On Thu, Jul 22, 2021 at 12:37:46PM +0530, Aneesh Kumar K.V wrote:
> David Gibson <da...@gibson.dropbear.id.au> writes:
>
> > On Mon, Jun 28, 2021 at 08:41:15PM +0530, Aneesh Kumar K.V wrote:
> >> The associativity details of the newly added resourced are collected from
> >> the hypervisor via "ibm,configure-connector" rtas call. Update the numa
> >> distance details of the newly added numa node after the above call.
> >>
> >> Instead of updating NUMA distance every time we lookup a node id
> >> from the associativity property, add helpers that can be used
> >> during boot which does this only once. Also remove the distance
> >> update from node id lookup helpers.
> >>
> >> Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.ibm.com>
> >> ---
> >> arch/powerpc/mm/numa.c | 173 +++++++++++++-----
> >> arch/powerpc/platforms/pseries/hotplug-cpu.c | 2 +
> >> .../platforms/pseries/hotplug-memory.c | 2 +
> >> arch/powerpc/platforms/pseries/pseries.h | 1 +
> >> 4 files changed, 132 insertions(+), 46 deletions(-)
> >>
> >> diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
> >> index 0ec16999beef..7b142f79d600 100644
> >> --- a/arch/powerpc/mm/numa.c
> >> +++ b/arch/powerpc/mm/numa.c
> >> @@ -208,22 +208,6 @@ int __node_distance(int a, int b)
> >> }
> >> EXPORT_SYMBOL(__node_distance);
> >>
> >> -static void initialize_distance_lookup_table(int nid,
> >> - const __be32 *associativity)
> >> -{
> >> - int i;
> >> -
> >> - if (affinity_form != FORM1_AFFINITY)
> >> - return;
> >> -
> >> - for (i = 0; i < max_associativity_domain_index; i++) {
> >> - const __be32 *entry;
> >> -
> >> - entry = &associativity[be32_to_cpu(distance_ref_points[i]) - 1];
> >> - distance_lookup_table[nid][i] = of_read_number(entry, 1);
> >> - }
> >> -}
> >> -
> >> /*
> >> * Returns nid in the range [0..nr_node_ids], or -1 if no useful NUMA
> >> * info is found.
> >> @@ -241,15 +225,6 @@ static int associativity_to_nid(const __be32
> >> *associativity)
> >> /* POWER4 LPAR uses 0xffff as invalid node */
> >> if (nid == 0xffff || nid >= nr_node_ids)
> >> nid = NUMA_NO_NODE;
> >> -
> >> - if (nid > 0 &&
> >> - of_read_number(associativity, 1) >=
> >> max_associativity_domain_index) {
> >> - /*
> >> - * Skip the length field and send start of associativity array
> >> - */
> >> - initialize_distance_lookup_table(nid, associativity + 1);
> >> - }
> >> -
> >> out:
> >> return nid;
> >> }
> >> @@ -287,6 +262,49 @@ int of_node_to_nid(struct device_node *device)
> >> }
> >> EXPORT_SYMBOL(of_node_to_nid);
> >>
> >> +static void __initialize_form1_numa_distance(const __be32 *associativity)
> >> +{
> >> + int i, nid;
> >> +
> >> + if (affinity_form != FORM1_AFFINITY)
> >
> > Since this shouldn't be called on a !form1 system, this could be a
> > WARN_ON().
>
> The way we call functions currently, instead of doing
>
> if (affinity_form == FORM1_AFFINITY)
> __initialize_form1_numa_distance()
>
> We avoid doing the if check in multiple places. For example
> parse_numa_properties will fetch the associativity array to find the
> details of online node and set it online. We use the same code path to
> initialize distance.
>
> if (__vphn_get_associativity(i, vphn_assoc) == 0) {
> nid = associativity_to_nid(vphn_assoc);
> __initialize_form1_numa_distance(vphn_assoc);
> } else {
>
> cpu = of_get_cpu_node(i, NULL);
> BUG_ON(!cpu);
>
> associativity = of_get_associativity(cpu);
> if (associativity) {
> nid = associativity_to_nid(associativity);
> __initialize_form1_numa_distance(associativity);
> }
>
> We avoid the the if (affinity_form == FORM1_AFFINITY) check there by
> moving the check inside __initialize_form1_numa_distance().
Oh.. ok. The only caller I spotted was already doing a test against
affinity_form.
