linux的一些系统限制
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1. 关于POSIX机制的消息队列mq:
This filesystem can be mounted (by the superuser) using the following commands: # mkdir /dev/mqueue # mount -t mqueue none /dev/mqueue The sticky bit is automatically enabled on the mount directory. * Before Linux 2.6.28, the upper limit is INT_MAX. * From Linux 2.6.28 to 3.4, the limit is 1,048,576. * Since Linux 3.5, the limit is 16,777,216 (HARD_MSGSIZEMAX). The msgsize_max limit is ignored for privileged process (CAP_SYS_RESOURCE), but, since Linux 3.5, the HARD_MSGSIZEMAX ceiling is enforced for privileged processes. /proc/sys/fs/mqueue/queues_max This file can be used to view and change the system-wide limit on the number of message queues that can be created. The default value for queues_max is 256. No ceiling is imposed on the queues_max limit; privileged processes (CAP_SYS_RESOURCE) can exceed the limit (but see BUGS).
(1)attr.mq_maxmsg 不能超过文件 /proc/sys/fs/mqueue/msg_max 中的数值,我的机器上面是10。
(2)attr.mq_msgsize不能超过 /proc/sys/fs/mqueue/msgsize_max 的数值。
(3)消息队列名称前面必须加上斜杆。
详细请参考:命令“man mq_overview”
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