Re: [patch 1/3] mm: memcontrol: lockless page counters

Michal Hocko
2014-10-14T15:56:55Z

On Mon 13-10-14 21:46:01, Johannes Weiner wrote:
> Memory is internally accounted in bytes, using spinlock-protected
> 64-bit counters, even though the smallest accounting delta is a page.
> The counter interface is also convoluted and does too many things.
>
> Introduce a new lockless word-sized page counter API, then change all
> memory accounting over to it. The translation from and to bytes then
> only happens when interfacing with userspace.
>
> The removed locking overhead is noticable when scaling beyond the
> per-cpu charge caches - on a 4-socket machine with 144-threads, the
> following test shows the performance differences of 288 memcgs
> concurrently running a page fault benchmark:

I assume you had root.use_hierarchy = 1, right? Processes wouldn't bounce
on the same lock otherwise.

> vanilla:
>
> 18631648.500498 task-clock (msec) # 140.643 CPUs utilized ( +- 0.33% )
> 1,380,638 context-switches # 0.074 K/sec ( +- 0.75% )
> 24,390 cpu-migrations # 0.001 K/sec ( +- 8.44% )
> 1,843,305,768 page-faults # 0.099 M/sec ( +- 0.00% )
> 50,134,994,088,218 cycles # 2.691 GHz ( +- 0.33% )
> <not supported> stalled-cycles-frontend
> <not supported> stalled-cycles-backend
> 8,049,712,224,651 instructions # 0.16 insns per cycle ( +- 0.04% )
> 1,586,970,584,979 branches # 85.176 M/sec ( +- 0.05% )
> 1,724,989,949 branch-misses # 0.11% of all branches ( +- 0.48% )
>
> 132.474343877 seconds time elapsed ( +- 0.21% )
>
> lockless:
>
> 12195979.037525 task-clock (msec) # 133.480 CPUs utilized ( +- 0.18% )
> 832,850 context-switches # 0.068 K/sec ( +- 0.54% )
> 15,624 cpu-migrations # 0.001 K/sec ( +- 10.17% )
> 1,843,304,774 page-faults # 0.151 M/sec ( +- 0.00% )
> 32,811,216,801,141 cycles # 2.690 GHz ( +- 0.18% )
> <not supported> stalled-cycles-frontend
> <not supported> stalled-cycles-backend
> 9,999,265,091,727 instructions # 0.30 insns per cycle ( +- 0.10% )
> 2,076,759,325,203 branches # 170.282 M/sec ( +- 0.12% )
> 1,656,917,214 branch-misses # 0.08% of all branches ( +- 0.55% )
>
> 91.369330729 seconds time elapsed ( +- 0.45% )

So this is ~30% improvement which is more than I expected. Nice!
It is true that this test case is never hitting any limit so this is
always a hot-path but once we hit the limit the res_counter is the last
thing we care about.

> On top of improved scalability, this also gets rid of the icky long
> long types in the very heart of memcg, which is great for 32 bit and
> also makes the code a lot more readable.
>
> Notable differences between the old and new API:
>
> - res_counter_charge() and res_counter_charge_nofail() become
> page_counter_try_charge() and page_counter_charge() resp. to match
> the more common kernel naming scheme of try_do()/do()
>
> - res_counter_uncharge_until() is only ever used to cancel a local
> counter and never to uncharge bigger segments of a hierarchy, so
> it's replaced by the simpler page_counter_cancel()
>
> - res_counter_set_limit() is replaced by page_counter_limit(), which
> expects its callers to serialize against themselves
>
> - res_counter_memparse_write_strategy() is replaced by
> page_counter_limit(), which rounds down to the nearest page size -
> rather than up. This is more reasonable for explicitely requested
> hard upper limits.
>
> - to keep charging light-weight, page_counter_try_charge() charges
> speculatively, only to roll back if the result exceeds the limit.
> Because of this, a failing bigger charge can temporarily lock out
> smaller charges that would otherwise succeed. The error is bounded
> to the difference between the smallest and the biggest possible
> charge size, so for memcg, this means that a failing THP charge can
> send base page charges into reclaim upto 2MB (4MB) before the limit
> would have been reached. This should be acceptable.

Thanks!.

> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>

You have only missed MAINTAINERS...

Acked-by: Michal Hocko <mhocko@suse.cz>

> ---
> Documentation/cgroups/memory.txt | 4 +-
> include/linux/memcontrol.h | 5 +-
> include/linux/page_counter.h | 49 +++
> include/net/sock.h | 26 +-
> init/Kconfig | 5 +-
> mm/Makefile | 1 +
> mm/memcontrol.c | 633 ++++++++++++++++++---------------------
> mm/page_counter.c | 203 +++++++++++++
> net/ipv4/tcp_memcontrol.c | 87 +++---
> 9 files changed, 609 insertions(+), 404 deletions(-)
> create mode 100644 include/linux/page_counter.h
> create mode 100644 mm/page_counter.c
>
> diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt
> index 02ab997a1ed2..f624727ab404 100644
> --- a/Documentation/cgroups/memory.txt
> +++ b/Documentation/cgroups/memory.txt
> @@ -52,9 +52,9 @@ Brief summary of control files.
> tasks # attach a task(thread) and show list of threads
> cgroup.procs # show list of processes
> cgroup.event_control # an interface for event_fd()
> - memory.usage_in_bytes # show current res_counter usage for memory
> + memory.usage_in_bytes # show current usage for memory
> (See 5.5 for details)
> - memory.memsw.usage_in_bytes # show current res_counter usage for memory+Swap
> + memory.memsw.usage_in_bytes # show current usage for memory+Swap
> (See 5.5 for details)
> memory.limit_in_bytes # set/show limit of memory usage
> memory.memsw.limit_in_bytes # set/show limit of memory+Swap usage
> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
> index 19df5d857411..0daf383f8f1c 100644
> --- a/include/linux/memcontrol.h
> +++ b/include/linux/memcontrol.h
> @@ -471,9 +471,8 @@ memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **memcg, int order)
> /*
> * __GFP_NOFAIL allocations will move on even if charging is not
> * possible. Therefore we don't even try, and have this allocation
> - * unaccounted. We could in theory charge it with
> - * res_counter_charge_nofail, but we hope those allocations are rare,
> - * and won't be worth the trouble.
> + * unaccounted. We could in theory charge it forcibly, but we hope
> + * those allocations are rare, and won't be worth the trouble.
> */
> if (gfp & __GFP_NOFAIL)
> return true;
> diff --git a/include/linux/page_counter.h b/include/linux/page_counter.h
> new file mode 100644
> index 000000000000..d92d18949474
> --- /dev/null
> +++ b/include/linux/page_counter.h
> @@ -0,0 +1,49 @@
> +#ifndef _LINUX_PAGE_COUNTER_H
> +#define _LINUX_PAGE_COUNTER_H
> +
> +#include <linux/atomic.h>
> +
> +struct page_counter {
> + atomic_long_t count;
> + unsigned long limit;
> + struct page_counter *parent;
> +
> + /* legacy */
> + unsigned long watermark;
> + unsigned long failcnt;
> +};
> +
> +#if BITS_PER_LONG == 32
> +#define PAGE_COUNTER_MAX LONG_MAX
> +#else
> +#define PAGE_COUNTER_MAX (LONG_MAX / PAGE_SIZE)
> +#endif
> +
> +static inline void page_counter_init(struct page_counter *counter,
> + struct page_counter *parent)
> +{
> + atomic_long_set(&counter->count, 0);
> + counter->limit = PAGE_COUNTER_MAX;
> + counter->parent = parent;
> +}
> +
> +static inline unsigned long page_counter_read(struct page_counter *counter)
> +{
> + return atomic_long_read(&counter->count);
> +}
> +
> +int 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,
> + unsigned long nr_pages,
> + struct page_counter **fail);
> +int page_counter_uncharge(struct page_counter *counter, unsigned long nr_pages);
> +int page_counter_limit(struct page_counter *counter, unsigned long limit);
> +int page_counter_memparse(const char *buf, unsigned long *nr_pages);
> +
> +static inline void page_counter_reset_watermark(struct page_counter *counter)
> +{
> + counter->watermark = page_counter_read(counter);
> +}
> +
> +#endif /* _LINUX_PAGE_COUNTER_H */
> diff --git a/include/net/sock.h b/include/net/sock.h
> index 7db3db112baa..0fa8cf908b65 100644
> --- a/include/net/sock.h
> +++ b/include/net/sock.h
> @@ -54,8 +54,8 @@
> #include <linux/security.h>
> #include <linux/slab.h>
> #include <linux/uaccess.h>
> +#include <linux/page_counter.h>
> #include <linux/memcontrol.h>
> -#include <linux/res_counter.h>
> #include <linux/static_key.h>
> #include <linux/aio.h>
> #include <linux/sched.h>
> @@ -1061,7 +1061,7 @@ enum cg_proto_flags {
> };
>
> struct cg_proto {
> - struct res_counter memory_allocated; /* Current allocated memory. */
> + struct page_counter memory_allocated; /* Current allocated memory. */
> struct percpu_counter sockets_allocated; /* Current number of sockets. */
> int memory_pressure;
> long sysctl_mem[3];
> @@ -1213,34 +1213,26 @@ static inline void memcg_memory_allocated_add(struct cg_proto *prot,
> unsigned long amt,
> int *parent_status)
> {
> - struct res_counter *fail;
> - int ret;
> + page_counter_charge(&prot->memory_allocated, amt);
>
> - ret = res_counter_charge_nofail(&prot->memory_allocated,
> - amt << PAGE_SHIFT, &fail);
> - if (ret < 0)
> + if (page_counter_read(&prot->memory_allocated) >
> + prot->memory_allocated.limit)
> *parent_status = OVER_LIMIT;
> }
>
> static inline void memcg_memory_allocated_sub(struct cg_proto *prot,
> unsigned long amt)
> {
> - res_counter_uncharge(&prot->memory_allocated, amt << PAGE_SHIFT);
> -}
> -
> -static inline u64 memcg_memory_allocated_read(struct cg_proto *prot)
> -{
> - u64 ret;
> - ret = res_counter_read_u64(&prot->memory_allocated, RES_USAGE);
> - return ret >> PAGE_SHIFT;
> + page_counter_uncharge(&prot->memory_allocated, amt);
> }
>
> static inline long
> sk_memory_allocated(const struct sock *sk)
> {
> struct proto *prot = sk->sk_prot;
> +
> if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
> - return memcg_memory_allocated_read(sk->sk_cgrp);
> + return page_counter_read(&sk->sk_cgrp->memory_allocated);
>
> return atomic_long_read(prot->memory_allocated);
> }
> @@ -1254,7 +1246,7 @@ sk_memory_allocated_add(struct sock *sk, int amt, int *parent_status)
> memcg_memory_allocated_add(sk->sk_cgrp, amt, parent_status);
> /* update the root cgroup regardless */
> atomic_long_add_return(amt, prot->memory_allocated);
> - return memcg_memory_allocated_read(sk->sk_cgrp);
> + return page_counter_read(&sk->sk_cgrp->memory_allocated);
> }
>
> return atomic_long_add_return(amt, prot->memory_allocated);
> diff --git a/init/Kconfig b/init/Kconfig
> index b454b162d2df..3fc577e9de75 100644
> --- a/init/Kconfig
> +++ b/init/Kconfig
> @@ -985,9 +985,12 @@ config RESOURCE_COUNTERS
> This option enables controller independent resource accounting
> infrastructure that works with cgroups.
