Linux-mm Archive on lore.kernel.org
 help / color / Atom feed
From: Matthew Wilcox <willy@infradead.org>
To: linux-mm@kvack.org
Cc: "Matthew Wilcox" <mawilcox@microsoft.com>,
	"Andrew Morton" <akpm@linux-foundation.org>,
	"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
	"Christoph Lameter" <cl@linux.com>,
	"Lai Jiangshan" <jiangshanlai@gmail.com>,
	"Pekka Enberg" <penberg@kernel.org>,
	"Vlastimil Babka" <vbabka@suse.cz>,
	"Dave Hansen" <dave.hansen@linux.intel.com>,
	"Jérôme Glisse" <jglisse@redhat.com>
Subject: [PATCH v6 15/17] slub: Remove kmem_cache->reserved
Date: Fri, 18 May 2018 12:45:17 -0700
Message-ID: <20180518194519.3820-16-willy@infradead.org> (raw)
In-Reply-To: <20180518194519.3820-1-willy@infradead.org>

From: Matthew Wilcox <mawilcox@microsoft.com>

The reserved field was only used for embedding an rcu_head in the data
structure.  With the previous commit, we no longer need it.  That lets
us remove the 'reserved' argument to a lot of functions.

Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Christoph Lameter <cl@linux.com>
---
 include/linux/slub_def.h |  1 -
 mm/slub.c                | 41 ++++++++++++++++++++--------------------
 2 files changed, 20 insertions(+), 22 deletions(-)

diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
index 3773e26c08c1..09fa2c6f0e68 100644
--- a/include/linux/slub_def.h
+++ b/include/linux/slub_def.h
@@ -101,7 +101,6 @@ struct kmem_cache {
 	void (*ctor)(void *);
 	unsigned int inuse;		/* Offset to metadata */
 	unsigned int align;		/* Alignment */
-	unsigned int reserved;		/* Reserved bytes at the end of slabs */
 	unsigned int red_left_pad;	/* Left redzone padding size */
 	const char *name;	/* Name (only for display!) */
 	struct list_head list;	/* List of slab caches */
diff --git a/mm/slub.c b/mm/slub.c
index 8e2407f69855..33a811168fa9 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -316,16 +316,16 @@ static inline unsigned int slab_index(void *p, struct kmem_cache *s, void *addr)
 	return (p - addr) / s->size;
 }
 
-static inline unsigned int order_objects(unsigned int order, unsigned int size, unsigned int reserved)
+static inline unsigned int order_objects(unsigned int order, unsigned int size)
 {
-	return (((unsigned int)PAGE_SIZE << order) - reserved) / size;
+	return ((unsigned int)PAGE_SIZE << order) / size;
 }
 
 static inline struct kmem_cache_order_objects oo_make(unsigned int order,
-		unsigned int size, unsigned int reserved)
+		unsigned int size)
 {
 	struct kmem_cache_order_objects x = {
-		(order << OO_SHIFT) + order_objects(order, size, reserved)
+		(order << OO_SHIFT) + order_objects(order, size)
 	};
 
 	return x;
@@ -832,7 +832,7 @@ static int slab_pad_check(struct kmem_cache *s, struct page *page)
 		return 1;
 
 	start = page_address(page);
-	length = (PAGE_SIZE << compound_order(page)) - s->reserved;
+	length = PAGE_SIZE << compound_order(page);
 	end = start + length;
 	remainder = length % s->size;
 	if (!remainder)
@@ -921,7 +921,7 @@ static int check_slab(struct kmem_cache *s, struct page *page)
 		return 0;
 	}
 
-	maxobj = order_objects(compound_order(page), s->size, s->reserved);
+	maxobj = order_objects(compound_order(page), s->size);
 	if (page->objects > maxobj) {
 		slab_err(s, page, "objects %u > max %u",
 			page->objects, maxobj);
@@ -971,7 +971,7 @@ static int on_freelist(struct kmem_cache *s, struct page *page, void *search)
 		nr++;
 	}
 
-	max_objects = order_objects(compound_order(page), s->size, s->reserved);
+	max_objects = order_objects(compound_order(page), s->size);
 	if (max_objects > MAX_OBJS_PER_PAGE)
 		max_objects = MAX_OBJS_PER_PAGE;
 
