2005-11-03 23:06:04

by Matt Mackall

[permalink] [raw]
Subject: [PATCH 1/2] slob: introduce mm/util.c for shared functions

Add mm/util.c for functions common between SLAB and SLOB.

Signed-off-by: Matt Mackall <[email protected]>

Index: 2.6.14-slob/mm/Makefile
===================================================================
--- 2.6.14-slob.orig/mm/Makefile 2005-11-03 14:40:31.000000000 -0800
+++ 2.6.14-slob/mm/Makefile 2005-11-03 14:48:17.000000000 -0800
@@ -10,7 +10,7 @@ mmu-$(CONFIG_MMU) := fremap.o highmem.o
obj-y := bootmem.o filemap.o mempool.o oom_kill.o fadvise.o \
page_alloc.o page-writeback.o pdflush.o \
readahead.o slab.o swap.o truncate.o vmscan.o \
- prio_tree.o $(mmu-y)
+ prio_tree.o util.o $(mmu-y)

obj-$(CONFIG_SWAP) += page_io.o swap_state.o swapfile.o thrash.o
obj-$(CONFIG_HUGETLBFS) += hugetlb.o
Index: 2.6.14-slob/mm/slab.c
===================================================================
--- 2.6.14-slob.orig/mm/slab.c 2005-11-03 14:40:32.000000000 -0800
+++ 2.6.14-slob/mm/slab.c 2005-11-03 14:47:04.000000000 -0800
@@ -2994,20 +2994,6 @@ void kmem_cache_free(kmem_cache_t *cache
EXPORT_SYMBOL(kmem_cache_free);

/**
- * kzalloc - allocate memory. The memory is set to zero.
- * @size: how many bytes of memory are required.
- * @flags: the type of memory to allocate.
- */
-void *kzalloc(size_t size, gfp_t flags)
-{
- void *ret = kmalloc(size, flags);
- if (ret)
- memset(ret, 0, size);
- return ret;
-}
-EXPORT_SYMBOL(kzalloc);
-
-/**
* kfree - free previously allocated memory
* @objp: pointer returned by kmalloc.
*
@@ -3598,24 +3584,3 @@ unsigned int ksize(const void *objp)
}


-/*
- * kstrdup - allocate space for and copy an existing string
- *
- * @s: the string to duplicate
- * @gfp: the GFP mask used in the kmalloc() call when allocating memory
- */
-char *kstrdup(const char *s, gfp_t gfp)
-{
- size_t len;
- char *buf;
-
- if (!s)
- return NULL;
-
- len = strlen(s) + 1;
- buf = kmalloc(len, gfp);
- if (buf)
- memcpy(buf, s, len);
- return buf;
-}
-EXPORT_SYMBOL(kstrdup);
Index: 2.6.14-slob/mm/util.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ 2.6.14-slob/mm/util.c 2005-11-03 14:47:02.000000000 -0800
@@ -0,0 +1,39 @@
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/module.h>
+
+/**
+ * kzalloc - allocate memory. The memory is set to zero.
+ * @size: how many bytes of memory are required.
+ * @flags: the type of memory to allocate.
+ */
+void *kzalloc(size_t size, gfp_t flags)
+{
+ void *ret = kmalloc(size, flags);
+ if (ret)
+ memset(ret, 0, size);
+ return ret;
+}
+EXPORT_SYMBOL(kzalloc);
+
+/*
+ * kstrdup - allocate space for and copy an existing string
+ *
+ * @s: the string to duplicate
+ * @gfp: the GFP mask used in the kmalloc() call when allocating memory
+ */
+char *kstrdup(const char *s, gfp_t gfp)
+{
+ size_t len;
+ char *buf;
+
+ if (!s)
+ return NULL;
+
+ len = strlen(s) + 1;
+ buf = kmalloc(len, gfp);
+ if (buf)
+ memcpy(buf, s, len);
+ return buf;
+}
+EXPORT_SYMBOL(kstrdup);


2005-11-03 23:06:12

by Matt Mackall

[permalink] [raw]
Subject: [PATCH 2/2] slob: introduce the SLOB allocator

configurable replacement for slab allocator

This adds a CONFIG_SLAB option under CONFIG_EMBEDDED. When CONFIG_SLAB
is disabled, the kernel falls back to using the 'SLOB' allocator.

SLOB is a traditional K&R/UNIX allocator with a SLAB emulation layer,
similar to the original Linux kmalloc allocator that SLAB replaced.
It's signicantly smaller code and is more memory efficient. But like
all similar allocators, it scales poorly and suffers from
fragmentation more than SLAB, so it's only appropriate for small
systems.

It's been tested extensively in the Linux-tiny tree. I've also
stress-tested it with make -j 8 compiles on a 3G SMP+PREEMPT box (not
recommended).

Here's a comparison for otherwise identical builds, showing SLOB
saving nearly half a megabyte of RAM:

$ size vmlinux*
text data bss dec hex filename
3336372 529360 190812 4056544 3de5e0 vmlinux-slab
3323208 527948 190684 4041840 3dac70 vmlinux-slob

$ size mm/{slab,slob}.o
text data bss dec hex filename
13221 752 48 14021 36c5 mm/slab.o
1896 52 8 1956 7a4 mm/slob.o

/proc/meminfo:
SLAB SLOB delta
MemTotal: 27964 kB 27980 kB +16 kB
MemFree: 24596 kB 25092 kB +496 kB
Buffers: 36 kB 36 kB 0 kB
Cached: 1188 kB 1188 kB 0 kB
SwapCached: 0 kB 0 kB 0 kB
Active: 608 kB 600 kB -8 kB
Inactive: 808 kB 812 kB +4 kB
HighTotal: 0 kB 0 kB 0 kB
HighFree: 0 kB 0 kB 0 kB
LowTotal: 27964 kB 27980 kB +16 kB
LowFree: 24596 kB 25092 kB +496 kB
SwapTotal: 0 kB 0 kB 0 kB
SwapFree: 0 kB 0 kB 0 kB
Dirty: 4 kB 12 kB +8 kB
Writeback: 0 kB 0 kB 0 kB
Mapped: 560 kB 556 kB -4 kB
Slab: 1756 kB 0 kB -1756 kB
CommitLimit: 13980 kB 13988 kB +8 kB
Committed_AS: 4208 kB 4208 kB 0 kB
PageTables: 28 kB 28 kB 0 kB
VmallocTotal: 1007312 kB 1007312 kB 0 kB
VmallocUsed: 48 kB 48 kB 0 kB
VmallocChunk: 1007264 kB 1007264 kB 0 kB

(this work has been sponsored in part by CELF)

Signed-off-by: Matt Mackall <[email protected]>

Index: 2.6.14-slob/mm/slob.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ 2.6.14-slob/mm/slob.c 2005-11-03 14:55:45.000000000 -0800
@@ -0,0 +1,385 @@
+/*
+ * SLOB Allocator: Simple List Of Blocks
+ *
+ * Matt Mackall <[email protected]> 12/30/03
+ *
+ * How SLOB works:
+ *
+ * The core of SLOB is a traditional K&R style heap allocator, with
+ * support for returning aligned objects. The granularity of this
+ * allocator is 8 bytes on x86, though it's perhaps possible to reduce
+ * this to 4 if it's deemed worth the effort. The slob heap is a
+ * singly-linked list of pages from __get_free_page, grown on demand
+ * and allocation from the heap is currently first-fit.
+ *
+ * Above this is an implementation of kmalloc/kfree. Blocks returned
+ * from kmalloc are 8-byte aligned and prepended with a 8-byte header.
+ * If kmalloc is asked for objects of PAGE_SIZE or larger, it calls
+ * __get_free_pages directly so that it can return page-aligned blocks
+ * and keeps a linked list of such pages and their orders. These
+ * objects are detected in kfree() by their page alignment.
+ *
+ * SLAB is emulated on top of SLOB by simply calling constructors and
+ * destructors for every SLAB allocation. Objects are returned with
+ * the 8-byte alignment unless the SLAB_MUST_HWCACHE_ALIGN flag is
+ * set, in which case the low-level allocator will fragment blocks to
+ * create the proper alignment. Again, objects of page-size or greater
+ * are allocated by calling __get_free_pages. As SLAB objects know
+ * their size, no separate size bookkeeping is necessary and there is
+ * essentially no allocation space overhead.
+ */
+
+#include <linux/config.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/cache.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/timer.h>
+
+struct slob_block {
+ int units;
+ struct slob_block *next;
+};
+typedef struct slob_block slob_t;
+
+#define SLOB_UNIT sizeof(slob_t)
+#define SLOB_UNITS(size) (((size) + SLOB_UNIT - 1)/SLOB_UNIT)
+#define SLOB_ALIGN L1_CACHE_BYTES
+
+struct bigblock {
+ int order;
+ void *pages;
+ struct bigblock *next;
+};
+typedef struct bigblock bigblock_t;
+
+static slob_t arena = { .next = &arena, .units = 1 };
+static slob_t *slobfree = &arena;
+static bigblock_t *bigblocks;
+static DEFINE_SPINLOCK(slob_lock);
+static DEFINE_SPINLOCK(block_lock);
+
+static void slob_free(void *b, int size);
+
+static void *slob_alloc(size_t size, gfp_t gfp, int align)
+{
+ slob_t *prev, *cur, *aligned = 0;
+ int delta = 0, units = SLOB_UNITS(size);
+ unsigned long flags;
+
+ spin_lock_irqsave(&slob_lock, flags);
+ prev = slobfree;
+ for (cur = prev->next; ; prev = cur, cur = cur->next) {
+ if (align) {
+ aligned = (slob_t *)ALIGN((unsigned long)cur, align);
+ delta = aligned - cur;
+ }
+ if (cur->units >= units + delta) { /* room enough? */
+ if (delta) { /* need to fragment head to align? */
+ aligned->units = cur->units - delta;
+ aligned->next = cur->next;
+ cur->next = aligned;
+ cur->units = delta;
+ prev = cur;
+ cur = aligned;
+ }
+
+ if (cur->units == units) /* exact fit? */
+ prev->next = cur->next; /* unlink */
+ else { /* fragment */
+ prev->next = cur + units;
+ prev->next->units = cur->units - units;
+ prev->next->next = cur->next;
+ cur->units = units;
+ }
+
+ slobfree = prev;
+ spin_unlock_irqrestore(&slob_lock, flags);
+ return cur;
+ }
+ if (cur == slobfree) {
+ spin_unlock_irqrestore(&slob_lock, flags);
+
+ if (size == PAGE_SIZE) /* trying to shrink arena? */
+ return 0;
+
+ cur = (slob_t *)__get_free_page(gfp);
+ if (!cur)
+ return 0;
+
+ slob_free(cur, PAGE_SIZE);
+ spin_lock_irqsave(&slob_lock, flags);
+ cur = slobfree;
+ }
+ }
+}
+
+static void slob_free(void *block, int size)
+{
+ slob_t *cur, *b = (slob_t *)block;
+ unsigned long flags;
+
+ if (!block)
+ return;
+
+ if (size)
+ b->units = SLOB_UNITS(size);
+
+ /* Find reinsertion point */
+ spin_lock_irqsave(&slob_lock, flags);
+ for (cur = slobfree; !(b > cur && b < cur->next); cur = cur->next)
+ if (cur >= cur->next && (b > cur || b < cur->next))
+ break;
+
+ if (b + b->units == cur->next) {
+ b->units += cur->next->units;
+ b->next = cur->next->next;
+ } else
+ b->next = cur->next;
+
+ if (cur + cur->units == b) {
+ cur->units += b->units;
+ cur->next = b->next;
+ } else
+ cur->next = b;
+
+ slobfree = cur;
+
+ spin_unlock_irqrestore(&slob_lock, flags);
+}
+
+static int FASTCALL(find_order(int size));
+static int fastcall find_order(int size)
+{
+ int order = 0;
+ for ( ; size > 4096 ; size >>=1)
+ order++;
+ return order;
+}
+
+void *kmalloc(size_t size, gfp_t gfp)
+{
+ slob_t *m;
+ bigblock_t *bb;
+ unsigned long flags;
+
+ if (size < PAGE_SIZE - SLOB_UNIT) {
+ m = slob_alloc(size + SLOB_UNIT, gfp, 0);