>
> +config PAGE_COUNTER
> + bool
> +
> config MEMCG
> bool "Memory Resource Controller for Control Groups"
> - depends on RESOURCE_COUNTERS
> + select PAGE_COUNTER
> select EVENTFD
> help
> Provides a memory resource controller that manages both anonymous
> diff --git a/mm/Makefile b/mm/Makefile
> index ba3ec4e1a66e..27ddb80403a9 100644
> --- a/mm/Makefile
> +++ b/mm/Makefile
> @@ -55,6 +55,7 @@ obj-$(CONFIG_FS_XIP) += filemap_xip.o
> obj-$(CONFIG_MIGRATION) += migrate.o
> obj-$(CONFIG_QUICKLIST) += quicklist.o
> obj-$(CONFIG_TRANSPARENT_HUGEPAGE) += huge_memory.o
> +obj-$(CONFIG_PAGE_COUNTER) += page_counter.o
> obj-$(CONFIG_MEMCG) += memcontrol.o page_cgroup.o vmpressure.o
> obj-$(CONFIG_CGROUP_HUGETLB) += hugetlb_cgroup.o
> obj-$(CONFIG_MEMORY_FAILURE) += memory-failure.o
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 23976fd885fd..b62972c80055 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -25,7 +25,7 @@
> * GNU General Public License for more details.
> */
>
> -#include <linux/res_counter.h>
> +#include <linux/page_counter.h>
> #include <linux/memcontrol.h>
> #include <linux/cgroup.h>
> #include <linux/mm.h>
> @@ -165,7 +165,7 @@ struct mem_cgroup_per_zone {
> struct mem_cgroup_reclaim_iter reclaim_iter[DEF_PRIORITY + 1];
>
> struct rb_node tree_node; /* RB tree node */
> - unsigned long long usage_in_excess;/* Set to the value by which */
> + unsigned long usage_in_excess;/* Set to the value by which */
> /* the soft limit is exceeded*/
> bool on_tree;
> struct mem_cgroup *memcg; /* Back pointer, we cannot */
> @@ -198,7 +198,7 @@ static struct mem_cgroup_tree soft_limit_tree __read_mostly;
>
> struct mem_cgroup_threshold {
> struct eventfd_ctx *eventfd;
> - u64 threshold;
> + unsigned long threshold;
> };
>
> /* For threshold */
> @@ -284,10 +284,13 @@ static void mem_cgroup_oom_notify(struct mem_cgroup *memcg);
> */
> struct mem_cgroup {
> struct cgroup_subsys_state css;
> - /*
> - * the counter to account for memory usage
> - */
> - struct res_counter res;
> +
> + /* Accounted resources */
> + struct page_counter memory;
> + struct page_counter memsw;
> + struct page_counter kmem;
> +
> + unsigned long soft_limit;
>
> /* vmpressure notifications */
> struct vmpressure vmpressure;
> @@ -296,15 +299,6 @@ struct mem_cgroup {
> int initialized;
>
> /*
> - * the counter to account for mem+swap usage.
> - */
> - struct res_counter memsw;
> -
> - /*
> - * the counter to account for kernel memory usage.
> - */
> - struct res_counter kmem;
> - /*
> * Should the accounting and control be hierarchical, per subtree?
> */
> bool use_hierarchy;
> @@ -650,7 +644,7 @@ static void disarm_kmem_keys(struct mem_cgroup *memcg)
> * This check can't live in kmem destruction function,
> * since the charges will outlive the cgroup
> */
> - WARN_ON(res_counter_read_u64(&memcg->kmem, RES_USAGE) != 0);
> + WARN_ON(page_counter_read(&memcg->kmem));
> }
> #else
> static void disarm_kmem_keys(struct mem_cgroup *memcg)
> @@ -706,7 +700,7 @@ soft_limit_tree_from_page(struct page *page)
>
> static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_zone *mz,
> struct mem_cgroup_tree_per_zone *mctz,
> - unsigned long long new_usage_in_excess)
> + unsigned long new_usage_in_excess)
> {
> struct rb_node **p = &mctz->rb_root.rb_node;
> struct rb_node *parent = NULL;
> @@ -755,10 +749,21 @@ static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_zone *mz,
> spin_unlock_irqrestore(&mctz->lock, flags);
> }
>
> +static unsigned long soft_limit_excess(struct mem_cgroup *memcg)
> +{
> + unsigned long nr_pages = page_counter_read(&memcg->memory);
> + unsigned long soft_limit = ACCESS_ONCE(memcg->soft_limit);
> + unsigned long excess = 0;
> +
> + if (nr_pages > soft_limit)
> + excess = nr_pages - soft_limit;
> +
> + return excess;
> +}
>
> static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page)
> {
> - unsigned long long excess;
> + unsigned long excess;
> struct mem_cgroup_per_zone *mz;
> struct mem_cgroup_tree_per_zone *mctz;
>
> @@ -769,7 +774,7 @@ static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page)
> */
> for (; memcg; memcg = parent_mem_cgroup(memcg)) {
> mz = mem_cgroup_page_zoneinfo(memcg, page);
> - excess = res_counter_soft_limit_excess(&memcg->res);
> + excess = soft_limit_excess(memcg);
> /*
> * We have to update the tree if mz is on RB-tree or
> * mem is over its softlimit.
> @@ -825,7 +830,7 @@ retry:
> * position in the tree.
