Re: oops, 2.4.26 and jfs

[Marcelo Tosatti <marcelo.tosatti@cyclades.com>]

 On Fri, May 28, 2004 at 06:16:22PM -0700, Chris Stromsoe wrote:
> On Fri, 28 May 2004, Dave Kleikamp wrote:
> 
> > On Fri, 2004-05-28 at 15:15, Chris Stromsoe wrote:
> > > This morning during a cron run while doing a find across /, I got the
> > > following oops.
> >
> > The oops is fixed in 2.4.27-pre3 with the patch:
> > http://linux.bkbits.net:8080/linux-2.4/cset@1.1359.20.3
> >
> > jfs still may give you problems if 0-order allocations are failing, but
> > it's not supposed to trap.
> 
> Thanks, patch applied.
> 
> 
> Aside from that:
> 
> > May 26 06:28:10 begonia kernel: __alloc_pages: 0-order allocation failed
> > (gfp=0x1f0/0)
> 
> I'm curious about why 0-order allocations would fail.  From everything
> I've read (google searching for the error message), that indicates an out
> of memory condition, which shouldn't be the case.
> 
> The box in question has 4Gb of physical ram (512Mb is used as tmpfs) and
> 9Gb of swap.  When the oops happened, no swap was in use.  Physical ram
> was pretty much filled, but no swap at all.  OOM_KILLER is not enabled.

Hi Chris, 

This seems to be a normal allocation (which can wait), it really
looks the system was out of memory. 

Can you stick a call to show_free_areas() in mm/page_alloc.c after 

        printk(KERN_NOTICE "__alloc_pages: %u-order allocation failed (gfp=0x%x/%i)\n",
               order, gfp_mask, !!(current->flags & PF_MEMALLOC));

so we know the state of the memory areas when it happens again.

Also turn on /proc/sys/vm/vm_gfp_debug.

> There's nothing especially exotic in the box.  It does a lot of network
> traffic (eepro100) and a lot of disk traffic (aic7xxx).  The morning cron
> jobs had just kicked off.  Two of them do "find /"  -- I believe that the
> second one was running when it happened.