diff mbox series

[mm,v4,3/4] mm: move cgroup high memory limit setting into struct page_counter

Message ID 20200519171938.3569605-4-kuba@kernel.org (mailing list archive)
State New, archived
Headers show
Series memcg: Slow down swap allocation as the available space gets depleted | expand

Commit Message

Jakub Kicinski May 19, 2020, 5:19 p.m. UTC 
High memory limit is currently recorded directly in
struct mem_cgroup. We are about to add a high limit
for swap, move the field to struct page_counter and
add some helpers.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
--
v4: new patch
---
 include/linux/memcontrol.h   |  3 ---
 include/linux/page_counter.h |  8 ++++++++
 mm/memcontrol.c              | 17 +++++++++--------
 mm/page_counter.c            |  5 +++++
 4 files changed, 22 insertions(+), 11 deletions(-)

Comments

Shakeel Butt May 19, 2020, 10:15 p.m. UTC | #1 
On Tue, May 19, 2020 at 10:19 AM Jakub Kicinski <kuba@kernel.org> wrote:
>
> High memory limit is currently recorded directly in
> struct mem_cgroup. We are about to add a high limit
> for swap, move the field to struct page_counter and
> add some helpers.
>
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Reviewed-by: Shakeel Butt <shakeelb@google.com>

> --- a/include/linux/page_counter.h
> +++ b/include/linux/page_counter.h
...
[snip]
...
>
> +static inline bool page_counter_is_above_high(struct page_counter *counter)
> +{
> +       return page_counter_read(counter) > READ_ONCE(counter->high);
> +}
> +
...
[snip]
...
> --- a/mm/page_counter.c
> +++ b/mm/page_counter.c
> @@ -198,6 +198,11 @@ int page_counter_set_max(struct page_counter *counter, unsigned long nr_pages)
>         }
>  }
>
> +void page_counter_set_high(struct page_counter *counter, unsigned long nr_pages)
> +{
> +       WRITE_ONCE(counter->high, nr_pages);
> +}
> +

Any reason not to make this static inline like
page_counter_is_above_high() and in page_counter.h?
Jakub Kicinski May 19, 2020, 11:14 p.m. UTC | #2 
On Tue, 19 May 2020 15:15:41 -0700 Shakeel Butt wrote:
> > --- a/mm/page_counter.c
> > +++ b/mm/page_counter.c
> > @@ -198,6 +198,11 @@ int page_counter_set_max(struct page_counter *counter, unsigned long nr_pages)
> >         }
> >  }
> >
> > +void page_counter_set_high(struct page_counter *counter, unsigned long nr_pages)
> > +{
> > +       WRITE_ONCE(counter->high, nr_pages);
> > +}
> > +  
> 
> Any reason not to make this static inline like
> page_counter_is_above_high() and in page_counter.h?

My reason was consistency with other page_counter_set_xyz() helpers,
but obviously happy to change if needed...
Shakeel Butt May 20, 2020, 12:21 a.m. UTC | #3 
On Tue, May 19, 2020 at 4:14 PM Jakub Kicinski <kuba@kernel.org> wrote:
>
> On Tue, 19 May 2020 15:15:41 -0700 Shakeel Butt wrote:
> > > --- a/mm/page_counter.c
> > > +++ b/mm/page_counter.c
> > > @@ -198,6 +198,11 @@ int page_counter_set_max(struct page_counter *counter, unsigned long nr_pages)
> > >         }
> > >  }
> > >
> > > +void page_counter_set_high(struct page_counter *counter, unsigned long nr_pages)
> > > +{
> > > +       WRITE_ONCE(counter->high, nr_pages);
> > > +}
> > > +
> >
> > Any reason not to make this static inline like
> > page_counter_is_above_high() and in page_counter.h?
>
> My reason was consistency with other page_counter_set_xyz() helpers,
> but obviously happy to change if needed...

I think it should be in the header and inlined.
diff mbox series

Patch

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index e0bcef180672..d726867d8af9 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -206,9 +206,6 @@  struct mem_cgroup {
 	struct page_counter kmem;
 	struct page_counter tcpmem;
 
-	/* Upper bound of normal memory consumption range */
-	unsigned long high;
-
 	/* Range enforcement for interrupt charges */
 	struct work_struct high_work;
 
diff --git a/include/linux/page_counter.h b/include/linux/page_counter.h
index bab7e57f659b..c7606a204530 100644
--- a/include/linux/page_counter.h
+++ b/include/linux/page_counter.h
@@ -10,6 +10,7 @@  struct page_counter {
 	atomic_long_t usage;
 	unsigned long min;
 	unsigned long low;
+	unsigned long high;
 	unsigned long max;
 	struct page_counter *parent;
 
@@ -55,6 +56,8 @@  bool page_counter_try_charge(struct page_counter *counter,
 void page_counter_uncharge(struct page_counter *counter, unsigned long nr_pages);
 void page_counter_set_min(struct page_counter *counter, unsigned long nr_pages);
 void page_counter_set_low(struct page_counter *counter, unsigned long nr_pages);
+void page_counter_set_high(struct page_counter *counter,
+			   unsigned long nr_pages);
 int page_counter_set_max(struct page_counter *counter, unsigned long nr_pages);
 int page_counter_memparse(const char *buf, const char *max,
 			  unsigned long *nr_pages);
@@ -64,4 +67,9 @@  static inline void page_counter_reset_watermark(struct page_counter *counter)
 	counter->watermark = page_counter_read(counter);
 }
 