+ return m ? (void *)(m + 1) : 0;
+ }
+
+ bb = slob_alloc(sizeof(bigblock_t), gfp, 0);
+ if (!bb)
+ return 0;
+
+ bb->order = find_order(size);
+ bb->pages = (void *)__get_free_pages(gfp, bb->order);
+
+ if (bb->pages) {
+ spin_lock_irqsave(&block_lock, flags);
+ bb->next = bigblocks;
+ bigblocks = bb;
+ spin_unlock_irqrestore(&block_lock, flags);
+ return bb->pages;
+ }
+
+ slob_free(bb, sizeof(bigblock_t));
+ return 0;
+}
+
+EXPORT_SYMBOL(kmalloc);
+
+void kfree(const void *block)
+{
+ bigblock_t *bb, **last = &bigblocks;
+ unsigned long flags;
+
+ if (!block)
+ return;
+
+ if (!((unsigned int)block & (PAGE_SIZE-1))) {
+ /* might be on the big block list */
+ spin_lock_irqsave(&block_lock, flags);
+ for (bb = bigblocks; bb; last = &bb->next, bb = bb->next) {
+ if (bb->pages == block) {
+ *last = bb->next;
+ spin_unlock_irqrestore(&block_lock, flags);
+ free_pages((unsigned long)block, bb->order);
+ slob_free(bb, sizeof(bigblock_t));
+ return;
+ }
+ }
+ spin_unlock_irqrestore(&block_lock, flags);
+ }
+
+ slob_free((slob_t *)block - 1, 0);
+ return;
+}
+
+EXPORT_SYMBOL(kfree);
+
+unsigned int ksize(const void *block)
+{
+ bigblock_t *bb;
+ unsigned long flags;
+
+ if (!block)
+ return 0;
+
+ if (!((unsigned int)block & (PAGE_SIZE-1))) {
+ spin_lock_irqsave(&block_lock, flags);
+ for (bb = bigblocks; bb; bb = bb->next)
+ if (bb->pages == block) {
+ spin_unlock_irqrestore(&slob_lock, flags);
+ return PAGE_SIZE << bb->order;
+ }
+ spin_unlock_irqrestore(&block_lock, flags);
+ }
+
+ return ((slob_t *)block - 1)->units * SLOB_UNIT;
+}
+
+struct kmem_cache_s {
+ unsigned int size, align;
+ const char *name;
+ void (*ctor)(void *, kmem_cache_t *, unsigned long);
+ void (*dtor)(void *, kmem_cache_t *, unsigned long);
+};
+
+kmem_cache_t *kmem_cache_create(const char *name, size_t size, size_t align,
+ unsigned long flags,
+ void (*ctor)(void*, kmem_cache_t *, unsigned long),
+ void (*dtor)(void*, kmem_cache_t *, unsigned long))
+{
+ kmem_cache_t *c;
+
+ c = slob_alloc(sizeof(kmem_cache_t), flags, 0);
+
+ if (c) {
+ c->name = name;
+ c->size = size;
+ c->ctor = ctor;
+ c->dtor = dtor;
+ /* ignore alignment unless it's forced */
+ c->align = (flags & SLAB_MUST_HWCACHE_ALIGN) ? SLOB_ALIGN : 0;
+ if (c->align < align)
+ c->align = align;
+ }
+
+ return c;
+}
+EXPORT_SYMBOL(kmem_cache_create);
+
+int kmem_cache_destroy(kmem_cache_t *c)
+{
+ slob_free(c, sizeof(kmem_cache_t));
+ return 0;
+}
+EXPORT_SYMBOL(kmem_cache_destroy);
+
+void *kmem_cache_alloc(kmem_cache_t *c, gfp_t flags)
+{
+ void *b;
+
+ if (c->size < PAGE_SIZE)
+ b = slob_alloc(c->size, flags, c->align);
+ else
+ b = (void *)__get_free_pages(flags, find_order(c->size));
+
+ if (c->ctor)
+ c->ctor(b, c, SLAB_CTOR_CONSTRUCTOR);
+
+ return b;
+}
+EXPORT_SYMBOL(kmem_cache_alloc);
+
+void kmem_cache_free(kmem_cache_t *c, void *b)
+{
+ if (c->dtor)
+ c->dtor(b, c, 0);
+
+ if (c->size < PAGE_SIZE)
+ slob_free(b, c->size);
+ else
+ free_pages((unsigned long)b, find_order(c->size));
+}
+EXPORT_SYMBOL(kmem_cache_free);
+
+unsigned int kmem_cache_size(kmem_cache_t *c)
+{
+ return c->size;
+}
+EXPORT_SYMBOL(kmem_cache_size);
+
+const char *kmem_cache_name(kmem_cache_t *c)
+{
+ return c->name;
+}
+EXPORT_SYMBOL(kmem_cache_name);
+
+static struct timer_list slob_timer = TIMER_INITIALIZER(
+ (void (*)(unsigned long))kmem_cache_init, 0, 0);
+
+void kmem_cache_init(void)
+{
+ void *p = slob_alloc(PAGE_SIZE, 0, PAGE_SIZE-1);
+
+ if (p)
+ free_page((unsigned int)p);
+
+ mod_timer(&slob_timer, jiffies + HZ);
+}
+
+atomic_t slab_reclaim_pages = ATOMIC_INIT(0);
+EXPORT_SYMBOL(slab_reclaim_pages);
+
+#ifdef CONFIG_SMP
+
+void *__alloc_percpu(size_t size, size_t align)
+{
+ int i;
+ struct percpu_data *pdata = kmalloc(sizeof (*pdata), GFP_KERNEL);
+
+ if (!pdata)
+ return NULL;
+
+ for (i = 0; i < NR_CPUS; i++) {
+ if (!cpu_possible(i))
+ continue;
+ pdata->ptrs[i] = kmalloc(size, GFP_KERNEL);
+ if (!pdata->ptrs[i])
+ goto unwind_oom;
+ memset(pdata->ptrs[i], 0, size);
+ }
+
+ /* Catch derefs w/o wrappers */
+ return (void *) (~(unsigned long) pdata);
+
+unwind_oom:
+ while (--i >= 0) {
+ if (!cpu_possible(i))
+ continue;
+ kfree(pdata->ptrs[i]);
+ }
+ kfree(pdata);
+ return NULL;
+}
+EXPORT_SYMBOL(__alloc_percpu);
+
+void
+free_percpu(const void *objp)
+{
+ int i;
+ struct percpu_data *p = (struct percpu_data *) (~(unsigned long) objp);
+
+ for (i = 0; i < NR_CPUS; i++) {
+ if (!cpu_possible(i))
+ continue;
+ kfree(p->ptrs[i]);
+ }
+ kfree(p);
+}
+EXPORT_SYMBOL(free_percpu);
+
+#endif
Index: 2.6.14-slob/mm/Makefile
===================================================================
--- 2.6.14-slob.orig/mm/Makefile 2005-11-03 14:48:17.000000000 -0800
+++ 2.6.14-slob/mm/Makefile 2005-11-03 14:54:22.000000000 -0800
@@ -9,7 +9,7 @@ mmu-$(CONFIG_MMU) := fremap.o highmem.o

