[PATCH 6/10] BC: kernel memory (core)

Kirill Korotaev
2006-10-05T15:51:23Z

Introduce BC_KMEMSIZE resource which accounts kernel
objects allocated by task's request.

Reference to BC is kept on struct page or slab object.
For slabs each struct slab contains a set of pointers
corresponding objects are charged to.

Allocation charge rules:
1. Pages - if allocation is performed with __GFP_BC flag - page
is charged to current's exec_bc.
2. Slabs - kmem_cache may be created with SLAB_BC flag - in this
case each allocation is charged. Caches used by kmalloc are
created with SLAB_BC | SLAB_BC_NOCHARGE flags. In this case
only __GFP_BC allocations are charged.

Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: Kirill Korotaev <dev@openvz.org>

---

include/bc/kmem.h | 48 ++++++++++++++++++++
include/linux/gfp.h | 8 ++-
include/linux/mm.h | 1
include/linux/mm_types.h | 3 +
include/linux/slab.h | 4 +
include/linux/vmalloc.h | 1
kernel/bc/kmem.c | 112 +++++++++++++++++++++++++++++++++++++++++++++++
mm/mempool.c | 2
mm/page_alloc.c | 11 ++++
mm/slab.c | 112 +++++++++++++++++++++++++++++++++++++++--------
mm/vmalloc.c | 6 ++
11 files changed, 287 insertions(+), 21 deletions(-)

--- /dev/null 2006-07-18 14:52:43.075228448 +0400
+++ ./include/bc/kmem.h 2006-10-05 12:13:58.000000000 +0400
@@ -0,0 +1,48 @@
+/*
+ * include/bc/kmem.h
+ *
+ * Copyright (C) 2006 OpenVZ SWsoft Inc
+ *
+ */
+
+#ifndef __BC_KMEM_H_
+#define __BC_KMEM_H_
+
+/*
+ * BC_KMEMSIZE accounting
+ */
+
+#include <linux/slab.h>
+#include <linux/gfp.h>
+
+struct page;
+struct beancounter;
+
+#ifdef CONFIG_BEANCOUNTERS
+int __must_check bc_page_charge(struct page *page, int order, gfp_t flags);
+void bc_page_uncharge(struct page *page, int order);
+
+int __must_check bc_slab_charge(kmem_cache_t *cachep, void *obj, gfp_t flags);
+void bc_slab_uncharge(kmem_cache_t *cachep, void *obj);
+#else
+static inline int __must_check bc_page_charge(struct page *page, int order,
+ gfp_t flags)
+{
+ return 0;
+}
+
+static inline void bc_page_uncharge(struct page *page, int order)
+{
+}
+
+static inline int __must_check bc_slab_charge(kmem_cache_t *cachep, void *obj,
+ gfp_t flags)
+{
+ return 0;
+}
+
+static inline void bc_slab_uncharge(kmem_cache_t *cachep, void *obj)
+{
+}
+#endif
+#endif /* __BC_SLAB_H_ */
--- ./include/linux/gfp.h.bc_kmem_core 2006-10-05 11:42:43.000000000 +0400
+++ ./include/linux/gfp.h 2006-10-05 12:12:24.000000000 +0400
@@ -46,15 +46,18 @@ struct vm_area_struct;
#define __GFP_NOMEMALLOC ((__force gfp_t)0x10000u) /* Don't use emergency reserves */
#define __GFP_HARDWALL ((__force gfp_t)0x20000u) /* Enforce hardwall cpuset memory allocs */
#define __GFP_THISNODE ((__force gfp_t)0x40000u)/* No fallback, no policies */
+#define __GFP_BC ((__force gfp_t)0x80000u) /* Charge allocation with BC */
+#define __GFP_BC_LIMIT ((__force gfp_t)0x100000u) /* Charge against BC limit */

-#define __GFP_BITS_SHIFT 20 /* Room for 20 __GFP_FOO bits */
+#define __GFP_BITS_SHIFT 21 /* Room for 21 __GFP_FOO bits */
#define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))

