Re: [Xen-devel] XenStore difficulties.

[Ewan Mellor <ewan@xxxxxxxxxxxxx>]

On Tue, Nov 14, 2006 at 10:42:16AM +0000, Ewan Mellor wrote:

> On Mon, Nov 13, 2006 at 09:23:52PM -0800, John McCullough wrote:
> 
> > Hello,
> > 
> > I am working on forking hvm domains and I have been using xenstore to
> > send commands to qemu.  I have noticed that occasionally qemu's watch is
> > not read.  I am using the qemu fd handler methods.  I have been trying
> > to duplicate the missed read outside of qemu and the rest of xend, but I
> > haven't been able to.  However, I think I may have discovered a memory
> > leak in lowlevel/xs/xs.c.
> > 
> > I am attaching:
> >    - commandee.c : consumer of "commands"
> >    - commander.py : issuer of commands
> >    - xsblockingchannel.py : com channel for the commander
> > 
> > I am working against a changset from midsummer (11536:041be3f6b38e)
> > since I'm trying to iron out some of my bugs before moving forward in
> > the revisions.
> > 
> > % gcc -o commandee commandee.c /usr/lib/libxenstore.a -lpthread
> > % sudo ./commandee > /dev/null 
> > % time sudo python commander.py > /dev/null #(in separate terminal)
> > Traceback (most recent call last):
> >   File "commander.py", line 9, in ?
> >       xsbc = xsblockingchannel.xsblockingchannel("test")
> >   File "/net/xen/xsstress/xsblockingchannel.py", line 19, in __init__
> >         self.xs.watch(self.path, self)
> >         xen.lowlevel.xs.Error: (12, 'Cannot allocate memory')
> >         Exception xen.lowlevel.xs.Error: (2, 'No such file or
> >         directory') in <bound method xsblockingchannel.__del__ of
> >         <xsblockingchannel.xsblockingchannel instance at 0xb7ce448c>> 
> > ignored
> > 
> > 1.02s user 5.00s system 8% cpu 1:08.61 total
> 
> I can't remember the details, but I have vague recollection of a
> Xenstore-related problem where the error was ENOMEM, but that error was
> misleading.

The problem I was thinking was a misleading ENOSPC, not a misleading ENOMEM
(and we've since fixed the ENOSPC).  It looks like your ENOMEM might be real.

Ewan.

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel