[RFC] [PATCH] Memory controller remove control_type feature
From: Balbir Singh
Date: Thu Dec 20 2007 - 13:54:35 EST
Based on the discussion at http://lkml.org/lkml/2007/12/20/383, it was
felt that control_type might not be a good thing to implement right away.
We can add this flexibility at a later point when required.
Signed-off-by: Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx>
---
include/linux/memcontrol.h | 6 --
mm/memcontrol.c | 91 ++++++++-------------------------------------
2 files changed, 18 insertions(+), 79 deletions(-)
diff -puN mm/memcontrol.c~memory-controller-no-more-control-type mm/memcontrol.c
--- linux-2.6.24-rc5/mm/memcontrol.c~memory-controller-no-more-control-type 2007-12-20 22:37:17.000000000 +0530
+++ linux-2.6.24-rc5-balbir/mm/memcontrol.c 2007-12-20 23:50:47.000000000 +0530
@@ -131,7 +131,6 @@ struct mem_cgroup {
*/
struct mem_cgroup_lru_info info;
- unsigned long control_type; /* control RSS or RSS+Pagecache */
int prev_priority; /* for recording reclaim priority */
/*
* statistics.
@@ -718,24 +717,17 @@ int mem_cgroup_cache_charge(struct page
gfp_t gfp_mask)
{
int ret = 0;
- struct mem_cgroup *mem;
if (!mm)
mm = &init_mm;
- rcu_read_lock();
- mem = rcu_dereference(mm->mem_cgroup);
- css_get(&mem->css);
- rcu_read_unlock();
- if (mem->control_type == MEM_CGROUP_TYPE_ALL)
- ret = mem_cgroup_charge_common(page, mm, gfp_mask,
+ ret = mem_cgroup_charge_common(page, mm, gfp_mask,
MEM_CGROUP_CHARGE_TYPE_CACHE);
- css_put(&mem->css);
return ret;
}
/*
* Uncharging is always a welcome operation, we never complain, simply
- * uncharge.
+ * uncharge. This routine should be called with lock_page_cgroup held
*/
void mem_cgroup_uncharge(struct page_cgroup *pc)
{
@@ -745,8 +737,7 @@ void mem_cgroup_uncharge(struct page_cgr
unsigned long flags;
/*
- * This can handle cases when a page is not charged at all and we
- * are switching between handling the control_type.
+ * Check if our page_cgroup is valid
*/
if (!pc)
return;
@@ -758,6 +749,7 @@ void mem_cgroup_uncharge(struct page_cgr
* get page->cgroup and clear it under lock.
* force_empty can drop page->cgroup without checking refcnt.
*/
+ unlock_page_cgroup(page);
if (clear_page_cgroup(page, pc) == pc) {
mem = pc->mem_cgroup;
css_put(&mem->css);
@@ -767,9 +759,17 @@ void mem_cgroup_uncharge(struct page_cgr
spin_unlock_irqrestore(&mz->lru_lock, flags);
kfree(pc);
}
+ lock_page_cgroup(page);
}
}
+void mem_cgroup_uncharge_page(struct page *page)
+{
+ lock_page_cgroup(page);
+ mem_cgroup_uncharge(page_get_page_cgroup(page));
+ unlock_page_cgroup(page);
+}
+
/*
* Returns non-zero if a page (under migration) has valid page_cgroup member.
* Refcnt of page_cgroup is incremented.
@@ -789,8 +789,12 @@ int mem_cgroup_prepare_migration(struct
void mem_cgroup_end_migration(struct page *page)
{
- struct page_cgroup *pc = page_get_page_cgroup(page);
+ struct page_cgroup *pc;
+
+ lock_page_cgroup(page);
+ pc = page_get_page_cgroup(page);
mem_cgroup_uncharge(pc);
+ unlock_page_cgroup(page);
}
/*
* We know both *page* and *newpage* are now not-on-LRU and Pg_locked.