/* if you forget to add the bitmask here kernel will crash, period */
#define GFP_LEVEL_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS| \
__GFP_COLD|__GFP_NOWARN|__GFP_REPEAT| \
__GFP_NOFAIL|__GFP_NORETRY|__GFP_NO_GROW|__GFP_COMP| \
- __GFP_NOMEMALLOC|__GFP_HARDWALL|__GFP_THISNODE)
+ __GFP_NOMEMALLOC|__GFP_HARDWALL|__GFP_THISNODE| \
+ __GFP_BC|__GFP_BC_LIMIT)

/* This equals 0, but use constants in case they ever change */
#define GFP_NOWAIT (GFP_ATOMIC & ~__GFP_HIGH)
@@ -63,6 +66,7 @@ struct vm_area_struct;
#define GFP_NOIO (__GFP_WAIT)
#define GFP_NOFS (__GFP_WAIT | __GFP_IO)
#define GFP_KERNEL (__GFP_WAIT | __GFP_IO | __GFP_FS)
+#define GFP_KERNEL_BC (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_BC)
#define GFP_USER (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
#define GFP_HIGHUSER (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL | \
__GFP_HIGHMEM)
--- ./include/linux/mm.h.bc_kmem_core 2006-10-05 11:42:43.000000000 +0400
+++ ./include/linux/mm.h 2006-10-05 12:12:24.000000000 +0400
@@ -219,6 +219,7 @@ struct vm_operations_struct {
struct mmu_gather;
struct inode;

+#define page_bc(page) ((page)->bc)
#define page_private(page) ((page)->private)
#define set_page_private(page, v) ((page)->private = (v))

--- ./include/linux/mm_types.h.bc_kmem_core 2006-10-05 11:42:43.000000000 +0400
+++ ./include/linux/mm_types.h 2006-10-05 12:12:24.000000000 +0400
@@ -62,6 +62,9 @@ struct page {
void *virtual; /* Kernel virtual address (NULL if
not kmapped, ie. highmem) */
#endif /* WANT_PAGE_VIRTUAL */
+#ifdef CONFIG_BEANCOUNTERS
+ struct beancounter *bc;
+#endif
#ifdef CONFIG_PAGE_OWNER
int order;
unsigned int gfp_mask;
--- ./include/linux/slab.h.bc_kmem_core 2006-10-05 11:42:43.000000000 +0400
+++ ./include/linux/slab.h 2006-10-05 12:12:24.000000000 +0400
@@ -46,6 +46,8 @@ typedef struct kmem_cache kmem_cache_t;
#define SLAB_PANIC 0x00040000UL /* panic if kmem_cache_create() fails */
#define SLAB_DESTROY_BY_RCU 0x00080000UL /* defer freeing pages to RCU */
#define SLAB_MEM_SPREAD 0x00100000UL /* Spread some memory over cpuset */
+#define SLAB_BC 0x00200000UL /* Account with BC */
+#define SLAB_BC_NOCHARGE 0x00400000UL /* Explicit accounting */

/* flags passed to a constructor func */
#define SLAB_CTOR_CONSTRUCTOR 0x001UL /* if not set, then deconstructor */
@@ -305,6 +307,8 @@ extern kmem_cache_t *fs_cachep;
extern kmem_cache_t *sighand_cachep;
extern kmem_cache_t *bio_cachep;

+struct beancounter;
+struct beancounter **kmem_cache_bcp(kmem_cache_t *cachep, void *obj);
#endif /* __KERNEL__ */