> */
> __mem_cgroup_remove_exceeded(mz, mctz);
> - if (!res_counter_soft_limit_excess(&mz->memcg->res) ||
> + if (!soft_limit_excess(mz->memcg) ||
> !css_tryget_online(&mz->memcg->css))
> goto retry;
> done:
> @@ -1492,7 +1497,7 @@ int mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec)
> return inactive * inactive_ratio < active;
> }
>
> -#define mem_cgroup_from_res_counter(counter, member) \
> +#define mem_cgroup_from_counter(counter, member) \
> container_of(counter, struct mem_cgroup, member)
>
> /**
> @@ -1504,12 +1509,23 @@ int mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec)
> */
> static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg)
> {
> - unsigned long long margin;
> + unsigned long margin = 0;
> + unsigned long count;
> + unsigned long limit;
>
> - margin = res_counter_margin(&memcg->res);
> - if (do_swap_account)
> - margin = min(margin, res_counter_margin(&memcg->memsw));
> - return margin >> PAGE_SHIFT;
> + count = page_counter_read(&memcg->memory);
> + limit = ACCESS_ONCE(memcg->memory.limit);
> + if (count < limit)
> + margin = limit - count;
> +
> + if (do_swap_account) {
> + count = page_counter_read(&memcg->memsw);
> + limit = ACCESS_ONCE(memcg->memsw.limit);
> + if (count <= limit)
> + margin = min(margin, limit - count);
> + }
> +
> + return margin;
> }
>
> int mem_cgroup_swappiness(struct mem_cgroup *memcg)
> @@ -1650,18 +1666,15 @@ void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
>
> rcu_read_unlock();
>
> - pr_info("memory: usage %llukB, limit %llukB, failcnt %llu\n",
> - res_counter_read_u64(&memcg->res, RES_USAGE) >> 10,
> - res_counter_read_u64(&memcg->res, RES_LIMIT) >> 10,
> - res_counter_read_u64(&memcg->res, RES_FAILCNT));
> - pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %llu\n",
> - res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10,
> - res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10,
> - res_counter_read_u64(&memcg->memsw, RES_FAILCNT));
> - pr_info("kmem: usage %llukB, limit %llukB, failcnt %llu\n",
> - res_counter_read_u64(&memcg->kmem, RES_USAGE) >> 10,
> - res_counter_read_u64(&memcg->kmem, RES_LIMIT) >> 10,
> - res_counter_read_u64(&memcg->kmem, RES_FAILCNT));
> + pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n",
> + K((u64)page_counter_read(&memcg->memory)),
> + K((u64)memcg->memory.limit), memcg->memory.failcnt);
> + pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n",
> + K((u64)page_counter_read(&memcg->memsw)),
> + K((u64)memcg->memsw.limit), memcg->memsw.failcnt);
> + pr_info("kmem: usage %llukB, limit %llukB, failcnt %lu\n",
> + K((u64)page_counter_read(&memcg->kmem)),
> + K((u64)memcg->kmem.limit), memcg->kmem.failcnt);
>
> for_each_mem_cgroup_tree(iter, memcg) {
> pr_info("Memory cgroup stats for ");
> @@ -1701,28 +1714,17 @@ static int mem_cgroup_count_children(struct mem_cgroup *memcg)
> /*
> * Return the memory (and swap, if configured) limit for a memcg.
> */
> -static u64 mem_cgroup_get_limit(struct mem_cgroup *memcg)
> +static unsigned long mem_cgroup_get_limit(struct mem_cgroup *memcg)
> {
> - u64 limit;
> + unsigned long limit;
>
> - limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
> -
> - /*
> - * Do not consider swap space if we cannot swap due to swappiness
> - */
> + limit = memcg->memory.limit;
> if (mem_cgroup_swappiness(memcg)) {
> - u64 memsw;
> + unsigned long memsw_limit;
>
> - limit += total_swap_pages << PAGE_SHIFT;
> - memsw = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
> -
> - /*
> - * If memsw is finite and limits the amount of swap space
> - * available to this memcg, return that limit.
> - */
> - limit = min(limit, memsw);
> + memsw_limit = memcg->memsw.limit;
> + limit = min(limit + total_swap_pages, memsw_limit);
> }
> -
> return limit;
> }
>
> @@ -1746,7 +1748,7 @@ static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
> }
>
> check_panic_on_oom(CONSTRAINT_MEMCG, gfp_mask, order, NULL);
> - totalpages = mem_cgroup_get_limit(memcg) >> PAGE_SHIFT ? : 1;
> + totalpages = mem_cgroup_get_limit(memcg) ? : 1;
> for_each_mem_cgroup_tree(iter, memcg) {
> struct css_task_iter it;
> struct task_struct *task;
> @@ -1949,7 +1951,7 @@ static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg,
> .priority = 0,
> };
>
> - excess = res_counter_soft_limit_excess(&root_memcg->res) >> PAGE_SHIFT;
> + excess = soft_limit_excess(root_memcg);
>
> while (1) {
> victim = mem_cgroup_iter(root_memcg, victim, &reclaim);
> @@ -1980,7 +1982,7 @@ static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg,
> total += mem_cgroup_shrink_node_zone(victim, gfp_mask, false,
> zone, &nr_scanned);
> *total_scanned += nr_scanned;
> - if (!res_counter_soft_limit_excess(&root_memcg->res))
> + if (!soft_limit_excess(root_memcg))
> break;
> }
> mem_cgroup_iter_break(root_memcg, victim);
> @@ -2307,33 +2309,31 @@ static DEFINE_MUTEX(percpu_charge_mutex);
> static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
> {
> struct memcg_stock_pcp *stock;
> - bool ret = true;
> + bool ret = false;
>
> if (nr_pages > CHARGE_BATCH)
> - return false;
> + return ret;
>
> stock = &get_cpu_var(memcg_stock);
> - if (memcg == stock->cached && stock->nr_pages >= nr_pages)
> + if (memcg == stock->cached && stock->nr_pages >= nr_pages) {
> stock->nr_pages -= nr_pages;
> - else /* need to call res_counter_charge */
> - ret = false;
> + ret = true;
> + }
> put_cpu_var(memcg_stock);
> return ret;
> }
>
> /*
> - * Returns stocks cached in percpu to res_counter and reset cached information.
> + * Returns stocks cached in percpu and reset cached information.
> */
> static void drain_stock(struct memcg_stock_pcp *stock)
> {
> struct mem_cgroup *old = stock->cached;
>
> if (stock->nr_pages) {
> - unsigned long bytes = stock->nr_pages * PAGE_SIZE;
> -
> - res_counter_uncharge(&old->res, bytes);
> + page_counter_uncharge(&old->memory, stock->nr_pages);
> if (do_swap_account)
> - res_counter_uncharge(&old->memsw, bytes);
> + page_counter_uncharge(&old->memsw, stock->nr_pages);
> stock->nr_pages = 0;
> }
> stock->cached = NULL;
> @@ -2362,7 +2362,7 @@ static void __init memcg_stock_init(void)
> }
>
> /*
> - * Cache charges(val) which is from res_counter, to local per_cpu area.
> + * Cache charges(val) to local per_cpu area.
> * This will be consumed by consume_stock() function, later.
> */
> static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
> @@ -2422,8 +2422,7 @@ out:
> /*
> * Tries to drain stocked charges in other cpus. This function is asynchronous
> * and just put a work per cpu for draining localy on each cpu. Caller can
> - * expects some charges will be back to res_counter later but cannot wait for
> - * it.
> + * expects some charges will be back later but cannot wait for it.
> */
> static void drain_all_stock_async(struct mem_cgroup *root_memcg)
> {
> @@ -2497,9 +2496,8 @@ static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
> unsigned int batch = max(CHARGE_BATCH, nr_pages);
> int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
> struct mem_cgroup *mem_over_limit;
> - struct res_counter *fail_res;
> + struct page_counter *counter;
> unsigned long nr_reclaimed;
> - unsigned long long size;
> bool may_swap = true;
> bool drained = false;
> int ret = 0;
> @@ -2510,16 +2508,15 @@ retry:
> if (consume_stock(memcg, nr_pages))
> goto done;
>
> - size = batch * PAGE_SIZE;
> if (!do_swap_account ||
> - !res_counter_charge(&memcg->memsw, size, &fail_res)) {
> - if (!res_counter_charge(&memcg->res, size, &fail_res))
> + !page_counter_try_charge(&memcg->memsw, batch, &counter)) {
> + if (!page_counter_try_charge(&memcg->memory, batch, &counter))
> goto done_restock;
> if (do_swap_account)
> - res_counter_uncharge(&memcg->memsw, size);
> - mem_over_limit = mem_cgroup_from_res_counter(fail_res, res);
> + page_counter_uncharge(&memcg->memsw, batch);
> + mem_over_limit = mem_cgroup_from_counter(counter, memory);
> } else {
> - mem_over_limit = mem_cgroup_from_res_counter(fail_res, memsw);
> + mem_over_limit = mem_cgroup_from_counter(counter, memsw);
> may_swap = false;
> }
>
> @@ -2602,32 +2599,12 @@ done:
>
> static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages)
> {
> - unsigned long bytes = nr_pages * PAGE_SIZE;
> -
> if (mem_cgroup_is_root(memcg))
> return;
>
> - res_counter_uncharge(&memcg->res, bytes);
> + page_counter_uncharge(&memcg->memory, nr_pages);
> if (do_swap_account)
> - res_counter_uncharge(&memcg->memsw, bytes);
> -}
> -
> -/*
> - * Cancel chrages in this cgroup....doesn't propagate to parent cgroup.
> - * This is useful when moving usage to parent cgroup.
