Commit c36f6e6d authored by Hugh Dickins's avatar Hugh Dickins Committed by Andrew Morton
Browse files

mempolicy trivia: slightly more consistent naming 

Before getting down to work, do a little cleanup, mainly of inconsistent
variable naming.  I gave up trying to rationalize mpol versus pol versus
policy, and node versus nid, but let's avoid p and nd.  Remove a few
superfluous blank lines, but add one; and here prefer vma->vm_policy to
vma_policy(vma) - the latter being appropriate in other sources, which
have to allow for !CONFIG_NUMA.  That intriguing line about KERNEL_DS? 
should have gone in v2.6.15, when numa_policy_init() stopped using
set_mempolicy(2)'s system call handler.

Link: https://lkml.kernel.org/r/68287974-b6ae-7df-4ba-d19ddd69cbf@google.com


Signed-off-by: default avatarHugh Dickins <hughd@google.com>
Reviewed-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tejun heo <tj@kernel.org>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 7f1ee4e2

include/linux/mempolicy.h

+5 −6
Original line number Diff line number Diff line
@@ -124,10 +124,9 @@ struct shared_policy { 


int vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst);

void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol);

int mpol_set_shared_policy(struct shared_policy *info,

				struct vm_area_struct *vma,

				struct mempolicy *new);

void mpol_free_shared_policy(struct shared_policy *p);

int mpol_set_shared_policy(struct shared_policy *sp,

			   struct vm_area_struct *vma, struct mempolicy *mpol);

void mpol_free_shared_policy(struct shared_policy *sp);

struct mempolicy *mpol_shared_policy_lookup(struct shared_policy *sp,

					    unsigned long idx);
@@ -191,7 +190,7 @@ static inline bool mpol_equal(struct mempolicy *a, struct mempolicy *b) 
	return true;

}



static inline void mpol_put(struct mempolicy *p)

static inline void mpol_put(struct mempolicy *pol)

{

}
@@ -210,7 +209,7 @@ static inline void mpol_shared_policy_init(struct shared_policy *sp, 
{

}



static inline void mpol_free_shared_policy(struct shared_policy *p)

static inline void mpol_free_shared_policy(struct shared_policy *sp)

{

}

mm/mempolicy.c

+33 −40
Original line number Diff line number Diff line
@@ -52,7 +52,7 @@ 
 * on systems with highmem kernel lowmem allocation don't get policied.

 * Same with GFP_DMA allocations.

 *

 * For shmfs/tmpfs/hugetlbfs shared memory the policy is shared between

 * For shmem/tmpfs shared memory the policy is shared between

 * all users and remembered even when nobody has memory mapped.

 */
@@ -291,6 +291,7 @@ static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags, 
			return ERR_PTR(-EINVAL);

	} else if (nodes_empty(*nodes))

		return ERR_PTR(-EINVAL);



	policy = kmem_cache_alloc(policy_cache, GFP_KERNEL);

	if (!policy)

		return ERR_PTR(-ENOMEM);
@@ -303,11 +304,11 @@ static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags, 
}



/* Slow path of a mpol destructor. */

void __mpol_put(struct mempolicy *p)

void __mpol_put(struct mempolicy *pol)

{

	if (!atomic_dec_and_test(&p->refcnt))

	if (!atomic_dec_and_test(&pol->refcnt))

		return;

	kmem_cache_free(policy_cache, p);

	kmem_cache_free(policy_cache, pol);

}



static void mpol_rebind_default(struct mempolicy *pol, const nodemask_t *nodes)
@@ -364,7 +365,6 @@ static void mpol_rebind_policy(struct mempolicy *pol, const nodemask_t *newmask) 
 *

 * Called with task's alloc_lock held.

 */



void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new)

{

	mpol_rebind_policy(tsk->mempolicy, new);
@@ -375,7 +375,6 @@ void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new) 
 *

 * Call holding a reference to mm.  Takes mm->mmap_lock during call.

 */



void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new)

{

	struct vm_area_struct *vma;
@@ -800,7 +799,7 @@ static int mbind_range(struct vma_iterator *vmi, struct vm_area_struct *vma, 
		vmstart = vma->vm_start;

	}



	if (mpol_equal(vma_policy(vma), new_pol)) {

	if (mpol_equal(vma->vm_policy, new_pol)) {

		*prev = vma;

		return 0;

	}
@@ -855,18 +854,18 @@ static long do_set_mempolicy(unsigned short mode, unsigned short flags, 
 *

 * Called with task's alloc_lock held

 */

static void get_policy_nodemask(struct mempolicy *p, nodemask_t *nodes)

static void get_policy_nodemask(struct mempolicy *pol, nodemask_t *nodes)

{

	nodes_clear(*nodes);

	if (p == &default_policy)

	if (pol == &default_policy)

		return;



	switch (p->mode) {

	switch (pol->mode) {

	case MPOL_BIND:

	case MPOL_INTERLEAVE:

	case MPOL_PREFERRED:

	case MPOL_PREFERRED_MANY:

