Comment 12 for bug 785394

@apw

After our meeting at UDS-P, you suggested to change the following in /etc/initramfs/initramfs.conf :

#
# MODULES: [ most | netboot | dep | list ]
#
# most - Add most filesystem and all harddrive drivers.
#
# dep - Try and guess which modules to load.
#
# netboot - Add the base modules, network modules, but skip block devices.
#
# list - Only include modules from the 'additional modules' list
#

MODULES=dep

from MODULES=most and to rebuild the initramfs

I have tested this and I still see the OOM killer kicking in while the kexec booted kernel is trying to start.

One thing that I noticed is that the memory information displayed while the OOM killer is active is the following :
[ 2.810045] active_anon:5339 inactive_anon:33 isolated_anon:0
[ 2.810046] active_file:0 inactive_file:0 isolated_file:0
[ 2.810046] unevictable:1635 dirty:0 writeback:0 unstable:0
[ 2.810047] free:280 slab_reclaimable:1007 slab_unreclaimable:1363
[ 2.810048] mapped:428 shmem:40 pagetables:727 bounce:0
[ 2.813342] Node 0 DMA free:208kB min:4kB low:4kB high:4kB active_anon:328kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictabl
e:0kB isolated(anon):0kB isolated(file):0kB present:320kB mlocked:0kB dirty:0kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:0kB slab_u
nreclaimable:8kB kernel_stack:0kB pagetables:0kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? yes
[ 2.817647] lowmem_reserve[]: 0 51 51 51
[ 2.818158] Node 0 DMA32 free:912kB min:912kB low:1140kB high:1368kB active_anon:21028kB inactive_anon:132kB active_file:0kB inactive_file:
0kB unevictable:6540kB isolated(anon):0kB isolated(file):0kB present:52780kB mlocked:0kB dirty:0kB writeback:0kB mapped:1712kB shmem:160kB sla
b_reclaimable:4028kB slab_unreclaimable:5444kB kernel_stack:776kB pagetables:2908kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0
all_unreclaimable? yes
[ 2.823024] lowmem_reserve[]: 0 0 0 0
[ 2.823937] Node 0 DMA: 0*4kB 0*8kB 1*16kB 0*32kB 1*64kB 1*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 208kB
[ 2.826354] Node 0 DMA32: 3*4kB 0*8kB 0*16kB 0*32kB 0*64kB 1*128kB 1*256kB 1*512kB 0*1024kB 0*2048kB 0*4096kB = 908kB
[ 2.828162] 1675 total pagecache pages
[ 2.828597] 0 pages in swap cache
[ 2.828978] Swap cache stats: add 0, delete 0, find 0/0
[ 2.829585] Free swap = 0kB
[ 2.829919] Total swap = 0kB
[ 2.831199] 61419 pages RAM
[ 2.831580] 49505 pages reserved
[ 2.831957] 7209 pages shared
[ 2.832340] 11055 pages non-shared

There are 49505 reserved pages, compared with only 22984 pages on the running kernel when the VM is booted.

Of course, this issue goes away if the system/VM memory goes above 2G but this is still an issue with smaller amount of memory.