> - */
> -static void __mem_cgroup_cancel_local_charge(struct mem_cgroup *memcg,
> - unsigned int nr_pages)
> -{
> - unsigned long bytes = nr_pages * PAGE_SIZE;
> -
> - if (mem_cgroup_is_root(memcg))
> - return;
> -
> - res_counter_uncharge_until(&memcg->res, memcg->res.parent, bytes);
> - if (do_swap_account)
> - res_counter_uncharge_until(&memcg->memsw,
> - memcg->memsw.parent, bytes);
> + page_counter_uncharge(&memcg->memsw, nr_pages);
> }
>
> /*
> @@ -2751,8 +2728,6 @@ static void commit_charge(struct page *page, struct mem_cgroup *memcg,
> unlock_page_lru(page, isolated);
> }
>
> -static DEFINE_MUTEX(set_limit_mutex);
> -
> #ifdef CONFIG_MEMCG_KMEM
> /*
> * The memcg_slab_mutex is held whenever a per memcg kmem cache is created or
> @@ -2795,16 +2770,17 @@ static int mem_cgroup_slabinfo_read(struct seq_file *m, void *v)
> }
> #endif
>
> -static int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp, u64 size)
> +static int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp,
> + unsigned long nr_pages)
> {
> - struct res_counter *fail_res;
> + struct page_counter *counter;
> int ret = 0;
>
> - ret = res_counter_charge(&memcg->kmem, size, &fail_res);
> - if (ret)
> + ret = page_counter_try_charge(&memcg->kmem, nr_pages, &counter);
> + if (ret < 0)
> return ret;
>
> - ret = try_charge(memcg, gfp, size >> PAGE_SHIFT);
> + ret = try_charge(memcg, gfp, nr_pages);
> if (ret == -EINTR) {
> /*
> * try_charge() chose to bypass to root due to OOM kill or
> @@ -2821,25 +2797,25 @@ static int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp, u64 size)
> * when the allocation triggers should have been already
> * directed to the root cgroup in memcontrol.h
> */
> - res_counter_charge_nofail(&memcg->res, size, &fail_res);
> + page_counter_charge(&memcg->memory, nr_pages);
> if (do_swap_account)
> - res_counter_charge_nofail(&memcg->memsw, size,
> - &fail_res);
> + page_counter_charge(&memcg->memsw, nr_pages);
> ret = 0;
> } else if (ret)
> - res_counter_uncharge(&memcg->kmem, size);
> + page_counter_uncharge(&memcg->kmem, nr_pages);
>
> return ret;
> }
>
> -static void memcg_uncharge_kmem(struct mem_cgroup *memcg, u64 size)
> +static void memcg_uncharge_kmem(struct mem_cgroup *memcg,
> + unsigned long nr_pages)
> {
> - res_counter_uncharge(&memcg->res, size);
> + page_counter_uncharge(&memcg->memory, nr_pages);
> if (do_swap_account)
> - res_counter_uncharge(&memcg->memsw, size);
> + page_counter_uncharge(&memcg->memsw, nr_pages);
>
> /* Not down to 0 */
> - if (res_counter_uncharge(&memcg->kmem, size))
> + if (page_counter_uncharge(&memcg->kmem, nr_pages))
> return;
>
> /*
> @@ -3115,19 +3091,21 @@ static void memcg_schedule_register_cache(struct mem_cgroup *memcg,
>
> int __memcg_charge_slab(struct kmem_cache *cachep, gfp_t gfp, int order)
> {
> + unsigned int nr_pages = 1 << order;
> int res;
>
> - res = memcg_charge_kmem(cachep->memcg_params->memcg, gfp,
> - PAGE_SIZE << order);
> + res = memcg_charge_kmem(cachep->memcg_params->memcg, gfp, nr_pages);
> if (!res)
> - atomic_add(1 << order, &cachep->memcg_params->nr_pages);
> + atomic_add(nr_pages, &cachep->memcg_params->nr_pages);
> return res;
> }
>
> void __memcg_uncharge_slab(struct kmem_cache *cachep, int order)
> {
> - memcg_uncharge_kmem(cachep->memcg_params->memcg, PAGE_SIZE << order);
> - atomic_sub(1 << order, &cachep->memcg_params->nr_pages);
> + unsigned int nr_pages = 1 << order;
> +
> + memcg_uncharge_kmem(cachep->memcg_params->memcg, nr_pages);
> + atomic_sub(nr_pages, &cachep->memcg_params->nr_pages);
> }
>
> /*
> @@ -3248,7 +3226,7 @@ __memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **_memcg, int order)
> return true;
> }
>
> - ret = memcg_charge_kmem(memcg, gfp, PAGE_SIZE << order);
> + ret = memcg_charge_kmem(memcg, gfp, 1 << order);
> if (!ret)
> *_memcg = memcg;
>
> @@ -3265,7 +3243,7 @@ void __memcg_kmem_commit_charge(struct page *page, struct mem_cgroup *memcg,
>
> /* The page allocation failed. Revert */
> if (!page) {
> - memcg_uncharge_kmem(memcg, PAGE_SIZE << order);
> + memcg_uncharge_kmem(memcg, 1 << order);
> return;
> }
> /*
> @@ -3298,7 +3276,7 @@ void __memcg_kmem_uncharge_pages(struct page *page, int order)
> return;
>
> VM_BUG_ON_PAGE(mem_cgroup_is_root(memcg), page);
> - memcg_uncharge_kmem(memcg, PAGE_SIZE << order);
> + memcg_uncharge_kmem(memcg, 1 << order);
> }
> #else
> static inline void memcg_unregister_all_caches(struct mem_cgroup *memcg)
> @@ -3476,8 +3454,12 @@ static int mem_cgroup_move_parent(struct page *page,
>
> ret = mem_cgroup_move_account(page, nr_pages,
> pc, child, parent);
> - if (!ret)
> - __mem_cgroup_cancel_local_charge(child, nr_pages);
> + if (!ret) {
> + /* Take charge off the local counters */
> + page_counter_cancel(&child->memory, nr_pages);
> + if (do_swap_account)
> + page_counter_cancel(&child->memsw, nr_pages);
> + }
>
> if (nr_pages > 1)
> compound_unlock_irqrestore(page, flags);
> @@ -3507,7 +3489,7 @@ static void mem_cgroup_swap_statistics(struct mem_cgroup *memcg,
> *
> * Returns 0 on success, -EINVAL on failure.
> *
> - * The caller must have charged to @to, IOW, called res_counter_charge() about
> + * The caller must have charged to @to, IOW, called page_counter_charge() about
> * both res and memsw, and called css_get().
> */
> static int mem_cgroup_move_swap_account(swp_entry_t entry,
> @@ -3523,7 +3505,7 @@ static int mem_cgroup_move_swap_account(swp_entry_t entry,
> mem_cgroup_swap_statistics(to, true);
> /*
> * This function is only called from task migration context now.
> - * It postpones res_counter and refcount handling till the end
> + * It postpones page_counter and refcount handling till the end
> * of task migration(mem_cgroup_clear_mc()) for performance
> * improvement. But we cannot postpone css_get(to) because if
> * the process that has been moved to @to does swap-in, the
> @@ -3581,60 +3563,57 @@ void mem_cgroup_print_bad_page(struct page *page)
> }
> #endif
>
> +static DEFINE_MUTEX(memcg_limit_mutex);
> +
> static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
> - unsigned long long val)
> + unsigned long limit)
> {
> + unsigned long curusage;
> + unsigned long oldusage;
> + bool enlarge = false;
> int retry_count;
> - int ret = 0;
> - int children = mem_cgroup_count_children(memcg);
> - u64 curusage, oldusage;
> - int enlarge;
> + int ret;
>
> /*
> * For keeping hierarchical_reclaim simple, how long we should retry
> * is depends on callers. We set our retry-count to be function
> * of # of children which we should visit in this loop.
> */
> - retry_count = MEM_CGROUP_RECLAIM_RETRIES * children;
> + retry_count = MEM_CGROUP_RECLAIM_RETRIES *
> + mem_cgroup_count_children(memcg);
>
> - oldusage = res_counter_read_u64(&memcg->res, RES_USAGE);
> + oldusage = page_counter_read(&memcg->memory);
>
> - enlarge = 0;
> - while (retry_count) {
> + do {
> if (signal_pending(current)) {
> ret = -EINTR;
> break;
> }
> - /*
> - * Rather than hide all in some function, I do this in
> - * open coded manner. You see what this really does.
> - * We have to guarantee memcg->res.limit <= memcg->memsw.limit.
> - */
> - mutex_lock(&set_limit_mutex);
> - if (res_counter_read_u64(&memcg->memsw, RES_LIMIT) < val) {
> +
> + mutex_lock(&memcg_limit_mutex);
> + if (limit > memcg->memsw.limit) {
> + mutex_unlock(&memcg_limit_mutex);
> ret = -EINVAL;
> - mutex_unlock(&set_limit_mutex);
> break;
> }
> -
> - if (res_counter_read_u64(&memcg->res, RES_LIMIT) < val)
> - enlarge = 1;
> -
> - ret = res_counter_set_limit(&memcg->res, val);
> - mutex_unlock(&set_limit_mutex);
> + if (limit > memcg->memory.limit)
> + enlarge = true;
> + ret = page_counter_limit(&memcg->memory, limit);
> + mutex_unlock(&memcg_limit_mutex);
>
> if (!ret)
> break;
>
> try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, true);
>
> - curusage = res_counter_read_u64(&memcg->res, RES_USAGE);
> + curusage = page_counter_read(&memcg->memory);
> /* Usage is reduced ? */
> if (curusage >= oldusage)
> retry_count--;
> else
> oldusage = curusage;
> - }
> + } while (retry_count);
> +
> if (!ret && enlarge)
> memcg_oom_recover(memcg);
>
> @@ -3642,52 +3621,53 @@ static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
> }
>
> static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
> - unsigned long long val)
> + unsigned long limit)
> {
> + unsigned long curusage;
> + unsigned long oldusage;
> + bool enlarge = false;
> int retry_count;
> - u64 oldusage, curusage;
> - int children = mem_cgroup_count_children(memcg);
> - int ret = -EBUSY;
> - int enlarge = 0;
> + int ret;
>
> /* see mem_cgroup_resize_res_limit */
> - retry_count = children * MEM_CGROUP_RECLAIM_RETRIES;
> - oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
> - while (retry_count) {
> + retry_count = MEM_CGROUP_RECLAIM_RETRIES *
> + mem_cgroup_count_children(memcg);
> +
> + oldusage = page_counter_read(&memcg->memsw);
> +
> + do {
> if (signal_pending(current)) {
> ret = -EINTR;
> break;
> }
> - /*
> - * Rather than hide all in some function, I do this in
> - * open coded manner. You see what this really does.