> >> + return;
> >> +
> >> + if (of_read_number(associativity, 1) >= primary_domain_index) {
> >> + nid = of_read_number(&associativity[primary_domain_index], 1);
> >
> > This computes the nid from the assoc array independently of
> > associativity_to_nid, which doesn't seem like a good idea. Wouldn't
> > it be better to call assocaitivity_to_nid(), then make the next bit
> > conditional on nid !== NUMA_NO_NODE?
>
> @@ -302,9 +302,8 @@ static void __initialize_form1_numa_distance(const __be32
> *associativity)
> if (affinity_form != FORM1_AFFINITY)
> return;
>
> - if (of_read_number(associativity, 1) >= primary_domain_index) {
> - nid = of_read_number(&associativity[primary_domain_index], 1);
> -
> + nid = associativity_to_nid(associativity);
> + if (nid != NUMA_NO_NODE) {
> for (i = 0; i < distance_ref_points_depth; i++) {
> const __be32 *entry;
Right.
> >
> >> +
> >> + for (i = 0; i < max_associativity_domain_index; i++) {
> >> + const __be32 *entry;
> >> +
> >> + entry =
> >> &associativity[be32_to_cpu(distance_ref_points[i])];
> >> + distance_lookup_table[nid][i] = of_read_number(entry,
> >> 1);
> >> + }
> >> + }
> >> +}
> >> +
> >> +static void initialize_form1_numa_distance(struct device_node *node)
> >> +{
> >> + const __be32 *associativity;
> >> +
> >> + associativity = of_get_associativity(node);
> >> + if (!associativity)
> >> + return;
> >> +
> >> + __initialize_form1_numa_distance(associativity);
> >> +}
> >> +
> >> +/*
> >> + * Used to update distance information w.r.t newly added node.
> >> + */
> >> +void update_numa_distance(struct device_node *node)
> >> +{
> >> + if (affinity_form == FORM0_AFFINITY)
> >> + return;
> >> + else if (affinity_form == FORM1_AFFINITY) {
> >> + initialize_form1_numa_distance(node);
> >> + return;
> >> + }
> >> +}
> >> +
> >> static int __init find_primary_domain_index(void)
> >> {
> >> int index;
> >> @@ -433,6 +451,48 @@ static int of_get_assoc_arrays(struct assoc_arrays
> >> *aa)
> >> return 0;
> >> }
> >>
> >> +static int get_nid_and_numa_distance(struct drmem_lmb *lmb)
> >> +{
> >> + struct assoc_arrays aa = { .arrays = NULL };
> >> + int default_nid = NUMA_NO_NODE;
> >> + int nid = default_nid;
> >> + int rc, index;
> >> +
> >> + if ((primary_domain_index < 0) || !numa_enabled)
> >
> > Under what circumstances could you get primary_domain_index < 0?
>
> IIUC that is to handle failure to parse device tree.
> ea9f5b702fe0215188fba2eda117419e4ae90a67
Ok.
> >
> >> + return default_nid;
Returning NUMA_NO_NODE explicitly, rather than an alias to it might be
clearer here, but it's not a big detail.
> >> +
> >> + rc = of_get_assoc_arrays(&aa);
> >> + if (rc)
> >> + return default_nid;
> >> +
> >> + if (primary_domain_index <= aa.array_sz &&
> >> + !(lmb->flags & DRCONF_MEM_AI_INVALID) && lmb->aa_index <
> >> aa.n_arrays) {
> >> + index = lmb->aa_index * aa.array_sz + primary_domain_index - 1;
> >
> > Does anywhere verify that primary_domain_index <= aa.array_sz?
>
> That is the first part of the check?
Oh, sorry, missed that. I think I was expecting it to be an early
exit, rather than folded into the rest of this complex condition.
>
> >
> >> + nid = of_read_number(&aa.arrays[index], 1);
> >> +
> >> + if (nid == 0xffff || nid >= nr_node_ids)
> >> + nid = default_nid;
> >> + if (nid > 0 && affinity_form == FORM1_AFFINITY) {
> >> + int i;
> >> + const __be32 *associativity;
> >> +
> >> + index = lmb->aa_index * aa.array_sz;
> >> + associativity = &aa.arrays[index];
> >> + /*
> >> + * lookup array associativity entries have different
> >> format
> >> + * There is no length of the array as the first element.
> >
> > The difference it very small, and this is not a hot path. Couldn't
> > you reduce a chunk of code by prepending aa.array_sz, then re-using
> > __initialize_form1_numa_distance. Or even making
> > __initialize_form1_numa_distance() take the length as a parameter.