+static inline bool page_counter_is_above_high(struct page_counter *counter)
+{
+	return page_counter_read(counter) > READ_ONCE(counter->high);
+}
+
 #endif /* _LINUX_PAGE_COUNTER_H */
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index dd8605a9137a..d4b7bc80aa38 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2233,7 +2233,7 @@  static void reclaim_high(struct mem_cgroup *memcg,
 			 gfp_t gfp_mask)
 {
 	do {
-		if (page_counter_read(&memcg->memory) <= READ_ONCE(memcg->high))
+		if (!page_counter_is_above_high(&memcg->memory))
 			continue;
 		memcg_memory_event(memcg, MEMCG_HIGH);
 		try_to_free_mem_cgroup_pages(memcg, nr_pages, gfp_mask, true);
@@ -2326,7 +2326,7 @@  static u64 mem_find_max_overage(struct mem_cgroup *memcg)
 
 	do {
 		overage = calculate_overage(page_counter_read(&memcg->memory),
-					    READ_ONCE(memcg->high));
+					    READ_ONCE(memcg->memory.high));
 		max_overage = max(overage, max_overage);
 	} while ((memcg = parent_mem_cgroup(memcg)) &&
 		 !mem_cgroup_is_root(memcg));
@@ -2585,7 +2585,7 @@  static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
 	 * reclaim, the cost of mismatch is negligible.
 	 */
 	do {
-		if (page_counter_read(&memcg->memory) > READ_ONCE(memcg->high)) {
+		if (page_counter_is_above_high(&memcg->memory)) {
 			/* Don't bother a random interrupted task */
 			if (in_interrupt()) {
 				schedule_work(&memcg->high_work);
@@ -4286,7 +4286,7 @@  void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages,
 
 	while ((parent = parent_mem_cgroup(memcg))) {
 		unsigned long ceiling = min(READ_ONCE(memcg->memory.max),
-					    READ_ONCE(memcg->high));
+					    READ_ONCE(memcg->memory.high));
 		unsigned long used = page_counter_read(&memcg->memory);
 
 		*pheadroom = min(*pheadroom, ceiling - min(ceiling, used));
@@ -5011,7 +5011,7 @@  mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
 	if (IS_ERR(memcg))
 		return ERR_CAST(memcg);
 
-	WRITE_ONCE(memcg->high, PAGE_COUNTER_MAX);
+	page_counter_set_high(&memcg->memory, PAGE_COUNTER_MAX);
 	memcg->soft_limit = PAGE_COUNTER_MAX;
 	if (parent) {
 		memcg->swappiness = mem_cgroup_swappiness(parent);
@@ -5164,7 +5164,7 @@  static void mem_cgroup_css_reset(struct cgroup_subsys_state *css)
 	page_counter_set_max(&memcg->tcpmem, PAGE_COUNTER_MAX);
 	page_counter_set_min(&memcg->memory, 0);
 	page_counter_set_low(&memcg->memory, 0);
-	WRITE_ONCE(memcg->high, PAGE_COUNTER_MAX);
+	page_counter_set_high(&memcg->memory, PAGE_COUNTER_MAX);
 	memcg->soft_limit = PAGE_COUNTER_MAX;
 	memcg_wb_domain_size_changed(memcg);
 }
@@ -5984,7 +5984,8 @@  static ssize_t memory_low_write(struct kernfs_open_file *of,
 
 static int memory_high_show(struct seq_file *m, void *v)
 {
-	return seq_puts_memcg_tunable(m, READ_ONCE(mem_cgroup_from_seq(m)->high));
+	return seq_puts_memcg_tunable(m,
+		READ_ONCE(mem_cgroup_from_seq(m)->memory.high));
 }
 
 static ssize_t memory_high_write(struct kernfs_open_file *of,
@@ -6001,7 +6002,7 @@  static ssize_t memory_high_write(struct kernfs_open_file *of,
 	if (err)
 		return err;
 
-	WRITE_ONCE(memcg->high, high);
+	page_counter_set_high(&memcg->memory, high);
 
 	for (;;) {
 		unsigned long nr_pages = page_counter_read(&memcg->memory);
diff --git a/mm/page_counter.c b/mm/page_counter.c
index e3a205275a0b..a6b2d3cfa29d 100644
--- a/mm/page_counter.c
+++ b/mm/page_counter.c
@@ -198,6 +198,11 @@  int page_counter_set_max(struct page_counter *counter, unsigned long nr_pages)
 	}
 }
 
+void page_counter_set_high(struct page_counter *counter, unsigned long nr_pages)
+{
+	WRITE_ONCE(counter->high, nr_pages);
+}
+
 /**
  * page_counter_set_min - set the amount of protected memory
  * @counter: counter