| Message ID | 20220304093409.25829-15-linmiaohe@huawei.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | A few cleanup and fixup patches for migration | expand |
On 3/4/2022 5:34 PM, Miaohe Lin wrote: > If we failed to setup hotplug state callbacks for mm/demotion:online in > some corner cases, node_demotion will be left uninitialized. Invalid node > might be returned from the next_demotion_node() when doing reclaim-based > migration. Use kcalloc to allocate node_demotion to fix the issue. > > Fixes: ac16ec835314 ("mm: migrate: support multiple target nodes demotion") > Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> > --- > mm/migrate.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/mm/migrate.c b/mm/migrate.c > index 279940c0c064..7b1c0b988234 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -2516,9 +2516,9 @@ static int __init migrate_on_reclaim_init(void) > { > int ret; > > - node_demotion = kmalloc_array(nr_node_ids, > - sizeof(struct demotion_nodes), > - GFP_KERNEL); > + node_demotion = kcalloc(nr_node_ids, > + sizeof(struct demotion_nodes), > + GFP_KERNEL); Nit: not sure if this is worthy of this rare corner case, but I think the target demotion nodes' default value should be NUMA_NO_NODE instead of 0.
Baolin Wang <baolin.wang@linux.alibaba.com> writes: > On 3/4/2022 5:34 PM, Miaohe Lin wrote: >> If we failed to setup hotplug state callbacks for mm/demotion:online in >> some corner cases, node_demotion will be left uninitialized. Invalid node >> might be returned from the next_demotion_node() when doing reclaim-based >> migration. Use kcalloc to allocate node_demotion to fix the issue. >> Fixes: ac16ec835314 ("mm: migrate: support multiple target nodes >> demotion") >> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> >> --- >> mm/migrate.c | 6 +++--- >> 1 file changed, 3 insertions(+), 3 deletions(-) >> diff --git a/mm/migrate.c b/mm/migrate.c >> index 279940c0c064..7b1c0b988234 100644 >> --- a/mm/migrate.c >> +++ b/mm/migrate.c >> @@ -2516,9 +2516,9 @@ static int __init migrate_on_reclaim_init(void) >> { >> int ret; >> - node_demotion = kmalloc_array(nr_node_ids, >> - sizeof(struct demotion_nodes), >> - GFP_KERNEL); >> + node_demotion = kcalloc(nr_node_ids, >> + sizeof(struct demotion_nodes), >> + GFP_KERNEL); > > Nit: not sure if this is worthy of this rare corner case, but I think > the target demotion nodes' default value should be NUMA_NO_NODE > instead of 0. The "nr" field of "struct demotion_nodes" should be initialized as 0. I think that is checked before "nodes[]" field. Best Regards, Huang, Ying
Miaohe Lin <linmiaohe@huawei.com> writes: > If we failed to setup hotplug state callbacks for mm/demotion:online in > some corner cases, node_demotion will be left uninitialized. Invalid node > might be returned from the next_demotion_node() when doing reclaim-based > migration. Use kcalloc to allocate node_demotion to fix the issue. > > Fixes: ac16ec835314 ("mm: migrate: support multiple target nodes demotion") > Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> LGTM! Thanks! Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Best Regards, Huang, Ying > --- > mm/migrate.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/mm/migrate.c b/mm/migrate.c > index 279940c0c064..7b1c0b988234 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -2516,9 +2516,9 @@ static int __init migrate_on_reclaim_init(void) > { > int ret; > > - node_demotion = kmalloc_array(nr_node_ids, > - sizeof(struct demotion_nodes), > - GFP_KERNEL); > + node_demotion = kcalloc(nr_node_ids, > + sizeof(struct demotion_nodes), > + GFP_KERNEL); > WARN_ON(!node_demotion); > > ret = cpuhp_setup_state_nocalls(CPUHP_MM_DEMOTION_DEAD, "mm/demotion:offline",
