Showing posts from August, 2007

Windows Live Writer...Lets see what's Improved.

Hmm.. making this post via Windows Live writer. It automatically detected this blog by just asking for the url (which I gave as! I had to give my Google credentials to it, which I'm still not comfortable with. One glitch. it said it can't upload the image. :( same issue as last time.. not fixed yet.

Linux IPC and Limits

Note: POSIX implementation provides better and cleaner api to IPC compared to System V. Prefer using POSIX api if you are known to be running on 2.6 or later kernel. System V IPC implementation on Linux includes Shared memory, Semaphores and Message queues. There are system imposed limits that are important to keep in mind when developing application/services in Linux. To know the limits use ipcs command. For example on my system: [root@f7 ~]# ipcs -l ------ Shared Memory Limits -------- max number of segments = 4096 max seg size (kbytes) = 32768 max total shared memory (kbytes) = 8388608 min seg size (bytes) = 1 ------ Semaphore Limits -------- max number of arrays = 128 max semaphores per array = 250 max semaphores system wide = 32000 max ops per semop call = 32 semaphore max value = 32767 ------ Messages: Limits -------- max queues system wide = 16 max size of message (bytes) = 8192 default max size of queue (bytes) = 16384 Or via sysctl interface: kernel.shmmni = 4096 kernel.shmal