Re: posix shared memory

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#48

From: Mindaugas Rasiukevicius
Date: Fri, 29 Mar 2013 15:49

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Hi,

yamt@mwd.biglobe.ne.jp (YAMAMOTO Takashi) wrote:
> i have userland implementation of posix shared memory.
> (attached)
> 
> rmind proposed a kernel implementation while ago.
> http://mail-index.netbsd.org/tech-kern/2009/07/30/msg005599.html
> (thus cc:)
> 
> which way should we go?
> 
> IMO userland implementation is better because:
> 	- simpler
> 	- smaller
> 	- a bug would have less impact
> 	- "locking object in memory" functionality is better to be
> 	  implemented with more generic api like fcntl if necessary

We should go with the userland implementation.  After some though I
basically agree with you that facilities like memory locking can be
implemented with fcntl, mount option tmpfs or whatever.

However, I would say it would be better to create tmpfs partition
for this.  A while ago I came up with practically same code, but
also checking for the fs type:

http://www.netbsd.org/~rmind/shm.c

> 
> YAMAMOTO Takashi

-- 
Mindaugas

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From: Mindaugas Rasiukevicius <rmind@netbsd.org>
Newsgroups: fa.netbsd.tech.kern
Subject: Re: posix shared memory
Date: Fri, 29 Mar 2013 15:49:49 UTC
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Cc: tech-userlevel@netbsd.org, tech-kern@netbsd.org
To: yamt@mwd.biglobe.ne.jp (YAMAMOTO Takashi)
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