mount error(12): Cannot allocate memory
Refer to the mount.cifs(8) manual page (e.g.man mount.cifs)

After checking the Event Viewer System log, I found the following error:

Source: srv
Event ID: 2017
Level: Error
The server was unable to allocate from the system nonpaged pool because the server reached the configured limit for nonpaged pool allocations.

Some research led me to find this Google Groups discussion about the problem and this Microsoft Technet article discussing the solution (look at the bottom of the page).  Apparently you need to tell Windows that you want to use the machine as a file server and that it should allocate resources accordingly.  Set the following registry key to ’1′:

HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\LargeSystemCache

and set the following registry key to ’3′:

HKLM\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters\Size

After making these changes and restarting, I haven’t seen this issue arise again.  Fixed!

Update (2011/9/16): I had no idea this fix would end up being so popular when I wrote it up.  It is easily the most visited page on this site.  The original Technet article seems to be gone now, but a commenter has pointed me to a text file that contains the same content.  Here is the link: http://www.decuslib.com/decus/vmslt99a/nt/tips.txt

It really would be nice if 64-bit Linux was supported by Google rather than having to find these work-around builds.  Clearly it works for us, what is the holdup?

DISCLAIMER:I have no idea if what I have here is a good idea beyond the fact that my video card is working properly under linux-rt.  My computer froze a couple times with the following setup but I’m not sure if it’s the fix or the fact that linux-rt apparently doesn’t play well with multiple core machines. Or the computer freezy gnomes. Whatever. Use at your own risk.

I’m running Kubuntu 9.04 on AMD64.

While setting up my linux audio recording setup on Kubuntu 9.04 I installed the linux-rt meta-package (which right now points to linux-2.6.28-3-rt) for real time process scheduling.  I was dismayed and not at all surprised that the proprietary nVidia driver for my GeForce 7950  GT did not work immediately when I booted up out of GRUB with the new kernel.  So, I downloaded the latest nVidia driver from http://www.nvidia.com/object/linux_display_amd64_185.18.14.html and tried to install as I have to do every time there is a new linux kernel update by running this with the downloaded script:

$> sudo sh NVIDIA-Linux-x86_64-185.18.14-pkg2.run

The script informs you that it needs to compile the kernel module as usual, but dies saying compilation was unsuccessful. Following the advice of some forum posts I found, I extracted the script into its source tree with:

$> sudo sh NVIDIA-Linux-x86_64-185.18.14-pkg2.run -x

which creates a directory with a script nvidia-installer.sh and the source tree. I ran the installer manually with:

$> cd NVIDIA-Linux-x86_64-185.18.14-pkg2
$> sudo ./nvidia-installer


Compilation fails again at the same step. Inspecting /var/log/nvidia-installer.log tells us:

/home/labadorf/video_drivers/NVIDIA-Linux-x86_64-185.18.14-pkg2/usr/src/nv/os-interface.c:130: error: incompatible types in assignment

After poking around some forums there were some suggestions about replacing some SEMAPHORE code in certain driver source files, but they were for the wrong driver version (177) and didn’t work. Alright, well I have the source for both the kernel and driver, I thought, so let’s see what this incompatible type assignment is. At the end of the day, I traced the error to a couple lines of code earlier in usr/src/nv/os-interface.c. Apparently, the driver is trying to pass some raw_spinlock_t kernel struct to a function that can only accept spinlock_t structs when it detects you’re using a real time kernel. So, I thought a little commenting might do the trick…

Original os-interface.c source:


86 typedef struct os_sema_s
87 {
88 nv_stack_t *sp;
89 struct completion completion;
90 #if defined(CONFIG_PREEMPT_RT)
91 raw_spinlock_t lock;
92 #else
93 spinlock_t lock;
94 #endif
95 S032 count;
96 } os_sema_t;
97


Modified code:

86 typedef struct os_sema_s
87 {
88 nv_stack_t *sp;
89 struct completion completion;
90 //#if defined(CONFIG_PREEMPT_RT)
91 // raw_spinlock_t lock;
92 //#else
93 spinlock_t lock;
94 //#endif
95 S032 count;
96 } os_sema_t;
97


Lo and behold, on recompiling the driver everything works fine. Now, I suppose there may have been a good reason to use the raw version of the struct, but I got all of my audio stuff running with much lower latency AND using both monitors on high resolution (which is really handy since some of these audio apps take up a lot of screen real estate). There are a couple bugs open on this issue so I didn’t feel the need to post anything (though none of the comments there helped with my problem), hopefully someone will figure out what the problem is and fix it soon.

Note: By default the installer replaces whatever driver you have with the new one. You have to unpack the driver source and use the installer manually if you want to use different kernels and not recompile the driver every time. Look at this post and specifically Switcher’s comment 12 for instructions on how to do that.

Like I said, the commenting out I’ve done may be a terrible, terrible idea, but as I know nothing about graphics drivers and even less about kernel building I’m playing the ignorant fool. Good luck.

I’m currently running the currently unreleased Ubuntu Jaunty on virtually all of my machines.  At times, such as when resuming my notebook, I find that my X session has died.  This is not that much of an inconvenience for me—I do most of my work within a screen session that exists as long as the machine stays running, regardless of what X decides to do.  However, services such as ssh-agent must be restarted when creating a new X session and along with this restart comes a new set values for SSH_AGENT_PID and SSH_AUTH_SOCK.  In addition, it is possible that DISPLAY may change as well.

While these variables have changed, the screen sessions values have not been updated.  So when I re-attach to the running screen session and attempt to use ssh, I find that rather than using the running ssh-agent process to cache my passphrase, I am prompted in my terminal to enter the passphrase.  If I were able to use the updated environment variables I could use the ssh-agent process and all would be fine.

As I normally do, I googled for this issue and ran across this solution to the problem.  Rather than reiterate the details presented in this post, I simply show the two zsh functions I’ve written, as they differ sightly from the afore mentioned post:

grabvars()
{
VARS="SSH_AGENT_PID SSH_AUTH_SOCK DISPLAY"
 
#For each variable in $VARS
for x in $(echo $VARS) ; do
eval echo $x=\$$x | sed  's/=/="/
s/$/"/
s/^/export /'
done 1>$VARSLOC
}
 
sourcevars()
{
if [[ -f $VARSLOC ]]; then
source $VARSLOC
fi
}

Note that VARSLOC names the file that the export statements should be written to.

How do I use these two functions?  sourcevars is called every time a new shell is created (I’ve simply added a call to this function in ~/.zshrc).  grabvars is only called when I create or attach to a screen session, so I’ve aliased ‘screen’ to be ‘grabvars; screen’.  So now when I first login and create a new terminal, this terminal has the updated environment vars.  I do a ‘screen -DR session_name’ to attach, which then calls grabvars, the correct values are written to VARSLOC, and my screen session is attached.  If I create a new window in my screen session, the correct variables are now set.  If I want the updated variables in an exsiting window, I simply call ‘sourcevars’.