提交 7ec99d62 编写于 作者: J Johannes Weiner 提交者: Linus Torvalds

memcg: unify charge/uncharge quantities to units of pages

There is no clear pattern when we pass a page count and when we pass a
byte count that is a multiple of PAGE_SIZE.

We never charge or uncharge subpage quantities, so convert it all to page
counts.
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
上级 7ffd4ca7
......@@ -1109,16 +1109,16 @@ unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
* @mem: the memory cgroup
*
* Returns the maximum amount of memory @mem can be charged with, in
* bytes.
* pages.
*/
static unsigned long long mem_cgroup_margin(struct mem_cgroup *mem)
static unsigned long mem_cgroup_margin(struct mem_cgroup *mem)
{
unsigned long long margin;
margin = res_counter_margin(&mem->res);
if (do_swap_account)
margin = min(margin, res_counter_margin(&mem->memsw));
return margin;
return margin >> PAGE_SHIFT;
}
static unsigned int get_swappiness(struct mem_cgroup *memcg)
......@@ -1647,7 +1647,7 @@ EXPORT_SYMBOL(mem_cgroup_update_page_stat);
* size of first charge trial. "32" comes from vmscan.c's magic value.
* TODO: maybe necessary to use big numbers in big irons.
*/
#define CHARGE_SIZE (32 * PAGE_SIZE)
#define CHARGE_BATCH 32U
struct memcg_stock_pcp {
struct mem_cgroup *cached; /* this never be root cgroup */
unsigned int nr_pages;
......@@ -1822,9 +1822,10 @@ enum {
CHARGE_OOM_DIE, /* the current is killed because of OOM */
};
static int __mem_cgroup_do_charge(struct mem_cgroup *mem, gfp_t gfp_mask,
int csize, bool oom_check)
static int mem_cgroup_do_charge(struct mem_cgroup *mem, gfp_t gfp_mask,
unsigned int nr_pages, bool oom_check)
{
unsigned long csize = nr_pages * PAGE_SIZE;
struct mem_cgroup *mem_over_limit;
struct res_counter *fail_res;
unsigned long flags = 0;
......@@ -1845,14 +1846,13 @@ static int __mem_cgroup_do_charge(struct mem_cgroup *mem, gfp_t gfp_mask,
} else
mem_over_limit = mem_cgroup_from_res_counter(fail_res, res);
/*
* csize can be either a huge page (HPAGE_SIZE), a batch of
* regular pages (CHARGE_SIZE), or a single regular page
* (PAGE_SIZE).
* nr_pages can be either a huge page (HPAGE_PMD_NR), a batch
* of regular pages (CHARGE_BATCH), or a single regular page (1).
*
* Never reclaim on behalf of optional batching, retry with a
* single page instead.
*/
if (csize == CHARGE_SIZE)
if (nr_pages == CHARGE_BATCH)
return CHARGE_RETRY;
if (!(gfp_mask & __GFP_WAIT))
......@@ -1860,7 +1860,7 @@ static int __mem_cgroup_do_charge(struct mem_cgroup *mem, gfp_t gfp_mask,
ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, NULL,
gfp_mask, flags);
if (mem_cgroup_margin(mem_over_limit) >= csize)
if (mem_cgroup_margin(mem_over_limit) >= nr_pages)
return CHARGE_RETRY;
/*
* Even though the limit is exceeded at this point, reclaim
......@@ -1871,7 +1871,7 @@ static int __mem_cgroup_do_charge(struct mem_cgroup *mem, gfp_t gfp_mask,
* unlikely to succeed so close to the limit, and we fall back
* to regular pages anyway in case of failure.
