Re: bcache: register_cache() error opening sdh2: cannot allocate memory => BUG NULL pointer

[Marc MERLIN <marc@merlins.org>]

On Thu, Feb 25, 2016 at 11:30:05PM +0000, Eric Wheeler wrote:
> On Thu, 25 Feb 2016, Marc MERLIN wrote:
> 
> > On Thu, Feb 25, 2016 at 07:29:36AM +0000, Eric Wheeler wrote:
> > > Try this patch.  It adds some error handling:
> > 
> > Thanks, applied. I'll report back if I get output from it.
> > 
> > I think one reason I'm having problem on that server is that I run
> > zoneminder which requires a lot of shared memory:
> > kernel.shmall = 234217728
> > kernel.shmmax = 234217728
> > 
> > Is there a chance that's putting memory pressure in the wrong memory
> > pool on the system?
> 
> Perhaps, though I'm thinking your shm values are far too large.  Those are 
> in units of pages, so with 4k pages you have set almost 900GB of shared 
> memory limit.  Does this machine have 1TB of ram?

Indeed, no.

> I like to set vm.min_free_kbytes = 262144 on my machines.  Its <1% on our 
> systems and we never have memory issues, even with high memory pressure 
> and zram for swap.

Very good catch. I'll fix that.
I use zoneminder which requires stupid amounts of shared memory, but not 1TB
:)

Thanks,
Marc
-- 
"A mouse is a device used to point at the xterm you want to type in" - A.S.R.
Microsoft is to operating systems ....
                                      .... what McDonalds is to gourmet cooking
Home page: http://marc.merlins.org/