obj-y := bootmem.o filemap.o mempool.o oom_kill.o fadvise.o \
page_alloc.o page-writeback.o pdflush.o \
- readahead.o slab.o swap.o truncate.o vmscan.o \
+ readahead.o swap.o truncate.o vmscan.o \
prio_tree.o util.o $(mmu-y)

obj-$(CONFIG_SWAP) += page_io.o swap_state.o swapfile.o thrash.o
@@ -18,5 +18,7 @@ obj-$(CONFIG_NUMA) += mempolicy.o
obj-$(CONFIG_SPARSEMEM) += sparse.o
obj-$(CONFIG_SHMEM) += shmem.o
obj-$(CONFIG_TINY_SHMEM) += tiny-shmem.o
+obj-$(CONFIG_SLOB) += slob.o
+obj-$(CONFIG_SLAB) += slab.o
obj-$(CONFIG_MEMORY_HOTPLUG) += memory_hotplug.o
obj-$(CONFIG_FS_XIP) += filemap_xip.o
Index: 2.6.14-slob/include/linux/slab.h
===================================================================
--- 2.6.14-slob.orig/include/linux/slab.h 2005-11-03 14:40:31.000000000 -0800
+++ 2.6.14-slob/include/linux/slab.h 2005-11-03 14:53:53.000000000 -0800
@@ -53,6 +53,8 @@ typedef struct kmem_cache_s kmem_cache_t
#define SLAB_CTOR_ATOMIC 0x002UL /* tell constructor it can't sleep */
#define SLAB_CTOR_VERIFY 0x004UL /* tell constructor it's a verify call */

