This patch is an experimental patch.
Considering 32bit archs, I think this should be CONFIG option...
==
Now, struct page_cgroup is 8byte object and allocated per a page.
This patch adds a config option to allocate page_cgroup in struct page.
By this
Pros.
- lookup_page_cgroup() is almost 0 cost.
- implementation seems very natural...
Cons.
- size of 'struct page' will be increased (to 64bytes in typical case)
- cgroup_disable=memory will not allow user to avoid 8bytes of overhead.
Tested 'kernel make' on tmpfs.
Config=n
Performance counter stats for 'make -j 8':
1,180,857,100,495 instructions # 0.00 insns per cycle
923,084,678 cache-misses
71.346377273 seconds time elapsed
Config=y
Performance counter stats for 'make -j 8':
1,178,404,304,530 instructions # 0.00 insns per cycle
911,098,615 cache-misses
71.607477840 seconds time elapsed
seems instructions and cache-misses decreased to some extent.
But no visible change in total execution time...
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
---
include/linux/mm_types.h | 4 +++-
include/linux/page_cgroup.h | 33 ++++++++++++++++++++++++++++++++-
init/Kconfig | 14 ++++++++++++++
mm/memcontrol.c | 3 ++-
mm/page_alloc.c | 1 +
mm/page_cgroup.c | 3 ++-
6 files changed, 54 insertions(+), 4 deletions(-)
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 76bbdaf..2beda78 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -141,7 +141,9 @@ struct page {
#ifdef CONFIG_WANT_PAGE_DEBUG_FLAGS
unsigned long debug_flags; /* Use atomic bitops on this */
#endif
-
+#ifdef CONFIG_INTEGRATED_PAGE_CGROUP
+ unsigned long page_cgroup; /* see page_cgroup.h */
+#endif
#ifdef CONFIG_KMEMCHECK
/*
* kmemcheck wants to track the status of each byte in a page; this
diff --git a/include/linux/page_cgroup.h b/include/linux/page_cgroup.h
index 7e3a3c7..0e02632 100644
--- a/include/linux/page_cgroup.h
+++ b/include/linux/page_cgroup.h
@@ -35,8 +35,9 @@ struct page_cgroup {
unsigned long flags;
};
-void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat);
+#ifndef CONFIG_INTEGRATED_PAGE_CGROUP
+void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat);
#ifdef CONFIG_SPARSEMEM
static inline void __init page_cgroup_init_flatmem(void)
{
@@ -51,6 +52,36 @@ static inline void __init page_cgroup_init(void)
struct page_cgroup *lookup_page_cgroup(struct page *page);
struct page *lookup_cgroup_page(struct page_cgroup *pc);
+static inline void memmap_init_cgroup(struct page *page)
+{
+}
+#else
+static inline struct page_cgroup *lookup_page_cgroup(struct page *page)
+{
+ return (struct page_cgroup*)&page->page_cgroup;
+}
+
+static inline struct page *lookup_cgroup_page(struct page_cgroup *pc)
+{
+ return container_of((unsigned long*)pc, struct page, page_cgroup);
+}
+
+static inline void memmap_init_cgroup(struct page *page)
+{
+ page->page_cgroup = 0;
+}
+
+static inline void __init page_cgroup_init_flatmem(void)
+{
+}
+static inline void __init page_cgroup_init(void)
+{
+}
+
+static inline void pgdat_page_cgroup_init(struct pglist_data *pgdat)
+{
+}
+#endif
#define TESTPCGFLAG(uname, lname) \
static inline int PageCgroup##uname(struct page_cgroup *pc) \
diff --git a/init/Kconfig b/init/Kconfig
index e0bfe92..99514c2 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -694,6 +694,20 @@ config CGROUP_MEM_RES_CTLR_SWAP_ENABLED
For those who want to have the feature enabled by default should
select this option (if, for some reason, they need to disable it
then swapaccount=0 does the trick).
+
+config INTEGRATED_PAGE_CGROUP
+ bool "record memory cgroup information into struct page"
+ depends on CGROUP_MEM_RES_CTLR
+ default n
+ help
+ Memory Resource Controller consumes 4/(8 if 64bit)bytes per page.
+ It's independent of 'struct page'. If you say Y here, memory cgroup
+ information is recorded into struct page and increase size of it
+ 4/8 bytes. With this, cpu overheads in runtime will be reduced
+ but you cannot avoid above overheads of 4/8 bytes per page by boot
+ option. If unsure, say N.
+
+
config CGROUP_MEM_RES_CTLR_KMEM
bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)"
depends on CGROUP_MEM_RES_CTLR && EXPERIMENTAL
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 767bef3..0c5b15c 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2557,7 +2557,8 @@ void mem_cgroup_split_huge_fixup(struct page *head)
if (!PageCgroupUsed(head_pc))
return;
for (i = 1; i < HPAGE_PMD_NR; i++) {
- pc = head_pc + i;
+ /* page struct is contiguous in hugepage. */
+ pc = lookup_page_cgroup(head + i);
pc_set_mem_cgroup_and_flags(pc, memcg, BIT(PCG_USED));
}
}
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 0b37873..9be94df 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3682,6 +3682,7 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
if (!is_highmem_idx(zone))
set_page_address(page, __va(pfn << PAGE_SHIFT));
#endif
+ memmap_init_cgroup(page);
}
}
diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c
index 1ccbd71..036c8ea 100644
--- a/mm/page_cgroup.c
+++ b/mm/page_cgroup.c
@@ -11,6 +11,7 @@
#include <linux/swapops.h>
#include <linux/kmemleak.h>
+#ifndef CONFIG_INTEGRATED_PAGE_CGROUP
static unsigned long total_usage;
#if !defined(CONFIG_SPARSEMEM)
@@ -315,7 +316,7 @@ void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
}
#endif
-
+#endif
#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
--
1.7.4.1
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