[PATCH v4 06/13] mm/mempolicy: kill v.preferred_nodes

From: Feng Tang
Date: Tue Mar 16 2021 - 23:41:39 EST

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From: Ben Widawsky <ben.widawsky@xxxxxxxxx>

Now that preferred_nodes is just a mask, and policies are mutually
exclusive, there is no reason to have a separate mask.

This patch is optional. It definitely helps clean up code in future
patches, but there is no functional difference to leaving it with the
previous name. I do believe it helps demonstrate the exclusivity of the
fields.

Link: https://lore.kernel.org/r/20200630212517.308045-7-ben.widawsky@xxxxxxxxx
Signed-off-by: Ben Widawsky <ben.widawsky@xxxxxxxxx>
Signed-off-by: Feng Tang <feng.tang@xxxxxxxxx>
---
include/linux/mempolicy.h | 6 +--
mm/mempolicy.c | 114 ++++++++++++++++++++++------------------------
2 files changed, 56 insertions(+), 64 deletions(-)

diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h
index 23ee105..ec811c3 100644
--- a/include/linux/mempolicy.h
+++ b/include/linux/mempolicy.h
@@ -46,11 +46,7 @@ struct mempolicy {
atomic_t refcnt;
unsigned short mode; /* See MPOL_* above */
unsigned short flags; /* See set_mempolicy() MPOL_F_* above */
- union {
- nodemask_t preferred_nodes; /* preferred */
- nodemask_t nodes; /* interleave/bind */
- /* undefined for default */
- } v;
+ nodemask_t nodes; /* interleave/bind/many */
union {
nodemask_t cpuset_mems_allowed; /* relative to these nodes */
nodemask_t user_nodemask; /* nodemask passed by user */
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index fbfa3ce..eba207e 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -199,7 +199,7 @@ static int mpol_new_interleave(struct mempolicy *pol, const nodemask_t *nodes)
{
if (nodes_empty(*nodes))
return -EINVAL;
- pol->v.nodes = *nodes;
+ pol->nodes = *nodes;
return 0;
}

@@ -211,7 +211,7 @@ static int mpol_new_preferred_many(struct mempolicy *pol,
else if (nodes_empty(*nodes))
return -EINVAL; /* no allowed nodes */
else
- pol->v.preferred_nodes = *nodes;
+ pol->nodes = *nodes;
return 0;
}

@@ -235,7 +235,7 @@ static int mpol_new_bind(struct mempolicy *pol, const nodemask_t *nodes)
{
if (nodes_empty(*nodes))
return -EINVAL;
- pol->v.nodes = *nodes;
+ pol->nodes = *nodes;
return 0;
}

@@ -352,15 +352,15 @@ static void mpol_rebind_nodemask(struct mempolicy *pol, const nodemask_t *nodes)
else if (pol->flags & MPOL_F_RELATIVE_NODES)
mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
else {
- nodes_remap(tmp, pol->v.nodes,pol->w.cpuset_mems_allowed,
- *nodes);
+ nodes_remap(tmp, pol->nodes, pol->w.cpuset_mems_allowed,
+ *nodes);
pol->w.cpuset_mems_allowed = *nodes;
}

if (nodes_empty(tmp))
tmp = *nodes;

- pol->v.nodes = tmp;
+ pol->nodes = tmp;
}

static void mpol_rebind_preferred_common(struct mempolicy *pol,
@@ -373,17 +373,17 @@ static void mpol_rebind_preferred_common(struct mempolicy *pol,
int node = first_node(pol->w.user_nodemask);