> - * We have to guarantee memcg->res.limit <= memcg->memsw.limit.
> - */
> - mutex_lock(&set_limit_mutex);
> - if (res_counter_read_u64(&memcg->res, RES_LIMIT) > val) {
> +
> + mutex_lock(&memcg_limit_mutex);
> + if (limit < memcg->memory.limit) {
> + mutex_unlock(&memcg_limit_mutex);
> ret = -EINVAL;
> - mutex_unlock(&set_limit_mutex);
> break;
> }
> - if (res_counter_read_u64(&memcg->memsw, RES_LIMIT) < val)
> - enlarge = 1;
> - ret = res_counter_set_limit(&memcg->memsw, val);
> - mutex_unlock(&set_limit_mutex);
> + if (limit > memcg->memsw.limit)
> + enlarge = true;
> + ret = page_counter_limit(&memcg->memsw, limit);
> + mutex_unlock(&memcg_limit_mutex);
>
> if (!ret)
> break;
>
> try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, false);
>
> - curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
> + curusage = page_counter_read(&memcg->memsw);
> /* Usage is reduced ? */
> if (curusage >= oldusage)
> retry_count--;
> else
> oldusage = curusage;
> - }
> + } while (retry_count);
> +
> if (!ret && enlarge)
> memcg_oom_recover(memcg);
> +
> return ret;
> }
>
> @@ -3700,7 +3680,7 @@ unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
> unsigned long reclaimed;
> int loop = 0;
> struct mem_cgroup_tree_per_zone *mctz;
> - unsigned long long excess;
> + unsigned long excess;
> unsigned long nr_scanned;
>
> if (order > 0)
> @@ -3754,7 +3734,7 @@ unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
> } while (1);
> }
> __mem_cgroup_remove_exceeded(mz, mctz);
> - excess = res_counter_soft_limit_excess(&mz->memcg->res);
> + excess = soft_limit_excess(mz->memcg);
> /*
> * One school of thought says that we should not add
> * back the node to the tree if reclaim returns 0.
> @@ -3847,7 +3827,6 @@ static void mem_cgroup_force_empty_list(struct mem_cgroup *memcg,
> static void mem_cgroup_reparent_charges(struct mem_cgroup *memcg)
> {
> int node, zid;
> - u64 usage;
>
> do {
> /* This is for making all *used* pages to be on LRU. */
> @@ -3879,9 +3858,8 @@ static void mem_cgroup_reparent_charges(struct mem_cgroup *memcg)
> * right after the check. RES_USAGE should be safe as we always
> * charge before adding to the LRU.
> */
> - usage = res_counter_read_u64(&memcg->res, RES_USAGE) -
> - res_counter_read_u64(&memcg->kmem, RES_USAGE);
> - } while (usage > 0);
> + } while (page_counter_read(&memcg->memory) -
> + page_counter_read(&memcg->kmem) > 0);
> }
>
> /*
> @@ -3921,7 +3899,7 @@ static int mem_cgroup_force_empty(struct mem_cgroup *memcg)
> /* we call try-to-free pages for make this cgroup empty */
> lru_add_drain_all();
> /* try to free all pages in this cgroup */
> - while (nr_retries && res_counter_read_u64(&memcg->res, RES_USAGE) > 0) {
> + while (nr_retries && page_counter_read(&memcg->memory)) {
> int progress;
>
> if (signal_pending(current))
> @@ -3992,8 +3970,8 @@ out:
> return retval;
> }
>
> -static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup *memcg,
> - enum mem_cgroup_stat_index idx)
> +static unsigned long tree_stat(struct mem_cgroup *memcg,
> + enum mem_cgroup_stat_index idx)
> {
> struct mem_cgroup *iter;
> long val = 0;
> @@ -4011,55 +3989,72 @@ static inline u64 mem_cgroup_usage(struct mem_cgroup *memcg, bool swap)
> {
> u64 val;
>
> - if (!mem_cgroup_is_root(memcg)) {
> + if (mem_cgroup_is_root(memcg)) {
> + val = tree_stat(memcg, MEM_CGROUP_STAT_CACHE);
> + val += tree_stat(memcg, MEM_CGROUP_STAT_RSS);
> + if (swap)
> + val += tree_stat(memcg, MEM_CGROUP_STAT_SWAP);
> + } else {
> if (!swap)
> - return res_counter_read_u64(&memcg->res, RES_USAGE);
> + val = page_counter_read(&memcg->memory);
> else
> - return res_counter_read_u64(&memcg->memsw, RES_USAGE);
> + val = page_counter_read(&memcg->memsw);
> }
> -
> - /*
> - * Transparent hugepages are still accounted for in MEM_CGROUP_STAT_RSS
> - * as well as in MEM_CGROUP_STAT_RSS_HUGE.
> - */
> - val = mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_CACHE);
> - val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_RSS);
> -
> - if (swap)
> - val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_SWAP);
> -
> return val << PAGE_SHIFT;
> }
>
> +enum {
> + RES_USAGE,
> + RES_LIMIT,
> + RES_MAX_USAGE,
> + RES_FAILCNT,
> + RES_SOFT_LIMIT,
> +};
>
> static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css,
> struct cftype *cft)
> {
> struct mem_cgroup *memcg = mem_cgroup_from_css(css);
> - enum res_type type = MEMFILE_TYPE(cft->private);
> - int name = MEMFILE_ATTR(cft->private);
> + struct page_counter *counter;
>
> - switch (type) {
> + switch (MEMFILE_TYPE(cft->private)) {
> case _MEM:
> - if (name == RES_USAGE)
> - return mem_cgroup_usage(memcg, false);
> - return res_counter_read_u64(&memcg->res, name);
> + counter = &memcg->memory;
> + break;
> case _MEMSWAP:
> - if (name == RES_USAGE)
> - return mem_cgroup_usage(memcg, true);
> - return res_counter_read_u64(&memcg->memsw, name);
> + counter = &memcg->memsw;
> + break;
> case _KMEM:
> - return res_counter_read_u64(&memcg->kmem, name);
> + counter = &memcg->kmem;
> break;
> default:
> BUG();
> }
> +
> + switch (MEMFILE_ATTR(cft->private)) {
> + case RES_USAGE:
> + if (counter == &memcg->memory)
> + return mem_cgroup_usage(memcg, false);
> + if (counter == &memcg->memsw)
> + return mem_cgroup_usage(memcg, true);
> + return (u64)page_counter_read(counter) * PAGE_SIZE;
> + case RES_LIMIT:
> + return (u64)counter->limit * PAGE_SIZE;
> + case RES_MAX_USAGE:
> + return (u64)counter->watermark * PAGE_SIZE;
> + case RES_FAILCNT:
> + return counter->failcnt;
> + case RES_SOFT_LIMIT:
> + return (u64)memcg->soft_limit * PAGE_SIZE;
> + default:
> + BUG();
> + }
> }
>
> #ifdef CONFIG_MEMCG_KMEM
> /* should be called with activate_kmem_mutex held */
> static int __memcg_activate_kmem(struct mem_cgroup *memcg,
> - unsigned long long limit)
> + unsigned long nr_pages)
> {
> int err = 0;
> int memcg_id;
> @@ -4106,7 +4101,7 @@ static int __memcg_activate_kmem(struct mem_cgroup *memcg,
> * We couldn't have accounted to this cgroup, because it hasn't got the
> * active bit set yet, so this should succeed.
> */
> - err = res_counter_set_limit(&memcg->kmem, limit);
> + err = page_counter_limit(&memcg->kmem, nr_pages);
> VM_BUG_ON(err);
>
> static_key_slow_inc(&memcg_kmem_enabled_key);
> @@ -4122,25 +4117,27 @@ out:
> }
>
> static int memcg_activate_kmem(struct mem_cgroup *memcg,
> - unsigned long long limit)
> + unsigned long nr_pages)
> {
> int ret;
>
> mutex_lock(&activate_kmem_mutex);
> - ret = __memcg_activate_kmem(memcg, limit);
> + ret = __memcg_activate_kmem(memcg, nr_pages);
> mutex_unlock(&activate_kmem_mutex);
> return ret;
> }
>
> static int memcg_update_kmem_limit(struct mem_cgroup *memcg,
> - unsigned long long val)
> + unsigned long limit)
> {
> int ret;
>
> + mutex_lock(&memcg_limit_mutex);
> if (!memcg_kmem_is_active(memcg))
> - ret = memcg_activate_kmem(memcg, val);
> + ret = memcg_activate_kmem(memcg, limit);
> else
> - ret = res_counter_set_limit(&memcg->kmem, val);
> + ret = page_counter_limit(&memcg->kmem, limit);
> + mutex_unlock(&memcg_limit_mutex);
> return ret;
> }
>
> @@ -4158,13 +4155,13 @@ static int memcg_propagate_kmem(struct mem_cgroup *memcg)
> * after this point, because it has at least one child already.
