Commit 6071ca52 authored by Johannes Weiner's avatar Johannes Weiner Committed by Linus Torvalds

mm: page_counter: let page_counter_try_charge() return bool

page_counter_try_charge() currently returns 0 on success and -ENOMEM on
failure, which is surprising behavior given the function name.

Make it follow the expected pattern of try_stuff() functions that return a
boolean true to indicate success, or false for failure.
Signed-off-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent f5fc3c5d
...@@ -36,7 +36,7 @@ static inline unsigned long page_counter_read(struct page_counter *counter) ...@@ -36,7 +36,7 @@ static inline unsigned long page_counter_read(struct page_counter *counter)
void page_counter_cancel(struct page_counter *counter, unsigned long nr_pages); void page_counter_cancel(struct page_counter *counter, unsigned long nr_pages);
void page_counter_charge(struct page_counter *counter, unsigned long nr_pages); void page_counter_charge(struct page_counter *counter, unsigned long nr_pages);
int page_counter_try_charge(struct page_counter *counter, bool page_counter_try_charge(struct page_counter *counter,
unsigned long nr_pages, unsigned long nr_pages,
struct page_counter **fail); struct page_counter **fail);
void page_counter_uncharge(struct page_counter *counter, unsigned long nr_pages); void page_counter_uncharge(struct page_counter *counter, unsigned long nr_pages);
......
...@@ -186,7 +186,8 @@ int hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages, ...@@ -186,7 +186,8 @@ int hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages,
} }
rcu_read_unlock(); rcu_read_unlock();
ret = page_counter_try_charge(&h_cg->hugepage[idx], nr_pages, &counter); if (!page_counter_try_charge(&h_cg->hugepage[idx], nr_pages, &counter))
ret = -ENOMEM;
css_put(&h_cg->css); css_put(&h_cg->css);
done: done:
*ptr = h_cg; *ptr = h_cg;
......
...@@ -2016,8 +2016,8 @@ static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, ...@@ -2016,8 +2016,8 @@ static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
return 0; return 0;
if (!do_swap_account || if (!do_swap_account ||
!page_counter_try_charge(&memcg->memsw, batch, &counter)) { page_counter_try_charge(&memcg->memsw, batch, &counter)) {
if (!page_counter_try_charge(&memcg->memory, batch, &counter)) if (page_counter_try_charge(&memcg->memory, batch, &counter))
goto done_restock; goto done_restock;
if (do_swap_account) if (do_swap_account)
page_counter_uncharge(&memcg->memsw, batch); page_counter_uncharge(&memcg->memsw, batch);
...@@ -2381,14 +2381,13 @@ int __memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order, ...@@ -2381,14 +2381,13 @@ int __memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
{ {
unsigned int nr_pages = 1 << order; unsigned int nr_pages = 1 << order;
struct page_counter *counter; struct page_counter *counter;
int ret = 0; int ret;
if (!memcg_kmem_is_active(memcg)) if (!memcg_kmem_is_active(memcg))
return 0; return 0;
ret = page_counter_try_charge(&memcg->kmem, nr_pages, &counter); if (!page_counter_try_charge(&memcg->kmem, nr_pages, &counter))
if (ret) return -ENOMEM;
return ret;
ret = try_charge(memcg, gfp, nr_pages); ret = try_charge(memcg, gfp, nr_pages);
if (ret) { if (ret) {
......
...@@ -56,10 +56,10 @@ void page_counter_charge(struct page_counter *counter, unsigned long nr_pages) ...@@ -56,10 +56,10 @@ void page_counter_charge(struct page_counter *counter, unsigned long nr_pages)
* @nr_pages: number of pages to charge * @nr_pages: number of pages to charge
* @fail: points first counter to hit its limit, if any * @fail: points first counter to hit its limit, if any
* *
* Returns 0 on success, or -ENOMEM and @fail if the counter or one of * Returns %true on success, or %false and @fail if the counter or one
* its ancestors has hit its configured limit. * of its ancestors has hit its configured limit.
*/ */
int page_counter_try_charge(struct page_counter *counter, bool page_counter_try_charge(struct page_counter *counter,
unsigned long nr_pages, unsigned long nr_pages,
struct page_counter **fail) struct page_counter **fail)
{ {
...@@ -99,13 +99,13 @@ int page_counter_try_charge(struct page_counter *counter, ...@@ -99,13 +99,13 @@ int page_counter_try_charge(struct page_counter *counter,
if (new > c->watermark) if (new > c->watermark)
c->watermark = new; c->watermark = new;
} }
return 0; return true;
failed: failed:
for (c = counter; c != *fail; c = c->parent) for (c = counter; c != *fail; c = c->parent)
page_counter_cancel(c, nr_pages); page_counter_cancel(c, nr_pages);
return -ENOMEM; return false;
} }
/** /**
......
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