mempolicy trivia: use pgoff_t in shared mempolicy tree

Prefer the more explicit "pgoff_t" to "unsigned long" when dealing with a
shared mempolicy tree.  Delete confusing comment about pseudo mm vmas.

Link: https://lkml.kernel.org/r/5451157-3818-4af5-fd2c-5d26a5d1dc53@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
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: Matthew Wilcox (Oracle) <willy@infradead.org>
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: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Hugh Dickins 2023-10-03 02:21:34 -07:00 committed by Andrew Morton
parent c36f6e6dff
commit 93397c3b76
2 changed files with 13 additions and 19 deletions

View File

@ -105,22 +105,16 @@ static inline bool mpol_equal(struct mempolicy *a, struct mempolicy *b)
/*
* Tree of shared policies for a shared memory region.
* Maintain the policies in a pseudo mm that contains vmas. The vmas
* carry the policy. As a special twist the pseudo mm is indexed in pages, not
* bytes, so that we can work with shared memory segments bigger than
* unsigned long.
*/
struct sp_node {
struct rb_node nd;
unsigned long start, end;
struct mempolicy *policy;
};
struct shared_policy {
struct rb_root root;
rwlock_t lock;
};
struct sp_node {
struct rb_node nd;
pgoff_t start, end;
struct mempolicy *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);
@ -128,7 +122,7 @@ 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);
pgoff_t idx);
struct mempolicy *get_task_policy(struct task_struct *p);
struct mempolicy *__get_vma_policy(struct vm_area_struct *vma,
@ -214,7 +208,7 @@ static inline void mpol_free_shared_policy(struct shared_policy *sp)
}
static inline struct mempolicy *
mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx)
mpol_shared_policy_lookup(struct shared_policy *sp, pgoff_t idx)
{
return NULL;
}

View File

@ -2428,8 +2428,8 @@ bool __mpol_equal(struct mempolicy *a, struct mempolicy *b)
* lookup first element intersecting start-end. Caller holds sp->lock for
* reading or for writing
*/
static struct sp_node *
sp_lookup(struct shared_policy *sp, unsigned long start, unsigned long end)
static struct sp_node *sp_lookup(struct shared_policy *sp,
pgoff_t start, pgoff_t end)
{
struct rb_node *n = sp->root.rb_node;
@ -2483,8 +2483,8 @@ static void sp_insert(struct shared_policy *sp, struct sp_node *new)
}
/* Find shared policy intersecting idx */
struct mempolicy *
mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx)
struct mempolicy *mpol_shared_policy_lookup(struct shared_policy *sp,
pgoff_t idx)
{
struct mempolicy *pol = NULL;
struct sp_node *sn;
@ -2652,8 +2652,8 @@ static struct sp_node *sp_alloc(unsigned long start, unsigned long end,
}
/* Replace a policy range. */
static int shared_policy_replace(struct shared_policy *sp, unsigned long start,
unsigned long end, struct sp_node *new)
static int shared_policy_replace(struct shared_policy *sp, pgoff_t start,
pgoff_t end, struct sp_node *new)
{
struct sp_node *n;
struct sp_node *n_new = NULL;