#endif /* _LINUX_SLAB_H */
--- ./include/linux/vmalloc.h.bc_kmem_core 2006-10-05 11:42:43.000000000 +0400
+++ ./include/linux/vmalloc.h 2006-10-05 12:12:24.000000000 +0400
@@ -36,6 +36,7 @@ struct vm_struct {
* Highlevel APIs for driver use
*/
extern void *vmalloc(unsigned long size);
+extern void *vmalloc_bc(unsigned long size);
extern void *vmalloc_user(unsigned long size);
extern void *vmalloc_node(unsigned long size, int node);
extern void *vmalloc_exec(unsigned long size);
--- /dev/null 2006-07-18 14:52:43.075228448 +0400
+++ ./kernel/bc/kmem.c 2006-10-05 12:13:35.000000000 +0400
@@ -0,0 +1,112 @@
+/*
+ * kernel/bc/kmem.c
+ *
+ * Copyright (C) 2006 OpenVZ SWsoft Inc
+ *
+ */
+
+#include <linux/sched.h>
+#include <linux/gfp.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+
+#include <bc/beancounter.h>
+#include <bc/kmem.h>
+#include <bc/task.h>
+
+#define BC_KMEMSIZE_BARRIER (64 * 1024)
+#define BC_KMEMSIZE_LIMIT (64 * 1024)
+
+/*
+ * Slab accounting
+ */
+
+int bc_slab_charge(kmem_cache_t *cachep, void *objp, gfp_t flags)
+{
+ unsigned int size;
+ struct beancounter *bc, **slab_bcp;
+
+ bc = get_exec_bc();
+
+ size = kmem_cache_size(cachep);
+ if (bc_charge(bc, BC_KMEMSIZE, size,
+ (flags & __GFP_BC_LIMIT ? BC_LIMIT : BC_BARRIER)))
+ return -ENOMEM;
+
+ slab_bcp = kmem_cache_bcp(cachep, objp);
+ BUG_ON(*slab_bcp != NULL);
+ *slab_bcp = bc_get(bc);
+ return 0;
+}
+
+void bc_slab_uncharge(kmem_cache_t *cachep, void *objp)
+{
+ unsigned int size;
+ struct beancounter *bc, **slab_bcp;
+
+ slab_bcp = kmem_cache_bcp(cachep, objp);
+ if (*slab_bcp == NULL)
+ return;
+
+ bc = *slab_bcp;
+ size = kmem_cache_size(cachep);
+ bc_uncharge(bc, BC_KMEMSIZE, size);
+ bc_put(bc);
+ *slab_bcp = NULL;
+}
+
+/*
+ * Pages accounting
+ */
+
+int bc_page_charge(struct page *page, int order, gfp_t flags)
+{
+ struct beancounter *bc;
+
+ bc = get_exec_bc();
+
+ if (bc_charge(bc, BC_KMEMSIZE, PAGE_SIZE << order,
+ (flags & __GFP_BC_LIMIT ? BC_LIMIT : BC_BARRIER)))
+ return -ENOMEM;
+
+ BUG_ON(page_bc(page) != NULL);
+ page_bc(page) = bc_get(bc);
+ return 0;
+}
+
+void bc_page_uncharge(struct page *page, int order)
+{
+ struct beancounter *bc;
+
+ bc = page_bc(page);
+ if (bc == NULL)
+ return;
+
+ bc_uncharge(bc, BC_KMEMSIZE, PAGE_SIZE << order);
+ bc_put(bc);
+ page_bc(page) = NULL;
+}
+
+/*
+ * Generic resource info
+ */
+
+static int bc_kmem_init(struct beancounter *bc, gfp_t mask)
+{
+ bc_init_resource(bc, BC_KMEMSIZE,
+ BC_KMEMSIZE_BARRIER, BC_KMEMSIZE_LIMIT);
+ return 0;
+}
+
+struct bc_resource bc_kmem_resource = {
+ .bcr_name = "kmemsize",
+ .bcr_init = bc_kmem_init,
+};
+
+static int __init bc_kmem_init_resource(void)
+{
+ bc_register_resource(BC_KMEMSIZE, &bc_kmem_resource);
+ return 0;
+}
+
+__initcall(bc_kmem_init_resource);
--- ./mm/mempool.c.bc_kmem_core 2006-09-20 14:46:41.000000000 +0400
+++ ./mm/mempool.c 2006-10-05 12:12:24.000000000 +0400
@@ -119,6 +119,7 @@ int mempool_resize(mempool_t *pool, int
unsigned long flags;