> */
> if (memcg_kmem_is_active(parent))
> - ret = __memcg_activate_kmem(memcg, RES_COUNTER_MAX);
> + ret = __memcg_activate_kmem(memcg, PAGE_COUNTER_MAX);
> mutex_unlock(&activate_kmem_mutex);
> return ret;
> }
> #else
> static int memcg_update_kmem_limit(struct mem_cgroup *memcg,
> - unsigned long long val)
> + unsigned long limit)
> {
> return -EINVAL;
> }
> @@ -4178,110 +4175,69 @@ static ssize_t mem_cgroup_write(struct kernfs_open_file *of,
> char *buf, size_t nbytes, loff_t off)
> {
> struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
> - enum res_type type;
> - int name;
> - unsigned long long val;
> + unsigned long nr_pages;
> int ret;
>
> buf = strstrip(buf);
> - type = MEMFILE_TYPE(of_cft(of)->private);
> - name = MEMFILE_ATTR(of_cft(of)->private);
> + ret = page_counter_memparse(buf, &nr_pages);
> + if (ret)
> + return ret;
>
> - switch (name) {
> + switch (MEMFILE_ATTR(of_cft(of)->private)) {
> case RES_LIMIT:
> if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */
> ret = -EINVAL;
> break;
> }
> - /* This function does all necessary parse...reuse it */
> - ret = res_counter_memparse_write_strategy(buf, &val);
> - if (ret)
> + switch (MEMFILE_TYPE(of_cft(of)->private)) {
> + case _MEM:
> + ret = mem_cgroup_resize_limit(memcg, nr_pages);
> break;
> - if (type == _MEM)
> - ret = mem_cgroup_resize_limit(memcg, val);
> - else if (type == _MEMSWAP)
> - ret = mem_cgroup_resize_memsw_limit(memcg, val);
> - else if (type == _KMEM)
> - ret = memcg_update_kmem_limit(memcg, val);
> - else
> - return -EINVAL;
> - break;
> - case RES_SOFT_LIMIT:
> - ret = res_counter_memparse_write_strategy(buf, &val);
> - if (ret)
> + case _MEMSWAP:
> + ret = mem_cgroup_resize_memsw_limit(memcg, nr_pages);
> break;
> - /*
> - * For memsw, soft limits are hard to implement in terms
> - * of semantics, for now, we support soft limits for
> - * control without swap
> - */
> - if (type == _MEM)
> - ret = res_counter_set_soft_limit(&memcg->res, val);
> - else
> - ret = -EINVAL;
> + case _KMEM:
> + ret = memcg_update_kmem_limit(memcg, nr_pages);
> + break;
> + }
> break;
> - default:
> - ret = -EINVAL; /* should be BUG() ? */
> + case RES_SOFT_LIMIT:
> + memcg->soft_limit = nr_pages;
> + ret = 0;
> break;
> }
> return ret ?: nbytes;
> }
>
> -static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg,
> - unsigned long long *mem_limit, unsigned long long *memsw_limit)
> -{
> - unsigned long long min_limit, min_memsw_limit, tmp;
> -
> - min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
> - min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
> - if (!memcg->use_hierarchy)
> - goto out;
> -
> - while (memcg->css.parent) {
> - memcg = mem_cgroup_from_css(memcg->css.parent);
> - if (!memcg->use_hierarchy)
> - break;
> - tmp = res_counter_read_u64(&memcg->res, RES_LIMIT);
> - min_limit = min(min_limit, tmp);
> - tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
> - min_memsw_limit = min(min_memsw_limit, tmp);
> - }
> -out:
> - *mem_limit = min_limit;
> - *memsw_limit = min_memsw_limit;
> -}
> -
> static ssize_t mem_cgroup_reset(struct kernfs_open_file *of, char *buf,
> size_t nbytes, loff_t off)
> {
> struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
> - int name;
> - enum res_type type;
> + struct page_counter *counter;
>
> - type = MEMFILE_TYPE(of_cft(of)->private);
> - name = MEMFILE_ATTR(of_cft(of)->private);
> + switch (MEMFILE_TYPE(of_cft(of)->private)) {
> + case _MEM:
> + counter = &memcg->memory;
> + break;
> + case _MEMSWAP:
> + counter = &memcg->memsw;
> + break;
> + case _KMEM:
> + counter = &memcg->kmem;
> + break;
> + default:
> + BUG();
> + }
>
> - switch (name) {
> + switch (MEMFILE_ATTR(of_cft(of)->private)) {
> case RES_MAX_USAGE:
> - if (type == _MEM)
> - res_counter_reset_max(&memcg->res);
> - else if (type == _MEMSWAP)
> - res_counter_reset_max(&memcg->memsw);
> - else if (type == _KMEM)
> - res_counter_reset_max(&memcg->kmem);
> - else
> - return -EINVAL;
> + page_counter_reset_watermark(counter);
> break;
> case RES_FAILCNT:
> - if (type == _MEM)
> - res_counter_reset_failcnt(&memcg->res);
> - else if (type == _MEMSWAP)
> - res_counter_reset_failcnt(&memcg->memsw);
> - else if (type == _KMEM)
> - res_counter_reset_failcnt(&memcg->kmem);
> - else
> - return -EINVAL;
> + counter->failcnt = 0;
> break;
> + default:
> + BUG();
> }
>
> return nbytes;
> @@ -4378,6 +4334,7 @@ static inline void mem_cgroup_lru_names_not_uptodate(void)
> static int memcg_stat_show(struct seq_file *m, void *v)
> {
> struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
> + unsigned long memory, memsw;
> struct mem_cgroup *mi;
> unsigned int i;
>
> @@ -4397,14 +4354,16 @@ static int memcg_stat_show(struct seq_file *m, void *v)
> mem_cgroup_nr_lru_pages(memcg, BIT(i)) * PAGE_SIZE);
>
> /* Hierarchical information */
> - {
> - unsigned long long limit, memsw_limit;
> - memcg_get_hierarchical_limit(memcg, &limit, &memsw_limit);
> - seq_printf(m, "hierarchical_memory_limit %llu\n", limit);
> - if (do_swap_account)
> - seq_printf(m, "hierarchical_memsw_limit %llu\n",
> - memsw_limit);
> + memory = memsw = PAGE_COUNTER_MAX;
> + for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) {
> + memory = min(memory, mi->memory.limit);
> + memsw = min(memsw, mi->memsw.limit);
> }
> + seq_printf(m, "hierarchical_memory_limit %llu\n",
> + (u64)memory * PAGE_SIZE);
> + if (do_swap_account)
> + seq_printf(m, "hierarchical_memsw_limit %llu\n",
> + (u64)memsw * PAGE_SIZE);
>
> for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
> long long val = 0;
> @@ -4488,7 +4447,7 @@ static int mem_cgroup_swappiness_write(struct cgroup_subsys_state *css,
> static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap)
> {
> struct mem_cgroup_threshold_ary *t;
> - u64 usage;
> + unsigned long usage;
> int i;
>
> rcu_read_lock();
> @@ -4587,10 +4546,11 @@ static int __mem_cgroup_usage_register_event(struct mem_cgroup *memcg,
> {
> struct mem_cgroup_thresholds *thresholds;
> struct mem_cgroup_threshold_ary *new;
> - u64 threshold, usage;
> + unsigned long threshold;
> + unsigned long usage;
> int i, size, ret;
>
> - ret = res_counter_memparse_write_strategy(args, &threshold);
> + ret = page_counter_memparse(args, &threshold);
> if (ret)
> return ret;
>
> @@ -4680,7 +4640,7 @@ static void __mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg,
> {
> struct mem_cgroup_thresholds *thresholds;
> struct mem_cgroup_threshold_ary *new;
> - u64 usage;
> + unsigned long usage;
> int i, j, size;
>
> mutex_lock(&memcg->thresholds_lock);
> @@ -4874,7 +4834,7 @@ static void kmem_cgroup_css_offline(struct mem_cgroup *memcg)
>
> memcg_kmem_mark_dead(memcg);
>
> - if (res_counter_read_u64(&memcg->kmem, RES_USAGE) != 0)
> + if (page_counter_read(&memcg->kmem))
> return;
>
> if (memcg_kmem_test_and_clear_dead(memcg))
> @@ -5354,9 +5314,9 @@ static void __mem_cgroup_free(struct mem_cgroup *memcg)
> */
> struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg)
> {
> - if (!memcg->res.parent)
> + if (!memcg->memory.parent)
> return NULL;
> - return mem_cgroup_from_res_counter(memcg->res.parent, res);
> + return mem_cgroup_from_counter(memcg->memory.parent, memory);
> }
> EXPORT_SYMBOL(parent_mem_cgroup);
>
> @@ -5401,9 +5361,9 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
> /* root ? */
> if (parent_css == NULL) {
> root_mem_cgroup = memcg;
> - res_counter_init(&memcg->res, NULL);
> - res_counter_init(&memcg->memsw, NULL);
> - res_counter_init(&memcg->kmem, NULL);
> + page_counter_init(&memcg->memory, NULL);
> + page_counter_init(&memcg->memsw, NULL);
> + page_counter_init(&memcg->kmem, NULL);
> }
>
> memcg->last_scanned_node = MAX_NUMNODES;
> @@ -5442,18 +5402,18 @@ mem_cgroup_css_online(struct cgroup_subsys_state *css)
> memcg->swappiness = mem_cgroup_swappiness(parent);
>
> if (parent->use_hierarchy) {
> - res_counter_init(&memcg->res, &parent->res);
> - res_counter_init(&memcg->memsw, &parent->memsw);
> - res_counter_init(&memcg->kmem, &parent->kmem);
> + page_counter_init(&memcg->memory, &parent->memory);
> + page_counter_init(&memcg->memsw, &parent->memsw);
> + page_counter_init(&memcg->kmem, &parent->kmem);
>
> /*
> * No need to take a reference to the parent because cgroup
> * core guarantees its existence.