+#ifndef CONFIG_SLOB
+
/* prototypes */
extern void __init kmem_cache_init(void);

@@ -134,6 +136,38 @@ static inline void *kmalloc_node(size_t
extern int FASTCALL(kmem_cache_reap(int));
extern int FASTCALL(kmem_ptr_validate(kmem_cache_t *cachep, void *ptr));

+#else /* CONFIG_SLOB */
+
+/* SLOB allocator routines */
+
+void kmem_cache_init(void);
+kmem_cache_t *kmem_find_general_cachep(size_t, gfp_t gfpflags);
+kmem_cache_t *kmem_cache_create(const char *c, size_t, size_t, unsigned long,
+ void (*)(void *, kmem_cache_t *, unsigned long),
+ void (*)(void *, kmem_cache_t *, unsigned long));
+int kmem_cache_destroy(kmem_cache_t *c);
+void *kmem_cache_alloc(kmem_cache_t *c, gfp_t flags);
+void kmem_cache_free(kmem_cache_t *c, void *b);
+const char *kmem_cache_name(kmem_cache_t *);
+void *kmalloc(size_t size, gfp_t flags);
+void *kzalloc(size_t size, gfp_t flags);
+void kfree(const void *m);
+unsigned int ksize(const void *m);
+unsigned int kmem_cache_size(kmem_cache_t *c);
+
+static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
+{
+ return kzalloc(n * size, flags);
+}
+
+#define kmem_cache_shrink(d) (0)
+#define kmem_cache_reap(a)
+#define kmem_ptr_validate(a, b) (0)
+#define kmem_cache_alloc_node(c, f, n) kmem_cache_alloc(c, f)
+#define kmalloc_node(s, f, n) kmalloc(s, f)
+
+#endif /* CONFIG_SLOB */
+
/* System wide caches */
extern kmem_cache_t *vm_area_cachep;
extern kmem_cache_t *names_cachep;
Index: 2.6.14-slob/init/Kconfig
===================================================================
--- 2.6.14-slob.orig/init/Kconfig 2005-11-03 14:40:31.000000000 -0800
+++ 2.6.14-slob/init/Kconfig 2005-11-03 14:53:53.000000000 -0800
@@ -398,6 +398,15 @@ config CC_ALIGN_JUMPS
no dummy operations need be executed.
Zero means use compiler's default.

+config SLAB
+ default y
+ bool "Use full SLAB allocator" if EMBEDDED
+ help
+ Disabling this replaces the advanced SLAB allocator and
+ kmalloc support with the drastically simpler SLOB allocator.
+ SLOB is more space efficient but does not scale well and is
+ more susceptible to fragmentation.
+
endmenu # General setup

config TINY_SHMEM
@@ -409,6 +418,10 @@ config BASE_SMALL
default 0 if BASE_FULL
default 1 if !BASE_FULL

+config SLOB
+ default !SLAB
+ bool
+
menu "Loadable module support"

config MODULES
Index: 2.6.14-slob/fs/proc/proc_misc.c
===================================================================
--- 2.6.14-slob.orig/fs/proc/proc_misc.c 2005-11-03 14:40:31.000000000 -0800
+++ 2.6.14-slob/fs/proc/proc_misc.c 2005-11-03 14:53:53.000000000 -0800
@@ -323,6 +323,7 @@ static struct file_operations proc_modul
};
#endif

+#ifdef CONFIG_SLAB
extern struct seq_operations slabinfo_op;
extern ssize_t slabinfo_write(struct file *, const char __user *, size_t, loff_t *);
static int slabinfo_open(struct inode *inode, struct file *file)
@@ -336,6 +337,7 @@ static struct file_operations proc_slabi
.llseek = seq_lseek,
.release = seq_release,
};
+#endif

static int show_stat(struct seq_file *p, void *v)
{
@@ -600,7 +602,9 @@ void __init proc_misc_init(void)
create_seq_entry("partitions", 0, &proc_partitions_operations);
create_seq_entry("stat", 0, &proc_stat_operations);
create_seq_entry("interrupts", 0, &proc_interrupts_operations);
+#ifdef CONFIG_SLAB
create_seq_entry("slabinfo",S_IWUSR|S_IRUGO,&proc_slabinfo_operations);
+#endif
create_seq_entry("buddyinfo",S_IRUGO, &fragmentation_file_operations);
create_seq_entry("vmstat",S_IRUGO, &proc_vmstat_file_operations);
create_seq_entry("zoneinfo",S_IRUGO, &proc_zoneinfo_file_operations);

2005-11-04 05:14:06

by Andrew Morton

[permalink] [raw]
Subject: Re: [PATCH 1/2] slob: introduce mm/util.c for shared functions

Matt Mackall <[email protected]> wrote:
>
> Add mm/util.c for functions common between SLAB and SLOB.