BUG_ON(new_min_nr <= 0);
+ gfp_mask &= ~__GFP_BC;

spin_lock_irqsave(&pool->lock, flags);
if (new_min_nr <= pool->min_nr) {
@@ -212,6 +213,7 @@ void * mempool_alloc(mempool_t *pool, gf
gfp_mask |= __GFP_NOMEMALLOC; /* don't allocate emergency reserves */
gfp_mask |= __GFP_NORETRY; /* don't loop in __alloc_pages */
gfp_mask |= __GFP_NOWARN; /* failures are OK */
+ gfp_mask &= ~__GFP_BC; /* do not charge */

gfp_temp = gfp_mask & ~(__GFP_WAIT|__GFP_IO);

--- ./mm/page_alloc.c.bc_kmem_core 2006-10-05 11:42:43.000000000 +0400
+++ ./mm/page_alloc.c 2006-10-05 12:12:24.000000000 +0400
@@ -40,6 +40,8 @@
#include <linux/sort.h>
#include <linux/pfn.h>

+#include <bc/kmem.h>
+
#include <asm/tlbflush.h>
#include <asm/div64.h>
#include "internal.h"
@@ -517,6 +519,8 @@ static void __free_pages_ok(struct page
if (reserved)
return;

+ bc_page_uncharge(page, order);
+
kernel_map_pages(page, 1 << order, 0);
local_irq_save(flags);
__count_vm_events(PGFREE, 1 << order);
@@ -800,6 +804,8 @@ static void fastcall free_hot_cold_page(
if (free_pages_check(page))
return;

+ bc_page_uncharge(page, 0);
+
kernel_map_pages(page, 1, 0);

pcp = &zone_pcp(zone, get_cpu())->pcp[cold];
@@ -1190,6 +1196,11 @@ nopage:
show_mem();
}
got_pg:
+ if ((gfp_mask & __GFP_BC) &&
+ bc_page_charge(page, order, gfp_mask)) {
+ __free_pages(page, order);
+ page = NULL;
+ }
#ifdef CONFIG_PAGE_OWNER
if (page)
set_page_owner(page, order, gfp_mask);
--- ./mm/slab.c.bc_kmem_core 2006-10-05 11:42:43.000000000 +0400
+++ ./mm/slab.c 2006-10-05 12:12:24.000000000 +0400
@@ -108,6 +108,8 @@
#include <linux/mutex.h>
#include <linux/rtmutex.h>

+#include <bc/kmem.h>
+
#include <asm/uaccess.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
@@ -175,11 +177,13 @@
SLAB_CACHE_DMA | \
SLAB_MUST_HWCACHE_ALIGN | SLAB_STORE_USER | \
SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
+ SLAB_BC | SLAB_BC_NOCHARGE | \
SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD)
#else
# define CREATE_MASK (SLAB_HWCACHE_ALIGN | \
SLAB_CACHE_DMA | SLAB_MUST_HWCACHE_ALIGN | \
SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
+ SLAB_BC | SLAB_BC_NOCHARGE | \
SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD)
#endif

@@ -793,9 +797,33 @@ static struct kmem_cache *kmem_find_gene
return __find_general_cachep(size, gfpflags);
}