@@ -945,61 +949,6 @@ static ssize_t mem_cgroup_write(struct c
mem_cgroup_write_strategy);
}
-static ssize_t mem_control_type_write(struct cgroup *cont,
- struct cftype *cft, struct file *file,
- const char __user *userbuf,
- size_t nbytes, loff_t *pos)
-{
- int ret;
- char *buf, *end;
- unsigned long tmp;
- struct mem_cgroup *mem;
-
- mem = mem_cgroup_from_cont(cont);
- buf = kmalloc(nbytes + 1, GFP_KERNEL);
- ret = -ENOMEM;
- if (buf == NULL)
- goto out;
-
- buf[nbytes] = 0;
- ret = -EFAULT;
- if (copy_from_user(buf, userbuf, nbytes))
- goto out_free;
-
- ret = -EINVAL;
- tmp = simple_strtoul(buf, &end, 10);
- if (*end != '\0')
- goto out_free;
-
- if (tmp <= MEM_CGROUP_TYPE_UNSPEC || tmp >= MEM_CGROUP_TYPE_MAX)
- goto out_free;
-
- mem->control_type = tmp;
- ret = nbytes;
-out_free:
- kfree(buf);
-out:
- return ret;
-}
-
-static ssize_t mem_control_type_read(struct cgroup *cont,
- struct cftype *cft,
- struct file *file, char __user *userbuf,
- size_t nbytes, loff_t *ppos)
-{
- unsigned long val;
- char buf[64], *s;
- struct mem_cgroup *mem;
-
- mem = mem_cgroup_from_cont(cont);
- s = buf;
- val = mem->control_type;
- s += sprintf(s, "%lu\n", val);
- return simple_read_from_buffer((void __user *)userbuf, nbytes,
- ppos, buf, s - buf);
-}
-
-
static ssize_t mem_force_empty_write(struct cgroup *cont,
struct cftype *cft, struct file *file,
const char __user *userbuf,
@@ -1098,11 +1047,6 @@ static struct cftype mem_cgroup_files[]
.read = mem_cgroup_read,
},
{
- .name = "control_type",
- .write = mem_control_type_write,
- .read = mem_control_type_read,
- },
- {
.name = "force_empty",
.write = mem_force_empty_write,
.read = mem_force_empty_read,
@@ -1170,7 +1114,6 @@ mem_cgroup_create(struct cgroup_subsys *
res_counter_init(&mem->res);
- mem->control_type = MEM_CGROUP_TYPE_ALL;
memset(&mem->info, 0, sizeof(mem->info));
for_each_node_state(node, N_POSSIBLE)
diff -puN include/linux/memcontrol.h~memory-controller-no-more-control-type include/linux/memcontrol.h
--- linux-2.6.24-rc5/include/linux/memcontrol.h~memory-controller-no-more-control-type 2007-12-20 22:37:17.000000000 +0530
+++ linux-2.6.24-rc5-balbir/include/linux/memcontrol.h 2007-12-20 22:40:00.000000000 +0530
@@ -35,6 +35,7 @@ extern struct page_cgroup *page_get_page
extern int mem_cgroup_charge(struct page *page, struct mm_struct *mm,
gfp_t gfp_mask);
extern void mem_cgroup_uncharge(struct page_cgroup *pc);
+extern void mem_cgroup_uncharge_page(struct page *page);
extern void mem_cgroup_move_lists(struct page_cgroup *pc, bool active);
extern unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
struct list_head *dst,
@@ -52,11 +53,6 @@ static inline struct mem_cgroup *mm_cgro
return rcu_dereference(mm->mem_cgroup);
}
-static inline void mem_cgroup_uncharge_page(struct page *page)
-{
- mem_cgroup_uncharge(page_get_page_cgroup(page));
-}
-
extern int mem_cgroup_prepare_migration(struct page *page);
extern void mem_cgroup_end_migration(struct page *page);
extern void mem_cgroup_page_migration(struct page *page, struct page *newpage);
_
--
Warm Regards,
Balbir Singh
Linux Technology Center
IBM, ISTL
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