Re: [Crash-utility] "zero-size memory allocation!" is back for Linux 3.1
On Wed, 2012-01-18 at 09:35 -0500, Dave Anderson wrote:
> > > Which causes this in crash/memory.c:vm_init()
> > >
ARRAY_LENGTH_INIT(vt->kmem_cache_len_nodes, NULL,
> > "kmem_cache.nodelists", NULL, 0);
> > > to set vt->kmem_cache_len_nodes to 0, and leads
to the initialization
> > failure when max_cpudata_limit calls getbuf with a size of 0.
> > > Got a fix in the works yet?
> > > Thanks,
> > Bob Montgomery
> No, afraid not. Fedora uses slub instead of slab, so I
haven't
> noticed it. I wonder why kmem_cache_downsize() doesn't recalculate
> vt->kmem_cache_len_nodes based upon "nr_node_ids"?:
> if (buffer_size < SIZE(kmem_cache_s)) {
> if
(kernel_symbol_exists("nr_node_ids")) {
> get_symbol_data("nr_node_ids", sizeof(int),
> &nr_node_ids);
> vt->kmem_cache_len_nodes = nr_node_ids;
> } else
> vt->kmem_cache_len_nodes = 1;
> Dave
This code is skipped because the buffer_size test is no longer true.
Also references to the nodeslist array are bad because it got changed
from an array to a pointer to an external array.
I have a fix and have tested it to give the same results on a *pre-3.1*
CONFIG_SLAB kernel (compared 6.0.2 to 6.0.2-fix on a 2.6.32 base), but
will now work on trying to verify that it's telling the truth about my
CONFIG_SLAB 3.1 kernel.
More later,
Bob Montgomery