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

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)
void page_counter_cancel(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,
struct page_counter **fail);
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,
}
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);
done:
*ptr = h_cg;
......
......@@ -2016,8 +2016,8 @@ static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
return 0;
if (!do_swap_account ||
!page_counter_try_charge(&memcg->memsw, batch, &counter)) {
if (!page_counter_try_charge(&memcg->memory, batch, &counter))
page_counter_try_charge(&memcg->memsw, batch, &counter)) {
if (page_counter_try_charge(&memcg->memory, batch, &counter))
goto done_restock;
if (do_swap_account)
page_counter_uncharge(&memcg->memsw, batch);
......@@ -2381,14 +2381,13 @@ int __memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
{
unsigned int nr_pages = 1 << order;
struct page_counter *counter;
int ret = 0;
int ret;
if (!memcg_kmem_is_active(memcg))
return 0;
ret = page_counter_try_charge(&memcg->kmem, nr_pages, &counter);
if (ret)
return ret;
if (!page_counter_try_charge(&memcg->kmem, nr_pages, &counter))
return -ENOMEM;
ret = try_charge(memcg, gfp, nr_pages);
if (ret) {
......
......@@ -56,10 +56,10 @@ void page_counter_charge(struct page_counter *counter, unsigned long nr_pages)
* @nr_pages: number of pages to charge
* @fail: points first counter to hit its limit, if any
*
* Returns 0 on success, or -ENOMEM and @fail if the counter or one of
* its ancestors has hit its configured limit.
* Returns %true on success, or %false and @fail if the counter or one
* 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,
struct page_counter **fail)
{
......@@ -99,13 +99,13 @@ int page_counter_try_charge(struct page_counter *counter,
if (new > c->watermark)
c->watermark = new;
}
return 0;
return true;
failed:
for (c = counter; c != *fail; c = c->parent)
page_counter_cancel(c, nr_pages);
return -ENOMEM;
return false;
}
/**
......
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