-static size_t slab_mgmt_size(size_t nr_objs, size_t align)
+static size_t slab_mgmt_size_raw(size_t nr_objs)
{
- return ALIGN(sizeof(struct slab)+nr_objs*sizeof(kmem_bufctl_t), align);
+ return sizeof(struct slab) + nr_objs * sizeof(kmem_bufctl_t);
+}
+
+#ifdef CONFIG_BEANCOUNTERS
+#define BC_EXTRASIZE sizeof(struct beancounter *)
+static inline size_t slab_mgmt_size_noalign(int flags, size_t nr_objs)
+{
+ size_t size;
+
+ size = slab_mgmt_size_raw(nr_objs);
+ if (flags & SLAB_BC)
+ size = ALIGN(size, BC_EXTRASIZE) + nr_objs * BC_EXTRASIZE;
+ return size;
+}
+#else
+#define BC_EXTRASIZE 0
+static inline size_t slab_mgmt_size_noalign(int flags, size_t nr_objs)
+{
+ return slab_mgmt_size_raw(nr_objs);
+}
+#endif
+
+static inline size_t slab_mgmt_size(int flags, size_t nr_objs, size_t align)
+{
+ return ALIGN(slab_mgmt_size_noalign(flags, nr_objs), align);
}

/*
@@ -840,20 +868,21 @@ static void cache_estimate(unsigned long
* into account.
*/
nr_objs = (slab_size - sizeof(struct slab)) /
- (buffer_size + sizeof(kmem_bufctl_t));
+ (buffer_size + sizeof(kmem_bufctl_t) +
+ (flags & SLAB_BC ? BC_EXTRASIZE : 0));

/*
* This calculated number will be either the right
* amount, or one greater than what we want.
*/
- if (slab_mgmt_size(nr_objs, align) + nr_objs*buffer_size
+ if (slab_mgmt_size(flags, nr_objs, align) + nr_objs*buffer_size
> slab_size)
nr_objs--;

if (nr_objs > SLAB_LIMIT)
nr_objs = SLAB_LIMIT;

- mgmt_size = slab_mgmt_size(nr_objs, align);
+ mgmt_size = slab_mgmt_size(flags, nr_objs, align);
}
*num = nr_objs;
*left_over = slab_size - nr_objs*buffer_size - mgmt_size;
@@ -1965,7 +1994,8 @@ static size_t calculate_slab_order(struc
* looping condition in cache_grow().
*/
offslab_limit = size - sizeof(struct slab);
- offslab_limit /= sizeof(kmem_bufctl_t);
+ offslab_limit /= (sizeof(kmem_bufctl_t) +
+ (flags & SLAB_BC ? BC_EXTRASIZE : 0));

if (num > offslab_limit)
break;
@@ -2273,8 +2303,8 @@ kmem_cache_create (const char *name, siz
cachep = NULL;
goto oops;
}
- slab_size = ALIGN(cachep->num * sizeof(kmem_bufctl_t)
- + sizeof(struct slab), align);
+
+ slab_size = slab_mgmt_size(flags, cachep->num, align);

/*
* If the slab has been placed off-slab, and we have enough space then
@@ -2285,11 +2315,9 @@ kmem_cache_create (const char *name, siz
left_over -= slab_size;
}

- if (flags & CFLGS_OFF_SLAB) {
+ if (flags & CFLGS_OFF_SLAB)
/* really off slab. No need for manual alignment */
- slab_size =
- cachep->num * sizeof(kmem_bufctl_t) + sizeof(struct slab);
- }
+ slab_size = slab_mgmt_size_noalign(flags, cachep->num);

cachep->colour_off = cache_line_size();
/* Offset must be a multiple of the alignment. */
@@ -2535,6 +2563,30 @@ void kmem_cache_destroy(struct kmem_cach
}
EXPORT_SYMBOL(kmem_cache_destroy);