		*nodes = p->nodes;

		*nodes = pol->nodes;

		break;

	case MPOL_LOCAL:

		/* return empty node mask for local allocation */
@@ -1634,7 +1633,6 @@ static int kernel_migrate_pages(pid_t pid, unsigned long maxnode, 
out_put:

	put_task_struct(task);

	goto out;



}



SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode,
@@ -1644,7 +1642,6 @@ SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode, 
	return kernel_migrate_pages(pid, maxnode, old_nodes, new_nodes);

}





/* Retrieve NUMA policy */

static int kernel_get_mempolicy(int __user *policy,

				unsigned long __user *nmask,
@@ -1827,10 +1824,10 @@ nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy) 
 * policy_node() is always coupled with policy_nodemask(), which

 * secures the nodemask limit for 'bind' and 'prefer-many' policy.

 */

static int policy_node(gfp_t gfp, struct mempolicy *policy, int nd)

static int policy_node(gfp_t gfp, struct mempolicy *policy, int nid)

{

	if (policy->mode == MPOL_PREFERRED) {

		nd = first_node(policy->nodes);

		nid = first_node(policy->nodes);

	} else {

		/*

		 * __GFP_THISNODE shouldn't even be used with the bind policy
@@ -1845,19 +1842,18 @@ static int policy_node(gfp_t gfp, struct mempolicy *policy, int nd) 
	    policy->home_node != NUMA_NO_NODE)

		return policy->home_node;



	return nd;

	return nid;

}



/* Do dynamic interleaving for a process */

static unsigned interleave_nodes(struct mempolicy *policy)

static unsigned int interleave_nodes(struct mempolicy *policy)

{

	unsigned next;

	struct task_struct *me = current;

	unsigned int nid;



	next = next_node_in(me->il_prev, policy->nodes);

	if (next < MAX_NUMNODES)

		me->il_prev = next;

	return next;

	nid = next_node_in(current->il_prev, policy->nodes);

	if (nid < MAX_NUMNODES)

		current->il_prev = nid;

	return nid;

}



/*
@@ -2347,7 +2343,7 @@ unsigned long alloc_pages_bulk_array_mempolicy(gfp_t gfp, 


int vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst)

{

	struct mempolicy *pol = mpol_dup(vma_policy(src));

	struct mempolicy *pol = mpol_dup(src->vm_policy);



	if (IS_ERR(pol))

		return PTR_ERR(pol);
@@ -2771,40 +2767,40 @@ void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol) 
	}

}



int mpol_set_shared_policy(struct shared_policy *info,

			struct vm_area_struct *vma, struct mempolicy *npol)

int mpol_set_shared_policy(struct shared_policy *sp,

			struct vm_area_struct *vma, struct mempolicy *pol)

{

	int err;

	struct sp_node *new = NULL;

	unsigned long sz = vma_pages(vma);



	if (npol) {

		new = sp_alloc(vma->vm_pgoff, vma->vm_pgoff + sz, npol);

	if (pol) {

		new = sp_alloc(vma->vm_pgoff, vma->vm_pgoff + sz, pol);

		if (!new)

			return -ENOMEM;

	}

	err = shared_policy_replace(info, vma->vm_pgoff, vma->vm_pgoff+sz, new);

	err = shared_policy_replace(sp, vma->vm_pgoff, vma->vm_pgoff + sz, new);

	if (err && new)

		sp_free(new);

	return err;

}



/* Free a backing policy store on inode delete. */

void mpol_free_shared_policy(struct shared_policy *p)

void mpol_free_shared_policy(struct shared_policy *sp)

{

	struct sp_node *n;

	struct rb_node *next;



	if (!p->root.rb_node)

	if (!sp->root.rb_node)

		return;

	write_lock(&p->lock);

	next = rb_first(&p->root);

	write_lock(&sp->lock);

	next = rb_first(&sp->root);

	while (next) {

		n = rb_entry(next, struct sp_node, nd);

		next = rb_next(&n->nd);

		sp_delete(p, n);

		sp_delete(sp, n);

	}

	write_unlock(&p->lock);

	write_unlock(&sp->lock);

}



#ifdef CONFIG_NUMA_BALANCING
@@ -2854,7 +2850,6 @@ static inline void __init check_numabalancing_enable(void) 
}

#endif /* CONFIG_NUMA_BALANCING */



/* assumes fs == KERNEL_DS */

void __init numa_policy_init(void)

{

	nodemask_t interleave_nodes;
@@ -2917,7 +2912,6 @@ void numa_default_policy(void) 
/*

 * Parse and format mempolicy from/to strings

 */



static const char * const policy_modes[] =

{

	[MPOL_DEFAULT]    = "default",
@@ -2928,7 +2922,6 @@ static const char * const policy_modes[] = 
	[MPOL_PREFERRED_MANY]  = "prefer (many)",

};





#ifdef CONFIG_TMPFS

/**

 * mpol_parse_str - parse string to mempolicy, for tmpfs mpol mount option.