We should probably add a ppc32-developers-are-weenies warning to string.c

2005-11-04 06:30:11

by Matt Mackall

[permalink] [raw]
Subject: Re: [PATCH 1/2] slob: introduce mm/util.c for shared functions

On Thu, Nov 03, 2005 at 09:13:57PM -0800, Andrew Morton wrote:
> Matt Mackall <[email protected]> wrote:
> >
> > Add mm/util.c for functions common between SLAB and SLOB.
>
> We should probably add a ppc32-developers-are-weenies warning to string.c

Well, yes. But I decided not to do that now because I ended up wanting
to create mm/util.c anyway for kzalloc. I suspect we'll see other
helper functions like kzalloc and kstrdup down the road.

Also, I haven't investigated the PPC entanglements too closely, but
converting it to use my cleaned up lib/inflate.c might reduce its
dependence on lib/string.c

--
Mathematics is the supreme nostalgia of our time.

2005-11-04 08:20:49

by Pekka Enberg

[permalink] [raw]
Subject: Re: [PATCH 1/2] slob: introduce mm/util.c for shared functions

On 11/4/05, Matt Mackall <[email protected]> wrote:
> Well, yes. But I decided not to do that now because I ended up wanting
> to create mm/util.c anyway for kzalloc. I suspect we'll see other
> helper functions like kzalloc and kstrdup down the road.

I prefer this as well. kstrdup() is _not_ a string operation but a
special purpose memory allocator just like kzalloc() and kcalloc().

Pekka

2005-11-04 15:47:05

by Paulo Marques

[permalink] [raw]
Subject: Re: [PATCH 1/2] slob: introduce mm/util.c for shared functions

Pekka Enberg wrote:
> On 11/4/05, Matt Mackall <[email protected]> wrote:
>
>>Well, yes. But I decided not to do that now because I ended up wanting
>>to create mm/util.c anyway for kzalloc. I suspect we'll see other
>>helper functions like kzalloc and kstrdup down the road.
>
> I prefer this as well. kstrdup() is _not_ a string operation but a
> special purpose memory allocator just like kzalloc() and kcalloc().

It is even worse than just personal preference.

Having kstrdup in lib/string was actually tried first, but there are
archs that use lib/string for their boot code.

This boot code has no kmalloc available, so the dependency of kstrdup on
kmalloc breaks the build for them if kstrdup is moved to lib/string.

--
Paulo Marques - http://www.grupopie.com

The rule is perfect: in all matters of opinion our
adversaries are insane.
Mark Twain

2005-11-07 20:29:26

by Tom Rini

[permalink] [raw]
Subject: Re: [PATCH 1/2] slob: introduce mm/util.c for shared functions

On Thu, Nov 03, 2005 at 10:24:55PM -0800, Matt Mackall wrote:
> On Thu, Nov 03, 2005 at 09:13:57PM -0800, Andrew Morton wrote:
> > Matt Mackall <[email protected]> wrote:
> > >
> > > Add mm/util.c for functions common between SLAB and SLOB.
> >
> > We should probably add a ppc32-developers-are-weenies warning to string.c
>
> Well, yes. But I decided not to do that now because I ended up wanting
> to create mm/util.c anyway for kzalloc. I suspect we'll see other
> helper functions like kzalloc and kstrdup down the road.
>
> Also, I haven't investigated the PPC entanglements too closely, but
> converting it to use my cleaned up lib/inflate.c might reduce its
> dependence on lib/string.c

That's on my list of things to go and poke. But I don't recall us
depending on lib/string.c nowadays (but an occasional reimpl to match
declaration), just lib/zlib_inflate/

--
Tom Rini
http://gate.crashing.org/~trini/