*/
if (csize == PAGE_SIZE && ret)
if (nr_pages == 1 && ret)
return CHARGE_RETRY;
/*
......@@ -1897,13 +1897,14 @@ static int __mem_cgroup_do_charge(struct mem_cgroup *mem, gfp_t gfp_mask,
*/
static int __mem_cgroup_try_charge(struct mm_struct *mm,
gfp_t gfp_mask,
struct mem_cgroup **memcg, bool oom,
int page_size)
unsigned int nr_pages,
struct mem_cgroup **memcg,
bool oom)
{
unsigned int batch = max(CHARGE_BATCH, nr_pages);
int nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES;
struct mem_cgroup *mem = NULL;
int ret;
int csize = max(CHARGE_SIZE, (unsigned long) page_size);
/*
* Unlike gloval-vm's OOM-kill, we're not in memory shortage
......@@ -1928,7 +1929,7 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm,
VM_BUG_ON(css_is_removed(&mem->css));
if (mem_cgroup_is_root(mem))
goto done;
if (page_size == PAGE_SIZE && consume_stock(mem))
if (nr_pages == 1 && consume_stock(mem))
goto done;
css_get(&mem->css);
} else {
......@@ -1951,7 +1952,7 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm,
rcu_read_unlock();
goto done;
}
if (page_size == PAGE_SIZE && consume_stock(mem)) {
if (nr_pages == 1 && consume_stock(mem)) {
/*
* It seems dagerous to access memcg without css_get().
* But considering how consume_stok works, it's not
......@@ -1986,13 +1987,12 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm,
nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES;
}
ret = __mem_cgroup_do_charge(mem, gfp_mask, csize, oom_check);
ret = mem_cgroup_do_charge(mem, gfp_mask, batch, oom_check);
switch (ret) {
case CHARGE_OK:
break;
case CHARGE_RETRY: /* not in OOM situation but retry */
csize = page_size;
batch = nr_pages;
css_put(&mem->css);
mem = NULL;
goto again;
......@@ -2013,8 +2013,8 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm,
}
} while (ret != CHARGE_OK);
if (csize > page_size)
refill_stock(mem, (csize - page_size) >> PAGE_SHIFT);
if (batch > nr_pages)
refill_stock(mem, batch - nr_pages);
css_put(&mem->css);
done:
*memcg = mem;
......@@ -2093,12 +2093,10 @@ struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
static void __mem_cgroup_commit_charge(struct mem_cgroup *mem,
struct page *page,
unsigned int nr_pages,
struct page_cgroup *pc,
enum charge_type ctype,
int page_size)
enum charge_type ctype)
{
int nr_pages = page_size >> PAGE_SHIFT;
lock_page_cgroup(pc);
if (unlikely(PageCgroupUsed(pc))) {
unlock_page_cgroup(pc);
......@@ -2187,26 +2185,28 @@ void mem_cgroup_split_huge_fixup(struct page *head, struct page *tail)
/**
* mem_cgroup_move_account - move account of the page
* @page: the page
* @nr_pages: number of regular pages (>1 for huge pages)
* @pc: page_cgroup of the page.
* @from: mem_cgroup which the page is moved from.
* @to: mem_cgroup which the page is moved to. @from != @to.
* @uncharge: whether we should call uncharge and css_put against @from.
* @charge_size: number of bytes to charge (regular or huge page)
*
* The caller must confirm following.
* - page is not on LRU (isolate_page() is useful.)
* - compound_lock is held when charge_size > PAGE_SIZE
* - compound_lock is held when nr_pages > 1
*
* This function doesn't do "charge" nor css_get to new cgroup. It should be
* done by a caller(__mem_cgroup_try_charge would be usefull). If @uncharge is
* true, this function does "uncharge" from old cgroup, but it doesn't if
* @uncharge is false, so a caller should do "uncharge".
*/
static int mem_cgroup_move_account(struct page *page, struct page_cgroup *pc,
struct mem_cgroup *from, struct mem_cgroup *to,
bool uncharge, int charge_size)
static int mem_cgroup_move_account(struct page *page,
unsigned int nr_pages,
struct page_cgroup *pc,
struct mem_cgroup *from,
struct mem_cgroup *to,
bool uncharge)
{
int nr_pages = charge_size >> PAGE_SHIFT;
unsigned long flags;
int ret;
......@@ -2219,7 +2219,7 @@ static int mem_cgroup_move_account(struct page *page, struct page_cgroup *pc,
* hold it.