>
> The changes are small but confusing w.r.t how we look at the
> associativity-lookup-arrays. The way we interpret associativity array
> and associativity lookup array using primary_domain_index is different.
> Hence the '-1' in the node lookup here.
They're really not, though. It's exactly the same interpretation of
the associativity array itself - it's just that one of them has the
array prepended with a (redundant) length. So you can make
__initialize_form1_numa_distance() work on the "bare" associativity
array, with a given length. Here you call it with aa.array_sz as the
length, and in the other place you call it with prop[0] as the length.
>
> index = lmb->aa_index * aa.array_sz + primary_domain_index - 1;
> nid = of_read_number(&aa.arrays[index], 1);
>
>
> >
> >> + */
> >> + for (i = 0; i < max_associativity_domain_index; i++) {
> >> + const __be32 *entry;
> >> +
> >> + entry =
> >> &associativity[be32_to_cpu(distance_ref_points[i]) - 1];
> >
> > Does anywhere verify that distance_ref_points[i] <= aa.array_size for
> > every i?
>
> We do check for
>
> if (primary_domain_index <= aa.array_sz &&
Right, but that doesn't check the other distance_ref_points entries.
Not that there's any reason to have extra entries with Form2, but we
still don't want stray array accesses.
>
> >
> >> + distance_lookup_table[nid][i] =
> >> of_read_number(entry, 1);
> >> + }
> >> + }
> >> + }
> >> + return nid;
> >> +}
> >> +
> >> /*
> >> * This is like of_node_to_nid_single() for memory represented in the
> >> * ibm,dynamic-reconfiguration-memory node.
> >> @@ -458,21 +518,14 @@ int of_drconf_to_nid_single(struct drmem_lmb *lmb)
> >>
> >> if (nid == 0xffff || nid >= nr_node_ids)
> >> nid = default_nid;
> >> -
> >> - if (nid > 0) {
> >> - index = lmb->aa_index * aa.array_sz;
> >> - initialize_distance_lookup_table(nid,
> >> - &aa.arrays[index]);
> >> - }
> >> }
> >> -
> >> return nid;
> >> }
> >>
> >> #ifdef CONFIG_PPC_SPLPAR
> >> -static int vphn_get_nid(long lcpu)
> >> +
> >> +static int __vphn_get_associativity(long lcpu, __be32 *associativity)
> >> {
> >> - __be32 associativity[VPHN_ASSOC_BUFSIZE] = {0};
> >> long rc, hwid;
> >>
> >> /*
> >> @@ -492,10 +545,22 @@ static int vphn_get_nid(long lcpu)
> >>
> >> rc = hcall_vphn(hwid, VPHN_FLAG_VCPU, associativity);
> >> if (rc == H_SUCCESS)
> >> - return associativity_to_nid(associativity);
> >> + return 0;
> >> }
> >>
> >> + return -1;
> >> +}
> >> +
> >> +static int vphn_get_nid(long lcpu)
> >> +{
> >> + __be32 associativity[VPHN_ASSOC_BUFSIZE] = {0};
> >> +
> >> +
> >> + if (!__vphn_get_associativity(lcpu, associativity))
> >> + return associativity_to_nid(associativity);
> >> +
> >> return NUMA_NO_NODE;
> >> +
> >> }
> >> #else
> >> static int vphn_get_nid(long unused)
> >> @@ -692,7 +757,7 @@ static int __init numa_setup_drmem_lmb(struct
> >> drmem_lmb *lmb,
> >> size = read_n_cells(n_mem_size_cells, usm);
> >> }
> >>
> >> - nid = of_drconf_to_nid_single(lmb);
> >> + nid = get_nid_and_numa_distance(lmb);
> >> fake_numa_create_new_node(((base + size) >> PAGE_SHIFT),
> >> &nid);
> >> node_set_online(nid);
> >> @@ -709,6 +774,7 @@ static int __init parse_numa_properties(void)
> >> struct device_node *memory;
> >> int default_nid = 0;
> >> unsigned long i;
> >> + const __be32 *associativity;
> >>
> >> if (numa_enabled == 0) {
> >> printk(KERN_WARNING "NUMA disabled by user\n");
> >> @@ -734,18 +800,30 @@ static int __init parse_numa_properties(void)
> >> * each node to be onlined must have NODE_DATA etc backing it.
