Commits
Mel Gorman committed b4911ea2bcf
mm: initialise per_cpu_nodestats for all online pgdats at boot
Paul Mackerras and Reza Arbab reported that machines with memoryless
nodes fail when vmstats are refreshed. Paul reported an oops as follows
Unable to handle kernel paging request for data at address 0xff7a10000
Faulting instruction address: 0xc000000000270cd0
Oops: Kernel access of bad area, sig: 11 [#1]
SMP NR_CPUS=2048 NUMA PowerNV
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.7.0-kvm+ #118
task: c000000ff0680010 task.stack: c000000ff0704000
NIP: c000000000270cd0 LR: c000000000270ce8 CTR: 0000000000000000
REGS: c000000ff0707900 TRAP: 0300 Not tainted (4.7.0-kvm+)
MSR: 9000000102009033 <SF,HV,VEC,EE,ME,IR,DR,RI,LE,TM[E]> CR: 846b6824 XER: 20000000
CFAR: c000000000008768 DAR: 0000000ff7a10000 DSISR: 42000000 SOFTE: 1
NIP refresh_zone_stat_thresholds+0x80/0x240
LR refresh_zone_stat_thresholds+0x98/0x240
Call Trace:
refresh_zone_stat_thresholds+0xb8/0x240 (unreliable)
Both supplied potential fixes but one potentially misses checks and
another had redundant initialisations. This version initialises
per_cpu_nodestats on a per-pgdat basis instead of on a per-zone basis.
Link: http://lkml.kernel.org/r/20160804092404.GI2799@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reported-by: Paul Mackerras <paulus@ozlabs.org>
Reported-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Tested-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>