+static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp)
+{
+ return (kmem_bufctl_t *) (slabp + 1);
+}
+
+#ifdef CONFIG_BEANCOUNTERS
+static inline struct beancounter **slab_bc_ptrs(kmem_cache_t *cachep,
+ struct slab *slabp)
+{
+ return (struct beancounter **) ALIGN((unsigned long)
+ (slab_bufctl(slabp) + cachep->num), BC_EXTRASIZE);
+}
+
+struct beancounter **kmem_cache_bcp(kmem_cache_t *cachep, void *objp)
+{
+ struct slab *slabp;
+ struct beancounter **bcs;
+
+ slabp = virt_to_slab(objp);
+ bcs = slab_bc_ptrs(cachep, slabp);
+ return bcs + obj_to_index(cachep, slabp, objp);
+}
+#endif
+
/*
* Get the memory for a slab management obj.
* For a slab cache when the slab descriptor is off-slab, slab descriptors
@@ -2555,7 +2607,8 @@ static struct slab *alloc_slabmgmt(struc
if (OFF_SLAB(cachep)) {
/* Slab management obj is off-slab. */
slabp = kmem_cache_alloc_node(cachep->slabp_cache,
- local_flags, nodeid);
+ local_flags & (~__GFP_BC),
+ nodeid);
if (!slabp)
return NULL;
} else {
@@ -2566,14 +2619,14 @@ static struct slab *alloc_slabmgmt(struc
slabp->colouroff = colour_off;
slabp->s_mem = objp + colour_off;
slabp->nodeid = nodeid;
+#ifdef CONFIG_BEANCOUNTERS
+ if (cachep->flags & SLAB_BC)
+ memset(slab_bc_ptrs(cachep, slabp), 0,
+ cachep->num * BC_EXTRASIZE);
+#endif
return slabp;
}

-static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp)
-{
- return (kmem_bufctl_t *) (slabp + 1);
-}
-
static void cache_init_objs(struct kmem_cache *cachep,
struct slab *slabp, unsigned long ctor_flags)
{
@@ -2751,7 +2804,7 @@ static int cache_grow(struct kmem_cache
* Get mem for the objs. Attempt to allocate a physical page from
* 'nodeid'.
*/
- objp = kmem_getpages(cachep, flags, nodeid);
+ objp = kmem_getpages(cachep, flags & (~__GFP_BC), nodeid);
if (!objp)
goto failed;

@@ -3094,6 +3147,19 @@ static inline void *____cache_alloc(stru
return objp;
}

+static inline int bc_should_charge(kmem_cache_t *cachep, gfp_t flags)
+{
+#ifdef CONFIG_BEANCOUNTERS
+ if (!(cachep->flags & SLAB_BC))
+ return 0;
+ if (flags & __GFP_BC)
+ return 1;
+ if (!(cachep->flags & SLAB_BC_NOCHARGE))
+ return 1;
+#endif
+ return 0;
+}
+
static __always_inline void *__cache_alloc(struct kmem_cache *cachep,
gfp_t flags, void *caller)
{
@@ -3119,6 +3185,12 @@ static __always_inline void *__cache_all
local_irq_restore(save_flags);
objp = cache_alloc_debugcheck_after(cachep, flags, objp,
caller);
+
+ if (objp && bc_should_charge(cachep, flags))
+ if (bc_slab_charge(cachep, objp, flags)) {
+ kmem_cache_free(cachep, objp);
+ objp = NULL;
+ }
prefetchw(objp);
return objp;
}
@@ -3342,6 +3414,8 @@ static inline void __cache_free(struct k
struct array_cache *ac = cpu_cache_get(cachep);

check_irq_off();
+ if (cachep->flags & SLAB_BC)
+ bc_slab_uncharge(cachep, objp);
objp = cache_free_debugcheck(cachep, objp, __builtin_return_address(0));

if (cache_free_alien(cachep, objp))
--- ./mm/vmalloc.c.bc_kmem_core 2006-10-05 11:42:43.000000000 +0400
+++ ./mm/vmalloc.c 2006-10-05 12:12:24.000000000 +0400
@@ -512,6 +512,12 @@ void *vmalloc(unsigned long size)
}
EXPORT_SYMBOL(vmalloc);

+void *vmalloc_bc(unsigned long size)
+{
+ return __vmalloc(size, GFP_KERNEL_BC | __GFP_HIGHMEM, PAGE_KERNEL);
+}
+EXPORT_SYMBOL(vmalloc_bc);
+
/**
* vmalloc_user - allocate zeroed virtually contiguous memory for userspace
* @size: allocation size