if (node_isset(node, *nodes)) {
- pol->v.preferred_nodes = nodemask_of_node(node);
+ pol->nodes = nodemask_of_node(node);
pol->flags &= ~MPOL_F_LOCAL;
} else
pol->flags |= MPOL_F_LOCAL;
} else if (pol->flags & MPOL_F_RELATIVE_NODES) {
mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
- pol->v.preferred_nodes = tmp;
+ pol->nodes = tmp;
} else if (!(pol->flags & MPOL_F_LOCAL)) {
- nodes_remap(tmp, pol->v.preferred_nodes,
- pol->w.cpuset_mems_allowed, *preferred_nodes);
- pol->v.preferred_nodes = tmp;
+ nodes_remap(tmp, pol->nodes, pol->w.cpuset_mems_allowed,
+ *preferred_nodes);
+ pol->nodes = tmp;
pol->w.cpuset_mems_allowed = *nodes;
}
}
@@ -963,14 +963,14 @@ static void get_policy_nodemask(struct mempolicy *p, nodemask_t *nodes)
switch (p->mode) {
case MPOL_BIND:
case MPOL_INTERLEAVE:
- *nodes = p->v.nodes;
+ *nodes = p->nodes;
break;
case MPOL_PREFERRED_MANY:
- *nodes = p->v.preferred_nodes;
+ *nodes = p->nodes;
break;
case MPOL_PREFERRED:
if (!(p->flags & MPOL_F_LOCAL))
- *nodes = p->v.preferred_nodes;
+ *nodes = p->nodes;
/* else return empty node mask for local allocation */
break;
default:
@@ -1056,7 +1056,7 @@ static long do_get_mempolicy(int *policy, nodemask_t *nmask,
*policy = err;
} else if (pol == current->mempolicy &&
pol->mode == MPOL_INTERLEAVE) {
- *policy = next_node_in(current->il_prev, pol->v.nodes);
+ *policy = next_node_in(current->il_prev, pol->nodes);
} else {
err = -EINVAL;
goto out;
@@ -1908,14 +1908,14 @@ static int apply_policy_zone(struct mempolicy *policy, enum zone_type zone)
BUG_ON(dynamic_policy_zone == ZONE_MOVABLE);

/*
- * if policy->v.nodes has movable memory only,
+ * if policy->nodes has movable memory only,
* we apply policy when gfp_zone(gfp) = ZONE_MOVABLE only.
*
- * policy->v.nodes is intersect with node_states[N_MEMORY].
+ * policy->nodes is intersect with node_states[N_MEMORY].
* so if the following test faile, it implies
- * policy->v.nodes has movable memory only.
+ * policy->nodes has movable memory only.
*/
- if (!nodes_intersects(policy->v.nodes, node_states[N_HIGH_MEMORY]))
+ if (!nodes_intersects(policy->nodes, node_states[N_HIGH_MEMORY]))
dynamic_policy_zone = ZONE_MOVABLE;

return zone >= dynamic_policy_zone;
@@ -1929,9 +1929,9 @@ nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy)
{
/* Lower zones don't get a nodemask applied for MPOL_BIND */
if (unlikely(policy->mode == MPOL_BIND) &&
- apply_policy_zone(policy, gfp_zone(gfp)) &&
- cpuset_nodemask_valid_mems_allowed(&policy->v.nodes))
- return &policy->v.nodes;
+ apply_policy_zone(policy, gfp_zone(gfp)) &&
+ cpuset_nodemask_valid_mems_allowed(&policy->nodes))
+ return &policy->nodes;

return NULL;
}
@@ -1942,7 +1942,7 @@ static int policy_node(gfp_t gfp, struct mempolicy *policy, int nd)
if ((policy->mode == MPOL_PREFERRED ||
policy->mode == MPOL_PREFERRED_MANY) &&
!(policy->flags & MPOL_F_LOCAL)) {
- nd = first_node(policy->v.preferred_nodes);
+ nd = first_node(policy->nodes);
} else {
/*
* __GFP_THISNODE shouldn't even be used with the bind policy
@@ -1961,7 +1961,7 @@ static unsigned interleave_nodes(struct mempolicy *policy)
unsigned next;
struct task_struct *me = current;

- next = next_node_in(me->il_prev, policy->v.nodes);
+ next = next_node_in(me->il_prev, policy->nodes);
if (next < MAX_NUMNODES)
me->il_prev = next;
return next;
@@ -1989,7 +1989,7 @@ unsigned int mempolicy_slab_node(void)
/*
* handled MPOL_F_LOCAL above
*/
- return first_node(policy->v.preferred_nodes);
+ return first_node(policy->nodes);

case MPOL_INTERLEAVE:
return interleave_nodes(policy);
@@ -2005,7 +2005,7 @@ unsigned int mempolicy_slab_node(void)
enum zone_type highest_zoneidx = gfp_zone(GFP_KERNEL);
zonelist = &NODE_DATA(node)->node_zonelists[ZONELIST_FALLBACK];
z = first_zones_zonelist(zonelist, highest_zoneidx,
- &policy->v.nodes);
+ &policy->nodes);
return z->zone ? zone_to_nid(z->zone) : node;
}