> */
> } else {
> - res_counter_init(&memcg->res, NULL);
> - res_counter_init(&memcg->memsw, NULL);
> - res_counter_init(&memcg->kmem, NULL);
> + page_counter_init(&memcg->memory, NULL);
> + page_counter_init(&memcg->memsw, NULL);
> + page_counter_init(&memcg->kmem, NULL);
> /*
> * Deeper hierachy with use_hierarchy == false doesn't make
> * much sense so let cgroup subsystem know about this
> @@ -5535,7 +5495,7 @@ static void mem_cgroup_css_free(struct cgroup_subsys_state *css)
> /*
> * XXX: css_offline() would be where we should reparent all
> * memory to prepare the cgroup for destruction. However,
> - * memcg does not do css_tryget_online() and res_counter charging
> + * memcg does not do css_tryget_online() and page_counter charging
> * under the same RCU lock region, which means that charging
> * could race with offlining. Offlining only happens to
> * cgroups with no tasks in them but charges can show up
> @@ -5555,7 +5515,7 @@ static void mem_cgroup_css_free(struct cgroup_subsys_state *css)
> * call_rcu()
> * offline_css()
> * reparent_charges()
> - * res_counter_charge()
> + * page_counter_try_charge()
> * css_put()
> * css_free()
> * pc->mem_cgroup = dead memcg
> @@ -5590,10 +5550,10 @@ static void mem_cgroup_css_reset(struct cgroup_subsys_state *css)
> {
> struct mem_cgroup *memcg = mem_cgroup_from_css(css);
>
> - mem_cgroup_resize_limit(memcg, ULLONG_MAX);
> - mem_cgroup_resize_memsw_limit(memcg, ULLONG_MAX);
> - memcg_update_kmem_limit(memcg, ULLONG_MAX);
> - res_counter_set_soft_limit(&memcg->res, ULLONG_MAX);
> + mem_cgroup_resize_limit(memcg, PAGE_COUNTER_MAX);
> + mem_cgroup_resize_memsw_limit(memcg, PAGE_COUNTER_MAX);
> + memcg_update_kmem_limit(memcg, PAGE_COUNTER_MAX);
> + memcg->soft_limit = 0;
> }
>
> #ifdef CONFIG_MMU
> @@ -5907,19 +5867,18 @@ static void __mem_cgroup_clear_mc(void)
> if (mc.moved_swap) {
> /* uncharge swap account from the old cgroup */
> if (!mem_cgroup_is_root(mc.from))
> - res_counter_uncharge(&mc.from->memsw,
> - PAGE_SIZE * mc.moved_swap);
> -
> - for (i = 0; i < mc.moved_swap; i++)
> - css_put(&mc.from->css);
> + page_counter_uncharge(&mc.from->memsw, mc.moved_swap);
>
> /*
> - * we charged both to->res and to->memsw, so we should
> - * uncharge to->res.
> + * we charged both to->memory and to->memsw, so we
> + * should uncharge to->memory.
> */
> if (!mem_cgroup_is_root(mc.to))
> - res_counter_uncharge(&mc.to->res,
> - PAGE_SIZE * mc.moved_swap);
> + page_counter_uncharge(&mc.to->memory, mc.moved_swap);
> +
> + for (i = 0; i < mc.moved_swap; i++)
> + css_put(&mc.from->css);
> +
> /* we've already done css_get(mc.to) */
> mc.moved_swap = 0;
> }
> @@ -6285,7 +6244,7 @@ void mem_cgroup_uncharge_swap(swp_entry_t entry)
> memcg = mem_cgroup_lookup(id);
> if (memcg) {
> if (!mem_cgroup_is_root(memcg))
> - res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
> + page_counter_uncharge(&memcg->memsw, 1);
> mem_cgroup_swap_statistics(memcg, false);
> css_put(&memcg->css);
> }
> @@ -6451,11 +6410,9 @@ static void uncharge_batch(struct mem_cgroup *memcg, unsigned long pgpgout,
>
> if (!mem_cgroup_is_root(memcg)) {
> if (nr_mem)
> - res_counter_uncharge(&memcg->res,
> - nr_mem * PAGE_SIZE);
> + page_counter_uncharge(&memcg->memory, nr_mem);
> if (nr_memsw)
> - res_counter_uncharge(&memcg->memsw,
> - nr_memsw * PAGE_SIZE);
> + page_counter_uncharge(&memcg->memsw, nr_memsw);
> memcg_oom_recover(memcg);
> }
>
> diff --git a/mm/page_counter.c b/mm/page_counter.c
> new file mode 100644
> index 000000000000..fc4990c6bb5b
> --- /dev/null
> +++ b/mm/page_counter.c
> @@ -0,0 +1,203 @@
> +/*
> + * Lockless hierarchical page accounting & limiting
> + *
> + * Copyright (C) 2014 Red Hat, Inc., Johannes Weiner
> + */
> +
> +#include <linux/page_counter.h>
> +#include <linux/atomic.h>
> +#include <linux/sched.h>
> +
> +/**
> + * page_counter_cancel - take pages out of the local counter
> + * @counter: counter
> + * @nr_pages: number of pages to cancel
> + *
> + * Returns whether there are remaining pages in the counter.
> + */
> +int page_counter_cancel(struct page_counter *counter, unsigned long nr_pages)
> +{
> + long new;
> +
> + new = atomic_long_sub_return(nr_pages, &counter->count);
> +
> + /* More uncharges than charges? */
> + WARN_ON_ONCE(new < 0);
> +
> + return new > 0;
> +}
> +
> +/**
> + * page_counter_charge - hierarchically charge pages
> + * @counter: counter
> + * @nr_pages: number of pages to charge
> + *
> + * NOTE: This does not consider any configured counter limits.
> + */
> +void page_counter_charge(struct page_counter *counter, unsigned long nr_pages)
> +{
> + struct page_counter *c;
> +
> + for (c = counter; c; c = c->parent) {
> + long new;
> +
> + new = atomic_long_add_return(nr_pages, &c->count);
> + /*
> + * This is indeed racy, but we can live with some
> + * inaccuracy in the watermark.
> + */
> + if (new > c->watermark)
> + c->watermark = new;
> + }
> +}
> +
> +/**
> + * page_counter_try_charge - try to hierarchically charge pages
> + * @counter: counter
> + * @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.
> + */
> +int page_counter_try_charge(struct page_counter *counter,
> + unsigned long nr_pages,
> + struct page_counter **fail)
> +{
> + struct page_counter *c;
> +
> + for (c = counter; c; c = c->parent) {
> + long new;
> + /*
> + * Charge speculatively to avoid an expensive CAS. If
> + * a bigger charge fails, it might falsely lock out a
> + * racing smaller charge and send it into reclaim
> + * early, but the error is limited to the difference
> + * between the two sizes, which is less than 2M/4M in
> + * case of a THP locking out a regular page charge.
> + *
> + * The atomic_long_add_return() implies a full memory
> + * barrier between incrementing the count and reading
> + * the limit. When racing with page_counter_limit(),
> + * we either see the new limit or the setter sees the
> + * counter has changed and retries.
> + */
> + new = atomic_long_add_return(nr_pages, &c->count);
> + if (new > c->limit) {
> + atomic_long_sub(nr_pages, &c->count);
> + /*
> + * This is racy, but we can live with some
> + * inaccuracy in the failcnt.
> + */
> + c->failcnt++;
> + *fail = c;
> + goto failed;
> + }
> + /*
> + * Just like with failcnt, we can live with some
> + * inaccuracy in the watermark.
> + */
> + if (new > c->watermark)
> + c->watermark = new;
> + }
> + return 0;
> +
> +failed:
> + for (c = counter; c != *fail; c = c->parent)
> + page_counter_cancel(c, nr_pages);
> +
> + return -ENOMEM;
> +}
> +
> +/**
> + * page_counter_uncharge - hierarchically uncharge pages
> + * @counter: counter
> + * @nr_pages: number of pages to uncharge
> + *
> + * Returns whether there are remaining charges in @counter.
> + */
> +int page_counter_uncharge(struct page_counter *counter, unsigned long nr_pages)
> +{
> + struct page_counter *c;
> + int ret = 1;
> +
> + for (c = counter; c; c = c->parent) {
> + int remainder;
> +
> + remainder = page_counter_cancel(c, nr_pages);
> + if (c == counter && !remainder)
> + ret = 0;
> + }
> +
> + return ret;
> +}
> +
> +/**
> + * page_counter_limit - limit the number of pages allowed
> + * @counter: counter
> + * @limit: limit to set
> + *
> + * Returns 0 on success, -EBUSY if the current number of pages on the
> + * counter already exceeds the specified limit.
