面创建/swapfile时还要再加入这一行

#vim /etc/fstab

编辑删除开头为swap的那一行

#rm -rf /swapfile

再执行free和swapon -s ,检查是否依然存在swap空间

---------------------------------------------------------------------------------------删除完毕----------------------------------------------------

     3.创建更大的swapfile

---------------------------------------------------------------------------------------------------------------------------下面是创建swapfile

三步创建：

一步.  创建/swapfile：

#dd if/dev/zero of=/swapfile bs=1M count=16384

其中，16384=16×1024，即创建了一个16G的swapfile。

if=指定输入文件名
of=指定输出文件名
bs=bytes：同时设置读入/输出的块大小为bytes个字节
count=blocks：此为块大小，等于以bs为单位指定的空间。
--------------------- 

二步.  changemode

chmode 0600 /swapfile

三步.  格式化

#mkswap  /swapfile

三步.  配置文件，PC启动时随之挂载swap空间

#vim /etc/fstab

在最末增加新的一行

/swapfile          swap       swap     no       0       0      

四步.   挂载启动swap空间

#swapon    /swapfile

----------------------------------------------------------------------------------创建完毕-----------------
可以执行    free -h     swapon -s，看看swap空间大小

 

重新启动电脑，并执行free和swapon是否依然。

重新编译自己的项目，看看是否解决了OpenJDK的errno=12的问题。

 

 

补充信息：

其中errno对应的错误指示信息，参考  <errno.h> 

errno0 :     Success

errno1 :     Operation not permitted

errno2 :     No such file or directory

errno3 :     No such process

errno4 :     Interrupted system call

errno5 :     Input/output error

errno6 :     No such device or address

errno7 :     Argument list too long

errno8 :     Exec format error

errno9 :     Bad file descriptor

errno10 :    No child processes

errno11 :    Resource temporarily unavailable

errno12 :    Cannot allocate memory

errno13 :    Permission denied

errno14 :    Bad address

errno15 :    Block device required

errno16 :    Device or resource busy

errno17 :    File exists

errno18 :    Invalid cross-device link

errno19 :    No such device

errno20 :    Not a directory

errno21 :    Is a directory

errno22 :    Invalid argument

errno23 :    Too many open files in system

errno24 :    Too many open files

errno25 :    Inappropriate ioctl for device

errno26 :    Text file busy

errno27 :    File too large

errno28 :    No space left on device

errno29 :    Illegal seek

errno30 :    Read-only file system

errno31 :    Too many links

errno32 :    Broken pipe

errno33 :    Numerical argument out of domain

errno34 :    Numerical result out of range

errno35 :    Resource deadlock avoided

errno36 :    File name too long

errno37 :    No locks available

errno38 :    Function not implemented

errno39 :    Directory not empty

errno40 :    Too many levels of symbolic links

errno41 :    Unknown error 41

errno42 :    No message of desired type

errno43 :    Identifier removed

errno44 :    Channel number out of range

errno45 :    Level 2 not synchronized

errno46 :    Level 3 halted

errno47 :    Level 3 reset

errno48 :    Link number out of range

errno49 :    Protocol driver not attached

errno50 :    No CSI structure available

errno51 :    Level 2 halted

errno52 :    Invalid exchange

errno53 :    Invalid request descriptor

errno54 :    Exchange full

errno55 :    No anode

errno56 :    Invalid request code

errno57 :    Invalid slot

errno58 :    Unknown error 58

errno59 :    Bad font file format

errno60 :    Device not a stream

errno61 :    No data available

errno62 :    Timer expired

errno63 :    Out of streams resources

errno64 :    Machine is not on the network

errno65 :    Package not installed

errno66 :    Object is remote

errno67 :    Link has been severed

errno68 :    Advertise error

errno69 :    Srmount error

errno70 :    Communication error on send

errno71 :    Protocol error

errno72 :    Multihop attempted

errno73 :    RFS specific error

errno74 :    Bad message

errno75 :    Value too large for defined datatype

errno76 :    Name not unique on network

errno77 :    File descriptor in bad state

errno78 :    Remote address changed

errno79 :    Can not access a needed sharedlibrary

errno80 :    Accessing a corrupted sharedlibrary

errno81 :    .lib section in a.out corrupted

errno82 :    Attempting to link in too manyshared libraries

errno83 :    Cannot exec a shared librarydirectly

errno84 :    Invalid or incomplete multibyte orwide character

errno85 :    Interrupted system call should berestarted

errno86 :    Streams pipe error

errno87 :    Too many users

errno88 :    Socket operation on non-socket

errno89 :    Destinationaddress required

errno90 :    Message too long

errno91 :    Protocol wrong type for socket

errno92 :    Protocol not available

errno93 :    Protocol not supported

errno94 :    Socket type not supported

errno95 :    Operation not supported

errno96 :    Protocol family not supported

errno97 :    Address family not supported byprotocol

errno98 :    Address already in use

errno99 :    Cannot assign requested address

errno100 :   Network is down

errno101 :   Network is unreachable

errno102 :   Network dropped connection onreset

errno103 :   Software caused connection abort

errno104 :   Connection reset by peer

errno105 :   No buffer space available

errno106 :   Transport endpoint is alreadyconnected

errno107 :   Transport endpoint is notconnected

errno108 :   Cannot send after transportendpoint shutdown

errno109 :   Too many references: cannot splice

errno110 :   Connection timed out

errno111 :   Connection refused

errno112 :   Host is down

errno113 :   No route to host

errno114 :   Operation already in progress

errno115 :   Operation now in progress

errno116 :   Stale NFS file handle

errno117 :   Structure needs cleaning

errno118 :   Not a XENIX named type file

errno119 :   No XENIX semaphores available

errno120 :   Is a named type file

errno121 :   Remote I/O error

errno122 :   Disk quota exceeded

errno123 :   No medium found

errno124 :   Wrong medium type

errno125 :   Operation canceled

errno126 :   Required key not available

errno127 :   Key has expired

errno128 :   Key has been revoked

errno129 :   Key was rejected by service

errno130 :   Owner died

errno131 :   State not recoverable

errno132 :   Operation not possible due toRF-kill

errno133 :   Unknown error 133

errno134 :   Unknown error 134

errno135 :   Unknown error 135

errno136 :   Unknown error 136

errno137 :   Unknown error 137

errno138 :   Unknown error 138

errno139 :   Unknown error 139
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