7.3-STABLE and Linux version of SIMetrix

[Alexander Leidinger]

Quoting Andre Albsmeier <Andre.Albsmeier at siemens.com> (from Thu, 6 Jan  
2011 11:40:57 +0100):

> On Thu, 06-Jan-2011 at 09:01:30 +0100, Alexander Leidinger wrote:
>> Quoting Andre Albsmeier <Andre.Albsmeier at siemens.com> (from Wed, 5 Jan
>> 2011 20:19:15 +0100):
>>
>> > Got it running... A short explanation:
>> >
>> > Linux' shm_open() fails because it wants to find some funky shmfs
>> > to construct the full pathname. It starts to search at the default
>> > mountpoint which is /dev/shm. If this fails it runs through fstab
>> > and searches for shmfs and tmpfs. Whatever it finds will be
>> > statfs()'ed to be checked for Linux' fs magic for shmfs (0x01021994).
>>
>> What does it expect as a filesystem type if it does not find shmfs in
>> fstab but tmpfs? If it does not find tmpfs, will it try /tmp anyway
>> (but check for some fstype magic)?
>
> It searches for every mount which is of type tmpfs or shm.
> Whatever it finds must have the fs magic SHMFS_SUPER_MAGIC
> (0x01021994). It's in sysdeps/unix/sysv/linux/shm_open.c:
>
> ------------------------- snip -------------------
>
>   /* Now read the entries.  */
>   while ((mp = __getmntent_r (fp, &resmem, buf, sizeof buf)) != NULL)
>     /* The original name is "shm" but this got changed in early Linux
>        2.4.x to "tmpfs".  */

This looks like it is creating real files there, and the tmpfs thing  
shall make sure it is empty after a reboot. That's just an assumption...

Do you have some temporary files in the location your /dev/shm points  
to during running the linux application which needs it (I do not  
expect that our implementation creates them, but as I haven't looked  
at the code yet, this is something to be verified)?

Bye,
Alexander.

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