*/
ret = -EBUSY;
if (charge_size > PAGE_SIZE && !PageTransHuge(page))
if (nr_pages > 1 && !PageTransHuge(page))
goto out;
lock_page_cgroup(pc);
......@@ -2277,7 +2277,7 @@ static int mem_cgroup_move_parent(struct page *page,
struct cgroup *cg = child->css.cgroup;
struct cgroup *pcg = cg->parent;
struct mem_cgroup *parent;
int page_size = PAGE_SIZE;
unsigned int nr_pages;
unsigned long flags;
int ret;
......@@ -2291,23 +2291,21 @@ static int mem_cgroup_move_parent(struct page *page,
if (isolate_lru_page(page))
goto put;
if (PageTransHuge(page))
page_size = HPAGE_SIZE;
nr_pages = hpage_nr_pages(page);
parent = mem_cgroup_from_cont(pcg);
ret = __mem_cgroup_try_charge(NULL, gfp_mask,
&parent, false, page_size);
ret = __mem_cgroup_try_charge(NULL, gfp_mask, nr_pages, &parent, false);
if (ret || !parent)
goto put_back;
if (page_size > PAGE_SIZE)
if (nr_pages > 1)
flags = compound_lock_irqsave(page);
ret = mem_cgroup_move_account(page, pc, child, parent, true, page_size);
ret = mem_cgroup_move_account(page, nr_pages, pc, child, parent, true);
if (ret)
__mem_cgroup_cancel_charge(parent, page_size >> PAGE_SHIFT);
__mem_cgroup_cancel_charge(parent, nr_pages);
if (page_size > PAGE_SIZE)
if (nr_pages > 1)
compound_unlock_irqrestore(page, flags);
put_back:
putback_lru_page(page);
......@@ -2327,13 +2325,13 @@ static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
gfp_t gfp_mask, enum charge_type ctype)
{
struct mem_cgroup *mem = NULL;
int page_size = PAGE_SIZE;
unsigned int nr_pages = 1;
struct page_cgroup *pc;
bool oom = true;
int ret;
if (PageTransHuge(page)) {
page_size <<= compound_order(page);
nr_pages <<= compound_order(page);
VM_BUG_ON(!PageTransHuge(page));
/*
* Never OOM-kill a process for a huge page. The
......@@ -2345,11 +2343,11 @@ static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
pc = lookup_page_cgroup(page);
BUG_ON(!pc); /* XXX: remove this and move pc lookup into commit */
ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, oom, page_size);
ret = __mem_cgroup_try_charge(mm, gfp_mask, nr_pages, &mem, oom);
if (ret || !mem)
return ret;
__mem_cgroup_commit_charge(mem, page, pc, ctype, page_size);
__mem_cgroup_commit_charge(mem, page, nr_pages, pc, ctype);
return 0;
}
......@@ -2465,13 +2463,13 @@ int mem_cgroup_try_charge_swapin(struct mm_struct *mm,
if (!mem)
goto charge_cur_mm;
*ptr = mem;
ret = __mem_cgroup_try_charge(NULL, mask, ptr, true, PAGE_SIZE);
ret = __mem_cgroup_try_charge(NULL, mask, 1, ptr, true);
css_put(&mem->css);
return ret;
charge_cur_mm:
if (unlikely(!mm))
mm = &init_mm;
return __mem_cgroup_try_charge(mm, mask, ptr, true, PAGE_SIZE);
return __mem_cgroup_try_charge(mm, mask, 1, ptr, true);
}
static void
......@@ -2487,7 +2485,7 @@ __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
cgroup_exclude_rmdir(&ptr->css);
pc = lookup_page_cgroup(page);
mem_cgroup_lru_del_before_commit_swapcache(page);
__mem_cgroup_commit_charge(ptr, page, pc, ctype, PAGE_SIZE);
__mem_cgroup_commit_charge(ptr, page, 1, pc, ctype);
mem_cgroup_lru_add_after_commit_swapcache(page);
/*
* Now swap is on-memory. This means this page may be
......@@ -2539,12 +2537,13 @@ void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *mem)
__mem_cgroup_cancel_charge(mem, 1);
}
static void
__do_uncharge(struct mem_cgroup *mem, const enum charge_type ctype,
int page_size)
static void mem_cgroup_do_uncharge(struct mem_cgroup *mem,
unsigned int nr_pages,
const enum charge_type ctype)
{
struct memcg_batch_info *batch = NULL;
bool uncharge_memsw = true;
/* If swapout, usage of swap doesn't decrease */
if (!do_swap_account || ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT)