@@ -3188,21 +3188,21 @@ static unsigned int slub_min_objects;
  */
 static inline unsigned int slab_order(unsigned int size,
 		unsigned int min_objects, unsigned int max_order,
-		unsigned int fract_leftover, unsigned int reserved)
+		unsigned int fract_leftover)
 {
 	unsigned int min_order = slub_min_order;
 	unsigned int order;
 
-	if (order_objects(min_order, size, reserved) > MAX_OBJS_PER_PAGE)
+	if (order_objects(min_order, size) > MAX_OBJS_PER_PAGE)
 		return get_order(size * MAX_OBJS_PER_PAGE) - 1;
 
-	for (order = max(min_order, (unsigned int)get_order(min_objects * size + reserved));
+	for (order = max(min_order, (unsigned int)get_order(min_objects * size));
 			order <= max_order; order++) {
 
 		unsigned int slab_size = (unsigned int)PAGE_SIZE << order;
 		unsigned int rem;
 
-		rem = (slab_size - reserved) % size;
+		rem = slab_size % size;
 
 		if (rem <= slab_size / fract_leftover)
 			break;
@@ -3211,7 +3211,7 @@ static inline unsigned int slab_order(unsigned int size,
 	return order;
 }
 
-static inline int calculate_order(unsigned int size, unsigned int reserved)
+static inline int calculate_order(unsigned int size)
 {
 	unsigned int order;
 	unsigned int min_objects;
@@ -3228,7 +3228,7 @@ static inline int calculate_order(unsigned int size, unsigned int reserved)
 	min_objects = slub_min_objects;
 	if (!min_objects)
 		min_objects = 4 * (fls(nr_cpu_ids) + 1);
-	max_objects = order_objects(slub_max_order, size, reserved);
+	max_objects = order_objects(slub_max_order, size);
 	min_objects = min(min_objects, max_objects);
 
 	while (min_objects > 1) {
@@ -3237,7 +3237,7 @@ static inline int calculate_order(unsigned int size, unsigned int reserved)
 		fraction = 16;
 		while (fraction >= 4) {
 			order = slab_order(size, min_objects,
-					slub_max_order, fraction, reserved);
+					slub_max_order, fraction);
 			if (order <= slub_max_order)
 				return order;
 			fraction /= 2;
@@ -3249,14 +3249,14 @@ static inline int calculate_order(unsigned int size, unsigned int reserved)
 	 * We were unable to place multiple objects in a slab. Now
 	 * lets see if we can place a single object there.
 	 */
-	order = slab_order(size, 1, slub_max_order, 1, reserved);
+	order = slab_order(size, 1, slub_max_order, 1);
 	if (order <= slub_max_order)
 		return order;
 
 	/*
 	 * Doh this slab cannot be placed using slub_max_order.
 	 */
-	order = slab_order(size, 1, MAX_ORDER, 1, reserved);
+	order = slab_order(size, 1, MAX_ORDER, 1);
 	if (order < MAX_ORDER)
 		return order;
 	return -ENOSYS;
@@ -3524,7 +3524,7 @@ static int calculate_sizes(struct kmem_cache *s, int forced_order)
 	if (forced_order >= 0)
 		order = forced_order;
 	else
-		order = calculate_order(size, s->reserved);
+		order = calculate_order(size);
 
 	if ((int)order < 0)
 		return 0;
@@ -3542,8 +3542,8 @@ static int calculate_sizes(struct kmem_cache *s, int forced_order)
 	/*
 	 * Determine the number of objects per slab
 	 */
-	s->oo = oo_make(order, size, s->reserved);
-	s->min = oo_make(get_order(size), size, s->reserved);
+	s->oo = oo_make(order, size);
+	s->min = oo_make(get_order(size), size);
 	if (oo_objects(s->oo) > oo_objects(s->max))
 		s->max = s->oo;
 