> >> */
> >> for_each_present_cpu(i) {
> >> + __be32 vphn_assoc[VPHN_ASSOC_BUFSIZE];
> >> struct device_node *cpu;
> >> - int nid = vphn_get_nid(i);
> >> + int nid = NUMA_NO_NODE;
> >>
> >> - /*
> >> - * Don't fall back to default_nid yet -- we will plug
> >> - * cpus into nodes once the memory scan has discovered
> >> - * the topology.
> >> - */
> >> - if (nid == NUMA_NO_NODE) {
> >> + memset(vphn_assoc, 0, VPHN_ASSOC_BUFSIZE * sizeof(__be32));
> >
> > What's the memset() for? AFAICT you only look at vphn_assoc in the
> > branch where __vphn_get_associativity() succeeds.
>
> That was done to match the existing code. We do use a zero filled array
> when making that hcall in this code path. I don't see us doing that
> everywhere. But didn't want to change that behaviour in this patch.
>
> -static int vphn_get_nid(long lcpu)
> +
> +static int __vphn_get_associativity(long lcpu, __be32 *associativity)
> {
> - __be32 associativity[VPHN_ASSOC_BUFSIZE] = {0};
> long rc, hwid;
Ok, that makes sense.
>
> >
> >> +
> >> + if (__vphn_get_associativity(i, vphn_assoc) == 0) {
> >> + nid = associativity_to_nid(vphn_assoc);
> >> + __initialize_form1_numa_distance(vphn_assoc);
> >> + } else {
> >> +
> >> + /*
> >> + * Don't fall back to default_nid yet -- we will plug
> >> + * cpus into nodes once the memory scan has discovered
> >> + * the topology.
> >> + */
> >> cpu = of_get_cpu_node(i, NULL);
> >> BUG_ON(!cpu);
> >> - nid = of_node_to_nid_single(cpu);
> >> +
> >> + associativity = of_get_associativity(cpu);
> >> + if (associativity) {
> >> + nid = associativity_to_nid(associativity);
> >> + __initialize_form1_numa_distance(associativity);
> >> + }
> >> of_node_put(cpu);
> >> }
> >>
> >> @@ -781,8 +859,11 @@ static int __init parse_numa_properties(void)
> >> * have associativity properties. If none, then
> >> * everything goes to default_nid.
> >> */
> >> - nid = of_node_to_nid_single(memory);
> >> - if (nid < 0)
> >> + associativity = of_get_associativity(memory);
> >> + if (associativity) {
> >> + nid = associativity_to_nid(associativity);
> >> + __initialize_form1_numa_distance(associativity);
> >> + } else
> >> nid = default_nid;
> >>
> >> fake_numa_create_new_node(((start + size) >> PAGE_SHIFT), &nid);
> >> diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c
> >> b/arch/powerpc/platforms/pseries/hotplug-cpu.c
> >> index 7e970f81d8ff..778b6ab35f0d 100644
> >> --- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
> >> +++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
> >> @@ -498,6 +498,8 @@ static ssize_t dlpar_cpu_add(u32 drc_index)
> >> return saved_rc;
> >> }
> >>
> >> + update_numa_distance(dn);
> >> +
> >> rc = dlpar_online_cpu(dn);
> >> if (rc) {
> >> saved_rc = rc;
> >> diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c
> >> b/arch/powerpc/platforms/pseries/hotplug-memory.c
> >> index 36f66556a7c6..40d350f31a34 100644
> >> --- a/arch/powerpc/platforms/pseries/hotplug-memory.c
> >> +++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
> >> @@ -180,6 +180,8 @@ static int update_lmb_associativity_index(struct
> >> drmem_lmb *lmb)
> >> return -ENODEV;
> >> }
> >>
> >> + update_numa_distance(lmb_node);
> >> +
> >> dr_node = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
> >> if (!dr_node) {
> >> dlpar_free_cc_nodes(lmb_node);
> >> diff --git a/arch/powerpc/platforms/pseries/pseries.h
> >> b/arch/powerpc/platforms/pseries/pseries.h
> >> index 1f051a786fb3..663a0859cf13 100644
> >> --- a/arch/powerpc/platforms/pseries/pseries.h
> >> +++ b/arch/powerpc/platforms/pseries/pseries.h
> >> @@ -113,4 +113,5 @@ extern u32 pseries_security_flavor;
> >> void pseries_setup_security_mitigations(void);
> >> void pseries_lpar_read_hblkrm_characteristics(void);
> >>
> >> +void update_numa_distance(struct device_node *node);
> >> #endif /* _PSERIES_PSERIES_H */
> >
>
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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