uncharge_memsw = false;
......@@ -2568,7 +2567,7 @@ __do_uncharge(struct mem_cgroup *mem, const enum charge_type ctype,
if (!batch->do_batch || test_thread_flag(TIF_MEMDIE))
goto direct_uncharge;
if (page_size != PAGE_SIZE)
if (nr_pages > 1)
goto direct_uncharge;
/*
......@@ -2584,9 +2583,9 @@ __do_uncharge(struct mem_cgroup *mem, const enum charge_type ctype,
batch->memsw_nr_pages++;
return;
direct_uncharge:
res_counter_uncharge(&mem->res, page_size);
res_counter_uncharge(&mem->res, nr_pages * PAGE_SIZE);
if (uncharge_memsw)
res_counter_uncharge(&mem->memsw, page_size);
res_counter_uncharge(&mem->memsw, nr_pages * PAGE_SIZE);
if (unlikely(batch->memcg != mem))
memcg_oom_recover(mem);
return;
......@@ -2598,10 +2597,9 @@ __do_uncharge(struct mem_cgroup *mem, const enum charge_type ctype,
static struct mem_cgroup *
__mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
{
int count;
struct page_cgroup *pc;
struct mem_cgroup *mem = NULL;
int page_size = PAGE_SIZE;
unsigned int nr_pages = 1;
struct page_cgroup *pc;
if (mem_cgroup_disabled())
return NULL;
......@@ -2610,11 +2608,9 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
return NULL;
if (PageTransHuge(page)) {
page_size <<= compound_order(page);
nr_pages <<= compound_order(page);
VM_BUG_ON(!PageTransHuge(page));
}
count = page_size >> PAGE_SHIFT;
/*
* Check if our page_cgroup is valid
*/
......@@ -2647,7 +2643,7 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
break;
}
mem_cgroup_charge_statistics(mem, PageCgroupCache(pc), -count);
mem_cgroup_charge_statistics(mem, PageCgroupCache(pc), -nr_pages);
ClearPageCgroupUsed(pc);
/*
......@@ -2668,7 +2664,7 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
mem_cgroup_get(mem);
}
if (!mem_cgroup_is_root(mem))
__do_uncharge(mem, ctype, page_size);
mem_cgroup_do_uncharge(mem, nr_pages, ctype);
return mem;
......@@ -2860,8 +2856,8 @@ static inline int mem_cgroup_move_swap_account(swp_entry_t entry,
int mem_cgroup_prepare_migration(struct page *page,
struct page *newpage, struct mem_cgroup **ptr, gfp_t gfp_mask)
{
struct page_cgroup *pc;
struct mem_cgroup *mem = NULL;
struct page_cgroup *pc;
enum charge_type ctype;
int ret = 0;
......@@ -2917,7 +2913,7 @@ int mem_cgroup_prepare_migration(struct page *page,
return 0;
*ptr = mem;
ret = __mem_cgroup_try_charge(NULL, gfp_mask, ptr, false, PAGE_SIZE);
ret = __mem_cgroup_try_charge(NULL, gfp_mask, 1, ptr, false);
css_put(&mem->css);/* drop extra refcnt */
if (ret || *ptr == NULL) {
if (PageAnon(page)) {
......@@ -2944,7 +2940,7 @@ int mem_cgroup_prepare_migration(struct page *page,
ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
else
ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
__mem_cgroup_commit_charge(mem, page, pc, ctype, PAGE_SIZE);
__mem_cgroup_commit_charge(mem, page, 1, pc, ctype);
return ret;
}
......@@ -4598,8 +4594,7 @@ static int mem_cgroup_do_precharge(unsigned long count)
batch_count = PRECHARGE_COUNT_AT_ONCE;
cond_resched();
}
ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false,
PAGE_SIZE);
ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, 1, &mem, false);
if (ret || !mem)
/* mem_cgroup_clear_mc() will do uncharge later */
return -ENOMEM;
......@@ -4945,8 +4940,8 @@ static int mem_cgroup_move_charge_pte_range(pmd_t *pmd,
if (isolate_lru_page(page))
goto put;
pc = lookup_page_cgroup(page);
if (!mem_cgroup_move_account(page, pc,
mc.from, mc.to, false, PAGE_SIZE)) {
if (!mem_cgroup_move_account(page, 1, pc,
mc.from, mc.to, false)) {
mc.precharge--;
/* we uncharge from mc.from later. */
mc.moved_charge++;
......
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