@@ -3553,7 +3553,6 @@ static int calculate_sizes(struct kmem_cache *s, int forced_order)
 static int kmem_cache_open(struct kmem_cache *s, slab_flags_t flags)
 {
 	s->flags = kmem_cache_flags(s->size, flags, s->name, s->ctor);
-	s->reserved = 0;
 #ifdef CONFIG_SLAB_FREELIST_HARDENED
 	s->random = get_random_long();
 #endif
@@ -5097,7 +5096,7 @@ SLAB_ATTR_RO(destroy_by_rcu);
 
 static ssize_t reserved_show(struct kmem_cache *s, char *buf)
 {
-	return sprintf(buf, "%u\n", s->reserved);
+	return sprintf(buf, "0\n");
 }
 SLAB_ATTR_RO(reserved);
 
-- 
2.17.0

  parent reply index

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-18 19:45 [PATCH v6 00/17] Rearrange struct page Matthew Wilcox
2018-05-18 19:45 ` [PATCH v6 01/17] s390: Use _refcount for pgtables Matthew Wilcox
2018-05-18 19:45 ` [PATCH v6 02/17] mm: Split page_type out from _mapcount Matthew Wilcox
2018-05-18 19:45 ` [PATCH v6 03/17] mm: Mark pages in use for page tables Matthew Wilcox
2018-05-18 19:45 ` [PATCH v6 04/17] mm: Switch s_mem and slab_cache in struct page Matthew Wilcox
2018-05-18 19:45 ` [PATCH v6 05/17] mm: Move 'private' union within " Matthew Wilcox
2018-05-18 19:45 ` [PATCH v6 06/17] mm: Move _refcount out of struct page union Matthew Wilcox
2018-05-18 19:45 ` [PATCH v6 07/17] mm: Combine first three unions in struct page Matthew Wilcox
2018-05-18 19:45 ` [PATCH v6 08/17] mm: Use page->deferred_list Matthew Wilcox
2018-05-18 19:45 ` [PATCH v6 09/17] mm: Move lru union within struct page Matthew Wilcox
2018-05-18 19:45 ` [PATCH v6 10/17] mm: Combine LRU and main union in " Matthew Wilcox
2018-05-18 19:45 ` [PATCH v6 11/17] mm: Improve struct page documentation Matthew Wilcox
2018-05-18 19:45 ` [PATCH v6 12/17] mm: Add pt_mm to struct page Matthew Wilcox
2018-05-18 19:45 ` [PATCH v6 13/17] mm: Add hmm_data " Matthew Wilcox
2018-05-18 19:45 ` [PATCH v6 14/17] slab,slub: Remove rcu_head size checks Matthew Wilcox
2018-05-18 19:45 ` Matthew Wilcox [this message]
2018-05-18 19:45 ` [PATCH v6 16/17] slub: Remove 'reserved' file from sysfs Matthew Wilcox
2018-05-18 19:45 ` [PATCH v6 17/17] mm: Distinguish VMalloc pages Matthew Wilcox
2018-05-22 16:10   ` Andrey Ryabinin
2018-05-22 17:58     ` Matthew Wilcox
2018-05-22 19:49       ` Andrew Morton
2018-05-22 19:57       ` Andrey Ryabinin
2018-05-22 20:19         ` Matthew Wilcox
2018-05-22 20:48           ` Andrew Morton
2018-05-22 21:45             ` Matthew Wilcox
2018-05-22 23:02               ` Andrew Morton
2018-05-23  6:36           ` Michal Hocko
2018-05-23  6:34         ` Michal Hocko
2018-05-23  9:14           ` Andrey Ryabinin
2018-05-23  9:25             ` Michal Hocko
2018-05-23  9:28               ` Andrey Ryabinin
2018-05-23  9:52                 ` Michal Hocko

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180518194519.3820-16-willy@infradead.org \
    --to=willy@infradead.org \
    --cc=akpm@linux-foundation.org \
    --cc=cl@linux.com \
    --cc=dave.hansen@linux.intel.com \
    --cc=jglisse@redhat.com \
    --cc=jiangshanlai@gmail.com \
    --cc=kirill.shutemov@linux.intel.com \
    --cc=linux-mm@kvack.org \
    --cc=mawilcox@microsoft.com \
    --cc=penberg@kernel.org \
    --cc=vbabka@suse.cz \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-mm Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-mm/0 linux-mm/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-mm linux-mm/ https://lore.kernel.org/linux-mm \
		linux-mm@kvack.org
	public-inbox-index linux-mm

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kvack.linux-mm


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git