@@ -2016,12 +2016,12 @@ unsigned int mempolicy_slab_node(void)

/*
* Do static interleaving for a VMA with known offset @n. Returns the n'th
- * node in pol->v.nodes (starting from n=0), wrapping around if n exceeds the
+ * node in pol->nodes (starting from n=0), wrapping around if n exceeds the
* number of present nodes.
*/
static unsigned offset_il_node(struct mempolicy *pol, unsigned long n)
{
- unsigned nnodes = nodes_weight(pol->v.nodes);
+ unsigned nnodes = nodes_weight(pol->nodes);
unsigned target;
int i;
int nid;
@@ -2029,9 +2029,9 @@ static unsigned offset_il_node(struct mempolicy *pol, unsigned long n)
if (!nnodes)
return numa_node_id();
target = (unsigned int)n % nnodes;
- nid = first_node(pol->v.nodes);
+ nid = first_node(pol->nodes);
for (i = 0; i < target; i++)
- nid = next_node(nid, pol->v.nodes);
+ nid = next_node(nid, pol->nodes);
return nid;
}

@@ -2087,7 +2087,7 @@ int huge_node(struct vm_area_struct *vma, unsigned long addr, gfp_t gfp_flags,
} else {
nid = policy_node(gfp_flags, *mpol, numa_node_id());
if ((*mpol)->mode == MPOL_BIND)
- *nodemask = &(*mpol)->v.nodes;
+ *nodemask = &(*mpol)->nodes;
}
return nid;
}
@@ -2120,19 +2120,19 @@ bool init_nodemask_of_mempolicy(nodemask_t *mask)
mempolicy = current->mempolicy;
switch (mempolicy->mode) {
case MPOL_PREFERRED_MANY:
- *mask = mempolicy->v.preferred_nodes;
+ *mask = mempolicy->nodes;
break;
case MPOL_PREFERRED:
if (mempolicy->flags & MPOL_F_LOCAL)
nid = numa_node_id();
else
- nid = first_node(mempolicy->v.preferred_nodes);
+ nid = first_node(mempolicy->nodes);
init_nodemask_of_node(mask, nid);
break;

case MPOL_BIND:
case MPOL_INTERLEAVE:
- *mask = mempolicy->v.nodes;
+ *mask = mempolicy->nodes;
break;

default:
@@ -2177,11 +2177,11 @@ bool mempolicy_nodemask_intersects(struct task_struct *tsk,
*/
break;
case MPOL_PREFERRED_MANY:
- ret = nodes_intersects(mempolicy->v.preferred_nodes, *mask);
+ ret = nodes_intersects(mempolicy->nodes, *mask);
break;
case MPOL_BIND:
case MPOL_INTERLEAVE:
- ret = nodes_intersects(mempolicy->v.nodes, *mask);
+ ret = nodes_intersects(mempolicy->nodes, *mask);
break;
default:
BUG();
@@ -2270,7 +2270,7 @@ alloc_pages_vma(gfp_t gfp, int order, struct vm_area_struct *vma,
if ((pol->mode == MPOL_PREFERRED ||
pol->mode == MPOL_PREFERRED_MANY) &&
!(pol->flags & MPOL_F_LOCAL))
- hpage_node = first_node(pol->v.preferred_nodes);
+ hpage_node = first_node(pol->nodes);