On 3/7/2022 1:14 PM, Huang, Ying wrote: > Baolin Wang <baolin.wang@linux.alibaba.com> writes: > >> On 3/4/2022 5:34 PM, Miaohe Lin wrote: >>> If we failed to setup hotplug state callbacks for mm/demotion:online in >>> some corner cases, node_demotion will be left uninitialized. Invalid node >>> might be returned from the next_demotion_node() when doing reclaim-based >>> migration. Use kcalloc to allocate node_demotion to fix the issue. >>> Fixes: ac16ec835314 ("mm: migrate: support multiple target nodes >>> demotion") >>> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> >>> --- >>> mm/migrate.c | 6 +++--- >>> 1 file changed, 3 insertions(+), 3 deletions(-) >>> diff --git a/mm/migrate.c b/mm/migrate.c >>> index 279940c0c064..7b1c0b988234 100644 >>> --- a/mm/migrate.c >>> +++ b/mm/migrate.c >>> @@ -2516,9 +2516,9 @@ static int __init migrate_on_reclaim_init(void) >>> { >>> int ret; >>> - node_demotion = kmalloc_array(nr_node_ids, >>> - sizeof(struct demotion_nodes), >>> - GFP_KERNEL); >>> + node_demotion = kcalloc(nr_node_ids, >>> + sizeof(struct demotion_nodes), >>> + GFP_KERNEL); >> >> Nit: not sure if this is worthy of this rare corner case, but I think >> the target demotion nodes' default value should be NUMA_NO_NODE >> instead of 0. > > The "nr" field of "struct demotion_nodes" should be initialized as 0. I > think that is checked before "nodes[]" field. Right, but it will be confusing that if nr = 0, while the nodes[] still contains valid node id 0. While we are at this, why not initialize the node_demotion structure with a clear default value? Anyway, no strong opinion on this :)
On 2022/3/7 15:04, Baolin Wang wrote: > > > On 3/7/2022 1:14 PM, Huang, Ying wrote: >> Baolin Wang <baolin.wang@linux.alibaba.com> writes: >> >>> On 3/4/2022 5:34 PM, Miaohe Lin wrote: >>>> If we failed to setup hotplug state callbacks for mm/demotion:online in >>>> some corner cases, node_demotion will be left uninitialized. Invalid node >>>> might be returned from the next_demotion_node() when doing reclaim-based >>>> migration. Use kcalloc to allocate node_demotion to fix the issue. >>>> Fixes: ac16ec835314 ("mm: migrate: support multiple target nodes >>>> demotion") >>>> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> >>>> --- >>>> mm/migrate.c | 6 +++--- >>>> 1 file changed, 3 insertions(+), 3 deletions(-) >>>> diff --git a/mm/migrate.c b/mm/migrate.c >>>> index 279940c0c064..7b1c0b988234 100644 >>>> --- a/mm/migrate.c >>>> +++ b/mm/migrate.c >>>> @@ -2516,9 +2516,9 @@ static int __init migrate_on_reclaim_init(void) >>>> { >>>> int ret; >>>> - node_demotion = kmalloc_array(nr_node_ids, >>>> - sizeof(struct demotion_nodes), >>>> - GFP_KERNEL); >>>> + node_demotion = kcalloc(nr_node_ids, >>>> + sizeof(struct demotion_nodes), >>>> + GFP_KERNEL); >>> >>> Nit: not sure if this is worthy of this rare corner case, but I think >>> the target demotion nodes' default value should be NUMA_NO_NODE >>> instead of 0. >> >> The "nr" field of "struct demotion_nodes" should be initialized as 0. I >> think that is checked before "nodes[]" field. > > Right, but it will be confusing that if nr = 0, while the nodes[] still contains valid node id 0. While we are at this, why not initialize the node_demotion structure with a clear default value? Anyway, no strong opinion on this :) IMO, this might not deserve initializing the node_demotion structure with a clear default value as cpuhp_setup_state fails at init time should be a rare case. Thanks both of you. > .
diff --git a/mm/migrate.c b/mm/migrate.c index 279940c0c064..7b1c0b988234 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -2516,9 +2516,9 @@ static int __init migrate_on_reclaim_init(void) { int ret; - node_demotion = kmalloc_array(nr_node_ids, - sizeof(struct demotion_nodes), - GFP_KERNEL); + node_demotion = kcalloc(nr_node_ids, + sizeof(struct demotion_nodes), + GFP_KERNEL); WARN_ON(!node_demotion); ret = cpuhp_setup_state_nocalls(CPUHP_MM_DEMOTION_DEAD, "mm/demotion:offline",
If we failed to setup hotplug state callbacks for mm/demotion:online in some corner cases, node_demotion will be left uninitialized. Invalid node might be returned from the next_demotion_node() when doing reclaim-based migration. Use kcalloc to allocate node_demotion to fix the issue. Fixes: ac16ec835314 ("mm: migrate: support multiple target nodes demotion") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> --- mm/migrate.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)