Hugetlbfs and Shared Memory Post: 302424606

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Operating Systems Linux Hugetlbfs and Shared Memory Post 302424606 by ms_farenheit on Tuesday 25th of May 2010 10:51:18 PM

05-25-2010

Registered User

Hugetlbfs and Shared Memory

I am trying to add support for hugepages into an existing application. I have done a lot of online research, but I still have a few questions that I haven't been able get answers to. Hopefully someone here can help!

(1) My application requires that all mapped memory segments be shared. The existing application, which does not use hugepages, uses shm_open() and mmap() to map the shared memory. Since shm_open() automatically maps into the /dev/shm filepath and hugepages must be mapped into the mount filepath (/mnt on my system), it seems that I cannot use shm_open() for hugepages. Is this correct?

(2) If I cannot use shm_open() for hugepages, is there any way to use open() and mmap() and still get shared memory? Are objects mapped to the hugepage mount filepath shared or can they be?

(3) If I use open() instead of shm_open() but use the shared memory filepath (/dev/shm) does that make it shared?

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LEARN ABOUT LINUX

dpkg-preconfigure

DPKG-PRECONFIGURE(8)						      Debconf						      DPKG-PRECONFIGURE(8)

NAME

       dpkg-preconfigure - let packages ask questions prior to their installation

SYNOPSIS

	dpkg-preconfigure [options] package.deb

	dpkg-preconfigure --apt

DESCRIPTION

       dpkg-preconfigure lets packages ask questions before they are installed.  It operates on a set of debian packages, and all packages that
       use debconf will have their config script run so they can examine the system and ask questions.

OPTIONS

       -ftype, --frontend=type
	   Select the frontend to use.

       -pvalue, --priority=value
	   Set the lowest priority of questions you are interested in. Any questions with a priority below the selected priority will be ignored
	   and their default answers will be used.

       --terse
	   Enables terse output mode. This affects only some frontends.

       --apt
	   Run in apt mode. It will expect to read a set of package filenames from stdin, rather than getting them as parameters. Typically this
	   is used to make apt run dpkg-preconfigure on all packages before they are installed.  To do this, add something like this to
	   /etc/apt/apt.conf:

	    // Pre-configure all packages before
	    // they are installed.
	    DPkg::Pre-Install-Pkgs {
		   "dpkg-preconfigure --apt --priority=low";
	    };

       -h, --help
	   Display usage help.

SEE ALSO

       debconf(7)

AUTHOR

       Joey Hess <joeyh@debian.org>

								    2011-06-22						      DPKG-PRECONFIGURE(8)

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