From owner-freebsd-hackers  Tue Jun 18  7:38:23 2002
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Date: Tue, 18 Jun 2002 07:37:56 -0700 (PDT)
From: joy ganguly <ugly_kid_joy@yahoo.co.in>
Subject: mmap and MAP_NOSYNC
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Hi all,

Hi,

I want to use mmap as a means of doing IPC between
unrelated processes. I do *not* want the data to hit
the disk. So this is what I do :-

fd = open(file, O_RDWR);
p = mmap(fd, MAP_NOSYNC | MAP_SHARED);
mlock(p, len);

/* Whack around with shmem */


Now my question is , once I have wired the shared
memory region, is it possible that the data still hits
the disk ? One would think the pager will not look at
wired pages. Is that correct ?

Thanks in advance.

Joy



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