From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <49FF08C4.40908@domain.hid> Date: Mon, 04 May 2009 08:24:52 -0700 From: Thomas Lockhart MIME-Version: 1.0 References: <5D63919D95F87E4D9D34FF7748CE2C2A018D48CC@ARVMAIL1.mra.roland-man.biz> <49FDFCC7.6000009@domain.hid> <20090504072304.A7E2483420E8@domain.hid> In-Reply-To: <20090504072304.A7E2483420E8@domain.hid> Content-Type: multipart/alternative; boundary="------------030304040909060501070002" Subject: Re: [Xenomai-help] Some problems with shared memory List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Wolfgang Denk Cc: "xenomai@xenomai.org" This is a multi-part message in MIME format. --------------030304040909060501070002 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable > >> 1.) If I don=B4t page align the size of shared memory (multiple of > >> 4096)... > The restrictions for page allignments affect the addr and offset > paraemters only. To me it seems clear that mmap() in plain Linux and > Xenomai behave differently. Sorry for not having the start of the thread. I'm not sure if it is=20 helpful to note that when I implemented memory mapped "device drivers"=20 for our system I had to align the address and offset to the page size=20 before the call to mmap would succeed. That was with plain Linux and the=20 driver also works with Xenomai. - Tom --=20 Thomas Lockhart Supervisor, Distributed and Real-time Group Instrument Software and Science Data Systems Caltech/JPL --------------030304040909060501070002 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit >>> 1.) If I don´t page align the size of shared memory (multiple of
>>> 4096)...
> The restrictions for page allignments affect the addr and offset
> paraemters only. To me it seems clear that mmap() in plain Linux and
> Xenomai behave differently.

Sorry for not having the start of the thread. I'm not sure if it is helpful to note that when I implemented memory mapped "device drivers" for our system I had to align the address and offset to the page size before the call to mmap would succeed. That was with plain Linux and the driver also works with Xenomai.

- Tom

--
Thomas Lockhart
Supervisor, Distributed and Real-time Group
Instrument Software and Science Data Systems
Caltech/JPL

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