> + *
> + * The caller must serialize invocations on the same counter.
> + */
> +int page_counter_limit(struct page_counter *counter, unsigned long limit)
> +{
> + for (;;) {
> + unsigned long old;
> + long count;
> +
> + /*
> + * Update the limit while making sure that it's not
> + * below the concurrently-changing counter value.
> + *
> + * The xchg implies two full memory barriers before
> + * and after, so the read-swap-read is ordered and
> + * ensures coherency with page_counter_try_charge():
> + * that function modifies the count before checking
> + * the limit, so if it sees the old limit, we see the
> + * modified counter and retry.
> + */
> + count = atomic_long_read(&counter->count);
> +
> + if (count > limit)
> + return -EBUSY;
> +
> + old = xchg(&counter->limit, limit);
> +
> + if (atomic_long_read(&counter->count) <= count)
> + return 0;
> +
> + counter->limit = old;
> + cond_resched();
> + }
> +}
> +
> +/**
> + * page_counter_memparse - memparse() for page counter limits
> + * @buf: string to parse
> + * @nr_pages: returns the result in number of pages
> + *
> + * Returns -EINVAL, or 0 and @nr_pages on success. @nr_pages will be
> + * limited to %PAGE_COUNTER_MAX.
> + */
> +int page_counter_memparse(const char *buf, unsigned long *nr_pages)
> +{
> + char unlimited[] = "-1";
> + char *end;
> + u64 bytes;
> +
> + if (!strncmp(buf, unlimited, sizeof(unlimited))) {
> + *nr_pages = PAGE_COUNTER_MAX;
> + return 0;
> + }
> +
> + bytes = memparse(buf, &end);
> + if (*end != '\0')
> + return -EINVAL;
> +
> + *nr_pages = min(bytes / PAGE_SIZE, (u64)PAGE_COUNTER_MAX);
> +
> + return 0;
> +}
> diff --git a/net/ipv4/tcp_memcontrol.c b/net/ipv4/tcp_memcontrol.c
> index 1d191357bf88..272327134a1b 100644
> --- a/net/ipv4/tcp_memcontrol.c
> +++ b/net/ipv4/tcp_memcontrol.c
> @@ -9,13 +9,13 @@
> int tcp_init_cgroup(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
> {
> /*
> - * The root cgroup does not use res_counters, but rather,
> + * The root cgroup does not use page_counters, but rather,
> * rely on the data already collected by the network
> * subsystem
> */
> - struct res_counter *res_parent = NULL;
> - struct cg_proto *cg_proto, *parent_cg;
> struct mem_cgroup *parent = parent_mem_cgroup(memcg);
> + struct page_counter *counter_parent = NULL;
> + struct cg_proto *cg_proto, *parent_cg;
>
> cg_proto = tcp_prot.proto_cgroup(memcg);
> if (!cg_proto)
> @@ -29,9 +29,9 @@ int tcp_init_cgroup(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
>
> parent_cg = tcp_prot.proto_cgroup(parent);
> if (parent_cg)
> - res_parent = &parent_cg->memory_allocated;
> + counter_parent = &parent_cg->memory_allocated;
>
> - res_counter_init(&cg_proto->memory_allocated, res_parent);
> + page_counter_init(&cg_proto->memory_allocated, counter_parent);
> percpu_counter_init(&cg_proto->sockets_allocated, 0, GFP_KERNEL);
>
> return 0;
> @@ -50,7 +50,7 @@ void tcp_destroy_cgroup(struct mem_cgroup *memcg)
> }
> EXPORT_SYMBOL(tcp_destroy_cgroup);
>
> -static int tcp_update_limit(struct mem_cgroup *memcg, u64 val)
> +static int tcp_update_limit(struct mem_cgroup *memcg, unsigned long nr_pages)
> {
> struct cg_proto *cg_proto;
> int i;
> @@ -60,20 +60,17 @@ static int tcp_update_limit(struct mem_cgroup *memcg, u64 val)
> if (!cg_proto)
> return -EINVAL;
>
> - if (val > RES_COUNTER_MAX)
> - val = RES_COUNTER_MAX;
> -
> - ret = res_counter_set_limit(&cg_proto->memory_allocated, val);
> + ret = page_counter_limit(&cg_proto->memory_allocated, nr_pages);
> if (ret)
> return ret;
>
> for (i = 0; i < 3; i++)
> - cg_proto->sysctl_mem[i] = min_t(long, val >> PAGE_SHIFT,
> + cg_proto->sysctl_mem[i] = min_t(long, nr_pages,
> sysctl_tcp_mem[i]);
>
> - if (val == RES_COUNTER_MAX)
> + if (nr_pages == PAGE_COUNTER_MAX)
> clear_bit(MEMCG_SOCK_ACTIVE, &cg_proto->flags);
> - else if (val != RES_COUNTER_MAX) {
> + else {
> /*
> * The active bit needs to be written after the static_key
> * update. This is what guarantees that the socket activation
> @@ -102,11 +99,20 @@ static int tcp_update_limit(struct mem_cgroup *memcg, u64 val)
> return 0;
> }
>
> +enum {
> + RES_USAGE,
> + RES_LIMIT,
> + RES_MAX_USAGE,
> + RES_FAILCNT,
> +};
> +
> +static DEFINE_MUTEX(tcp_limit_mutex);
> +
> static ssize_t tcp_cgroup_write(struct kernfs_open_file *of,
> char *buf, size_t nbytes, loff_t off)
> {
> struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
> - unsigned long long val;
> + unsigned long nr_pages;
> int ret = 0;
>
> buf = strstrip(buf);
> @@ -114,10 +120,12 @@ static ssize_t tcp_cgroup_write(struct kernfs_open_file *of,
> switch (of_cft(of)->private) {
> case RES_LIMIT:
> /* see memcontrol.c */
> - ret = res_counter_memparse_write_strategy(buf, &val);
> + ret = page_counter_memparse(buf, &nr_pages);
> if (ret)
> break;
> - ret = tcp_update_limit(memcg, val);
> + mutex_lock(&tcp_limit_mutex);
> + ret = tcp_update_limit(memcg, nr_pages);
> + mutex_unlock(&tcp_limit_mutex);
> break;
> default:
> ret = -EINVAL;
> @@ -126,43 +134,36 @@ static ssize_t tcp_cgroup_write(struct kernfs_open_file *of,
> return ret ?: nbytes;
> }
>
> -static u64 tcp_read_stat(struct mem_cgroup *memcg, int type, u64 default_val)
> -{
> - struct cg_proto *cg_proto;
> -
> - cg_proto = tcp_prot.proto_cgroup(memcg);
> - if (!cg_proto)
> - return default_val;
> -
> - return res_counter_read_u64(&cg_proto->memory_allocated, type);
> -}
> -
> -static u64 tcp_read_usage(struct mem_cgroup *memcg)
> -{
> - struct cg_proto *cg_proto;
> -
> - cg_proto = tcp_prot.proto_cgroup(memcg);
> - if (!cg_proto)
> - return atomic_long_read(&tcp_memory_allocated) << PAGE_SHIFT;
> -
> - return res_counter_read_u64(&cg_proto->memory_allocated, RES_USAGE);
> -}
> -
> static u64 tcp_cgroup_read(struct cgroup_subsys_state *css, struct cftype *cft)
> {
> struct mem_cgroup *memcg = mem_cgroup_from_css(css);
> + struct cg_proto *cg_proto = tcp_prot.proto_cgroup(memcg);
> u64 val;
>
> switch (cft->private) {
> case RES_LIMIT:
> - val = tcp_read_stat(memcg, RES_LIMIT, RES_COUNTER_MAX);
> + if (!cg_proto)
> + return PAGE_COUNTER_MAX;
> + val = cg_proto->memory_allocated.limit;
> + val *= PAGE_SIZE;
> break;
> case RES_USAGE:
> - val = tcp_read_usage(memcg);
> + if (!cg_proto)
> + val = atomic_long_read(&tcp_memory_allocated);
> + else
> + val = page_counter_read(&cg_proto->memory_allocated);
> + val *= PAGE_SIZE;
> break;
> case RES_FAILCNT:
> + if (!cg_proto)
> + return 0;
> + val = cg_proto->memory_allocated.failcnt;
> + break;
> case RES_MAX_USAGE:
> - val = tcp_read_stat(memcg, cft->private, 0);
> + if (!cg_proto)
> + return 0;
> + val = cg_proto->memory_allocated.watermark;
> + val *= PAGE_SIZE;
> break;
> default:
> BUG();
> @@ -183,10 +184,10 @@ static ssize_t tcp_cgroup_reset(struct kernfs_open_file *of,
>
> switch (of_cft(of)->private) {
> case RES_MAX_USAGE:
> - res_counter_reset_max(&cg_proto->memory_allocated);
> + page_counter_reset_watermark(&cg_proto->memory_allocated);
> break;
> case RES_FAILCNT:
> - res_counter_reset_failcnt(&cg_proto->memory_allocated);
> + cg_proto->memory_allocated.failcnt = 0;
> break;
> }
>
> --
> 2.1.2
>

--
Michal Hocko
SUSE Labs