Re: posix shared memory

["James K. Lowden" <jklowden%schemamania.org@localhost>]

On Fri, 29 Mar 2013 15:48:49 +0000
Mindaugas Rasiukevicius <rmind%netbsd.org@localhost> wrote:

> We should go with the userland implementation.  

Indeed.  Until today I'd never heard of "Posix shared memory".  Having
read Takashi's code and the Linux documentation, I have to wonder why
it's not just called "open/close wrappers for use with mmap".  

> However, I would say it would be better to create tmpfs partition
> for this.  

It is the user's option to mount tmpfs at /var/shm, right?  

I would think, though, that tmpfs must impose some overhead relative to
ordinary shared memory i.e. shmget.  Another way to gain efficiency
would be to ensure that mmap uses MAP_ANON for descriptors
opened with shm_open.  

--jkl