nmask = policy_nodemask(gfp, pol);
if (!nmask || node_isset(hpage_node, *nmask)) {
@@ -2404,15 +2404,14 @@ bool __mpol_equal(struct mempolicy *a, struct mempolicy *b)
switch (a->mode) {
case MPOL_BIND:
case MPOL_INTERLEAVE:
- return !!nodes_equal(a->v.nodes, b->v.nodes);
+ return !!nodes_equal(a->nodes, b->nodes);
case MPOL_PREFERRED_MANY:
- return !!nodes_equal(a->v.preferred_nodes,
- b->v.preferred_nodes);
+ return !!nodes_equal(a->nodes, b->nodes);
case MPOL_PREFERRED:
/* a's ->flags is the same as b's */
if (a->flags & MPOL_F_LOCAL)
return true;
- return nodes_equal(a->v.preferred_nodes, b->v.preferred_nodes);
+ return nodes_equal(a->nodes, b->nodes);
default:
BUG();
return false;
@@ -2556,13 +2555,13 @@ int mpol_misplaced(struct page *page, struct vm_area_struct *vma, unsigned long
if (pol->flags & MPOL_F_LOCAL)
polnid = numa_node_id();
else
- polnid = first_node(pol->v.preferred_nodes);
+ polnid = first_node(pol->nodes);
break;

case MPOL_BIND:
/* Optimize placement among multiple nodes via NUMA balancing */
if (pol->flags & MPOL_F_MORON) {
- if (node_isset(thisnid, pol->v.nodes))
+ if (node_isset(thisnid, pol->nodes))
break;
goto out;
}
@@ -2573,12 +2572,11 @@ int mpol_misplaced(struct page *page, struct vm_area_struct *vma, unsigned long
* else select nearest allowed node, if any.
* If no allowed nodes, use current [!misplaced].
*/
- if (node_isset(curnid, pol->v.nodes))
+ if (node_isset(curnid, pol->nodes))
goto out;
- z = first_zones_zonelist(
- node_zonelist(numa_node_id(), GFP_HIGHUSER),
- gfp_zone(GFP_HIGHUSER),
- &pol->v.nodes);
+ z = first_zones_zonelist(node_zonelist(numa_node_id(),
+ GFP_HIGHUSER),
+ gfp_zone(GFP_HIGHUSER), &pol->nodes);
polnid = zone_to_nid(z->zone);
break;

@@ -2779,11 +2777,9 @@ int mpol_set_shared_policy(struct shared_policy *info,
struct sp_node *new = NULL;
unsigned long sz = vma_pages(vma);

- pr_debug("set_shared_policy %lx sz %lu %d %d %lx\n",
- vma->vm_pgoff,
- sz, npol ? npol->mode : -1,
- npol ? npol->flags : -1,
- npol ? nodes_addr(npol->v.nodes)[0] : NUMA_NO_NODE);
+ pr_debug("set_shared_policy %lx sz %lu %d %d %lx\n", vma->vm_pgoff, sz,
+ npol ? npol->mode : -1, npol ? npol->flags : -1,
+ npol ? nodes_addr(npol->nodes)[0] : NUMA_NO_NODE);

if (npol) {
new = sp_alloc(vma->vm_pgoff, vma->vm_pgoff + sz, npol);
@@ -2877,11 +2873,11 @@ void __init numa_policy_init(void)
0, SLAB_PANIC, NULL);

for_each_node(nid) {
- preferred_node_policy[nid] = (struct mempolicy) {
+ preferred_node_policy[nid] = (struct mempolicy){
.refcnt = ATOMIC_INIT(1),
.mode = MPOL_PREFERRED,
.flags = MPOL_F_MOF | MPOL_F_MORON,
- .v = { .preferred_nodes = nodemask_of_node(nid), },
+ .nodes = nodemask_of_node(nid),
};
}

@@ -3047,9 +3043,9 @@ int mpol_parse_str(char *str, struct mempolicy **mpol)
* for /proc/mounts, /proc/pid/mounts and /proc/pid/mountinfo.
*/
if (mode != MPOL_PREFERRED)
- new->v.nodes = nodes;
+ new->nodes = nodes;
else if (nodelist)
- new->v.preferred_nodes = nodemask_of_node(first_node(nodes));
+ new->nodes = nodemask_of_node(first_node(nodes));
else
new->flags |= MPOL_F_LOCAL;

@@ -3105,11 +3101,11 @@ void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol)
if (flags & MPOL_F_LOCAL)
mode = MPOL_LOCAL;
else
- nodes_or(nodes, nodes, pol->v.preferred_nodes);
+ nodes_or(nodes, nodes, pol->nodes);
break;
case MPOL_BIND:
case MPOL_INTERLEAVE:
- nodes = pol->v.nodes;
+ nodes = pol->nodes;
break;
default:
WARN_ON_ONCE(1);
--
2.7.4

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