| Message ID | 20160804092404.GI2799@techsingularity.net (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
On Thu, Aug 04, 2016 at 10:24:04AM +0100, Mel Gorman wrote: >This has been compile-tested and boot-tested on a 32-bit KVM only. A >memoryless system was not available to test the patch with. A confirmation >from Paul and Reza that it resolves their problem is welcome. Works for me. Thanks, Mel! Tested-by: Reza Arbab <arbab@linux.vnet.ibm.com>
On Thu, Aug 04, 2016 at 10:24:04AM +0100, Mel Gorman wrote: > Paul Mackerras and Reza Arbab reported that machines with memoryless nodes > fails when vmstats are refreshed. Paul reported an oops as follows > > [ 1.713998] Unable to handle kernel paging request for data at address 0xff7a10000 > [ 1.714164] Faulting instruction address: 0xc000000000270cd0 > [ 1.714304] Oops: Kernel access of bad area, sig: 11 [#1] > [ 1.714414] SMP NR_CPUS=2048 NUMA PowerNV > [ 1.714530] Modules linked in: > [ 1.714647] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.7.0-kvm+ #118 > [ 1.714786] task: c000000ff0680010 task.stack: c000000ff0704000 > [ 1.714926] NIP: c000000000270cd0 LR: c000000000270ce8 CTR: 0000000000000000 > [ 1.715093] REGS: c000000ff0707900 TRAP: 0300 Not tainted (4.7.0-kvm+) > [ 1.715232] MSR: 9000000102009033 <SF,HV,VEC,EE,ME,IR,DR,RI,LE,TM[E]> CR: 846b6824 XER: 20000000 > [ 1.715748] CFAR: c000000000008768 DAR: 0000000ff7a10000 DSISR: 42000000 SOFTE: 1 > GPR00: c000000000270d08 c000000ff0707b80 c0000000011fb200 0000000000000000 > GPR04: 0000000000000800 0000000000000000 0000000000000000 0000000000000000 > GPR08: ffffffffffffffff 0000000000000000 0000000ff7a10000 c00000000122aae0 > GPR12: c000000000a1e440 c00000000fb80000 c00000000000c188 0000000000000000 > GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 > GPR20: 0000000000000000 0000000000000000 0000000000000000 c000000000cecad0 > GPR24: c000000000d035b8 c000000000d6cd18 c000000000d6cd18 c000001fffa86300 > GPR28: 0000000000000000 c000001fffa96300 c000000001230034 c00000000122eb18 > [ 1.717484] NIP [c000000000270cd0] refresh_zone_stat_thresholds+0x80/0x240 > [ 1.717568] LR [c000000000270ce8] refresh_zone_stat_thresholds+0x98/0x240 > [ 1.717648] Call Trace: > [ 1.717687] [c000000ff0707b80] [c000000000270d08] 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. > > Reported-by: Paul Mackerras <paulus@ozlabs.org> > Reported-by: Reza Arbab <arbab@linux.vnet.ibm.com> > Signed-off-by: Mel Gorman <mgorman@techsingularity.net> That works, thanks. Tested-by: Paul Mackerras <paulus@ozlabs.org>
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 39a372a2a1d6..fb975cec3518 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5257,11 +5257,6 @@ static void __meminit setup_zone_pageset(struct zone *zone) zone->pageset = alloc_percpu(struct per_cpu_pageset); for_each_possible_cpu(cpu) zone_pageset_init(zone, cpu); - - if (!zone->zone_pgdat->per_cpu_nodestats) { - zone->zone_pgdat->per_cpu_nodestats = - alloc_percpu(struct per_cpu_nodestat); - } } /* @@ -5270,10 +5265,15 @@ static void __meminit setup_zone_pageset(struct zone *zone) */ void __init setup_per_cpu_pageset(void) { + struct pglist_data *pgdat; struct zone *zone; for_each_populated_zone(zone) setup_zone_pageset(zone); + + for_each_online_pgdat(pgdat) + pgdat->per_cpu_nodestats = + alloc_percpu(struct per_cpu_nodestat); } static noinline __ref
Paul Mackerras and Reza Arbab reported that machines with memoryless nodes fails when vmstats are refreshed. Paul reported an oops as follows [ 1.713998] Unable to handle kernel paging request for data at address 0xff7a10000 [ 1.714164] Faulting instruction address: 0xc000000000270cd0 [ 1.714304] Oops: Kernel access of bad area, sig: 11 [#1] [ 1.714414] SMP NR_CPUS=2048 NUMA PowerNV [ 1.714530] Modules linked in: [ 1.714647] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.7.0-kvm+ #118 [ 1.714786] task: c000000ff0680010 task.stack: c000000ff0704000 [ 1.714926] NIP: c000000000270cd0 LR: c000000000270ce8 CTR: 0000000000000000 [ 1.715093] REGS: c000000ff0707900 TRAP: 0300 Not tainted (4.7.0-kvm+) [ 1.715232] MSR: 9000000102009033 <SF,HV,VEC,EE,ME,IR,DR,RI,LE,TM[E]> CR: 846b6824 XER: 20000000 [ 1.715748] CFAR: c000000000008768 DAR: 0000000ff7a10000 DSISR: 42000000 SOFTE: 1 GPR00: c000000000270d08 c000000ff0707b80 c0000000011fb200 0000000000000000 GPR04: 0000000000000800 0000000000000000 0000000000000000 0000000000000000 GPR08: ffffffffffffffff 0000000000000000 0000000ff7a10000 c00000000122aae0 GPR12: c000000000a1e440 c00000000fb80000 c00000000000c188 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR20: 0000000000000000 0000000000000000 0000000000000000 c000000000cecad0 GPR24: c000000000d035b8 c000000000d6cd18 c000000000d6cd18 c000001fffa86300 GPR28: 0000000000000000 c000001fffa96300 c000000001230034 c00000000122eb18 [ 1.717484] NIP [c000000000270cd0] refresh_zone_stat_thresholds+0x80/0x240 [ 1.717568] LR [c000000000270ce8] refresh_zone_stat_thresholds+0x98/0x240 [ 1.717648] Call Trace: [ 1.717687] [c000000ff0707b80] [c000000000270d08] 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. Reported-by: Paul Mackerras <paulus@ozlabs.org> Reported-by: Reza Arbab <arbab@linux.vnet.ibm.com> Signed-off-by: Mel Gorman <mgorman@techsingularity.net> --- This has been compile-tested and boot-tested on a 32-bit KVM only. A memoryless system was not available to test the patch with. A confirmation from Paul and Reza that it resolves their problem is welcome. mm/page_alloc.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)