Messages in this thread | | | From | Tarun Sahu <> | Subject | Re: [PATCH v3] dax/kmem: Pass valid argument to memory_group_register_static | Date | Fri, 30 Jun 2023 09:11:43 +0530 |
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Hi,
This is just a gentle reminder, If any other information is needed.
Tarun Sahu <tsahu@linux.ibm.com> writes:
> memory_group_register_static takes maximum number of pages as the argument > while dev_dax_kmem_probe passes total_len (in bytes) as the argument. > > IIUC, I don't see any crash/panic impact as such. As, > memory_group_register_static just set the max_pages limit which is used in > auto_movable_zone_for_pfn to determine the zone. > > which might cause these condition to behave differently, > > This will be true always so jump will happen to kernel_zone > ... > if (!auto_movable_can_online_movable(NUMA_NO_NODE, group, nr_pages)) > goto kernel_zone; > > ... > kernel_zone: > return default_kernel_zone_for_pfn(nid, pfn, nr_pages); > > Here, In below, zone_intersects compare range will be larger as nr_pages > will be higher (derived from total_len passed in dev_dax_kmem_probe). > > ... > static struct zone *default_kernel_zone_for_pfn(int nid, unsigned long start_pfn, > unsigned long nr_pages) > { > struct pglist_data *pgdat = NODE_DATA(nid); > int zid; > > for (zid = 0; zid < ZONE_NORMAL; zid++) { > struct zone *zone = &pgdat->node_zones[zid]; > > if (zone_intersects(zone, start_pfn, nr_pages)) > return zone; > } > > return &pgdat->node_zones[ZONE_NORMAL]; > } > > Incorrect zone will be returned here, which in later time might cause bigger > problem. > > Fixes: eedf634aac3b ("dax/kmem: use a single static memory group for a single probed unit") > Signed-off-by: Tarun Sahu <tsahu@linux.ibm.com> > Reviewed-by: Vishal Verma <vishal.l.verma@intel.com> > --- > V3<-V2 > 1. Removed skip characters. > > V2<-V1 > 1. Added more details to commit message > > > drivers/dax/kmem.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c > index 7b36db6f1cbd..898ca9505754 100644 > --- a/drivers/dax/kmem.c > +++ b/drivers/dax/kmem.c > @@ -99,7 +99,7 @@ static int dev_dax_kmem_probe(struct dev_dax *dev_dax) > if (!data->res_name) > goto err_res_name; > > - rc = memory_group_register_static(numa_node, total_len); > + rc = memory_group_register_static(numa_node, PFN_UP(total_len)); > if (rc < 0) > goto err_reg_mgid; > data->mgid = rc; > -- > 2.31.1
~Tarun
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