Dne 10.6.2012 22:16, Simon Baatz napsal(a):

Hi,

[cross posted to linux-lvm, because I think it is a lvm problem]

On Wed, May 30, 2012 at 03:06:23PM -0300, Thiago Jung Bauermann wrote:

quoted

I have just upgraded my Dreamplug to the 3.4 kernel, and when creating
an LVM snapshot volume, I see errors for which I didn't find any report
yet:

# lvcreate -s -L 80M -n root-fsck-snapshot marv2-vg/root
   ffff0000-ffff1000 r-xp 00000000 00:00 0          [vectors]: mlock failed: Cannot allocate memory
   ffff0000-ffff1000 r-xp 00000000 00:00 0          [vectors]: mlock failed: Cannot allocate memory
   ffff0000-ffff1000 r-xp 00000000 00:00 0          [vectors]: munlock failed: Cannot allocate memory
   ffff0000-ffff1000 r-xp 00000000 00:00 0          [vectors]: mlock failed: Cannot allocate memory
   ffff0000-ffff1000 r-xp 00000000 00:00 0          [vectors]: mlock failed: Cannot allocate memory
   ffff0000-ffff1000 r-xp 00000000 00:00 0          [vectors]: munlock failed: Cannot allocate memory
   Logical volume "root-fsck-snapshot" created

Ironically, the main reason I upgraded the kernel from 3.0.0 was to get

I see similar errors on an IB-NAS6210 box. Apparently, lvm2 tries to
mlock/munlock all readable maps it finds in "proc/self/maps", i.e
also the "[vectors]" page.  Between 3.0 and 3.4 there has been the
change f9d4861f "ARM: 7294/1: vectors: use gate_vma for vectors user
mapping", which might have changed the behaviour when mlocking
vectors.

In LVM2, there is a list in lib/mm/memlock.c of maps to ignore:

/* list of maps, that are unconditionaly ignored */
static const char * const _ignore_maps[] = {
     "[vdso]",
     "[vsyscall]",
};

"[vdso]" seem to be based on gate_vma as well. Thus, I think
"[vectors]" needs to be added to this list.

Opps - missed multilist posting - so again with all copies...

Yep, looks like simple patch to add.
Is there any other area which is missing ?

Zdenek