Hi,
I am having a problem with memory leaking on a patched kernel. In order
to pinpoint the leak, I would like to try to trace the allocation points
for the memory.
I have found some vague references to patches that allow the user to
dump the caller address for slab allocations, but I cannot find the
patch itself.
Can anybody please point me in the right direction - either for that
patch, or any other way to track down leaking slabs?
Thank you,
Justin Schoeman
Justin Schoeman <[email protected]> wrote:
>
> I am having a problem with memory leaking on a patched kernel. In order
> to pinpoint the leak, I would like to try to trace the allocation points
> for the memory.
>
> I have found some vague references to patches that allow the user to
> dump the caller address for slab allocations, but I cannot find the
> patch itself.
>
> Can anybody please point me in the right direction - either for that
> patch, or any other way to track down leaking slabs?
From: Manfred Spraul <[email protected]>
With the patch applied,
echo "size-4096 0 0 0" > /proc/slabinfo
walks the objects in the size-4096 slab, printing out the calling address
of whoever allocated that object.
It is for leak detection.
Signed-off-by: Andrew Morton <[email protected]>
---
25-akpm/mm/slab.c | 40 ++++++++++++++++++++++++++++++++++++++--
1 files changed, 38 insertions(+), 2 deletions(-)
diff -puN mm/slab.c~slab-leak-detector mm/slab.c
--- 25/mm/slab.c~slab-leak-detector 2005-02-15 21:06:44.000000000 -0800
+++ 25-akpm/mm/slab.c 2005-02-15 21:06:44.000000000 -0800
@@ -2116,6 +2116,15 @@ cache_alloc_debugcheck_after(kmem_cache_
*dbg_redzone1(cachep, objp) = RED_ACTIVE;
*dbg_redzone2(cachep, objp) = RED_ACTIVE;
}
+ {
+ int objnr;
+ struct slab *slabp;
+
+ slabp = GET_PAGE_SLAB(virt_to_page(objp));
+
+ objnr = (objp - slabp->s_mem) / cachep->objsize;
+ slab_bufctl(slabp)[objnr] = (unsigned long)caller;
+ }
objp += obj_dbghead(cachep);
if (cachep->ctor && cachep->flags & SLAB_POISON) {
unsigned long ctor_flags = SLAB_CTOR_CONSTRUCTOR;
@@ -2179,12 +2188,14 @@ static void free_block(kmem_cache_t *cac
objnr = (objp - slabp->s_mem) / cachep->objsize;
check_slabp(cachep, slabp);
#if DEBUG
+#if 0
if (slab_bufctl(slabp)[objnr] != BUFCTL_FREE) {
printk(KERN_ERR "slab: double free detected in cache '%s', objp %p.\n",
cachep->name, objp);
BUG();
}
#endif
+#endif
slab_bufctl(slabp)[objnr] = slabp->free;
slabp->free = objnr;
STATS_DEC_ACTIVE(cachep);
@@ -2998,6 +3009,29 @@ struct seq_operations slabinfo_op = {
.show = s_show,
};
+static void do_dump_slabp(kmem_cache_t *cachep)
+{
+#if DEBUG
+ struct list_head *q;
+
+ check_irq_on();
+ spin_lock_irq(&cachep->spinlock);
+ list_for_each(q,&cachep->lists.slabs_full) {
+ struct slab *slabp;
+ int i;
+ slabp = list_entry(q, struct slab, list);
+ for (i = 0; i < cachep->num; i++) {
+ unsigned long sym = slab_bufctl(slabp)[i];
+
+ printk("obj %p/%d: %p", slabp, i, (void *)sym);
+ print_symbol(" <%s>", sym);
+ printk("\n");
+ }
+ }
+ spin_unlock_irq(&cachep->spinlock);
+#endif
+}
+
#define MAX_SLABINFO_WRITE 128
/**
* slabinfo_write - Tuning for the slab allocator
@@ -3038,9 +3072,11 @@ ssize_t slabinfo_write(struct file *file
batchcount < 1 ||
batchcount > limit ||
shared < 0) {
- res = -EINVAL;
+ do_dump_slabp(cachep);
+ res = 0;
} else {
- res = do_tune_cpucache(cachep, limit, batchcount, shared);
+ res = do_tune_cpucache(cachep, limit,
+ batchcount, shared);
}
break;
}
_
> I am having a problem with memory leaking on a patched kernel. In order
> to pinpoint the leak, I would like to try to trace the allocation points
> for the memory.
>
> I have found some vague references to patches that allow the user to
> dump the caller address for slab allocations, but I cannot find the
> patch itself.
>
> Can anybody please point me in the right direction - either for that
> patch, or any other way to track down leaking slabs?
>
>From akpm:
Could you please use this patch? Make sure that you enable
CONFIG_FRAME_POINTER (might not be needed for __builtin_return_address(0),
but let's be sure). Also enable CONFIG_DEBUG_SLAB.
From: Manfred Spraul <[email protected]>
With the patch applied,
echo "size-4096 0 0 0" > /proc/slabinfo
walks the objects in the size-4096 slab, printing out the calling address
of whoever allocated that object.
It is for leak detection.
diff -puN mm/slab.c~slab-leak-detector mm/slab.c
--- 25/mm/slab.c~slab-leak-detector 2005-02-15 21:06:44.000000000 -0800
+++ 25-akpm/mm/slab.c 2005-02-15 21:06:44.000000000 -0800
@@ -2116,6 +2116,15 @@ cache_alloc_debugcheck_after(kmem_cache_
*dbg_redzone1(cachep, objp) = RED_ACTIVE;
*dbg_redzone2(cachep, objp) = RED_ACTIVE;
}
+ {
+ int objnr;
+ struct slab *slabp;
+
+ slabp = GET_PAGE_SLAB(virt_to_page(objp));
+
+ objnr = (objp - slabp->s_mem) / cachep->objsize;
+ slab_bufctl(slabp)[objnr] = (unsigned long)caller;
+ }
objp += obj_dbghead(cachep);
if (cachep->ctor && cachep->flags & SLAB_POISON) {
unsigned long ctor_flags = SLAB_CTOR_CONSTRUCTOR;
@@ -2179,12 +2188,14 @@ static void free_block(kmem_cache_t *cac
objnr = (objp - slabp->s_mem) / cachep->objsize;
check_slabp(cachep, slabp);
#if DEBUG
+#if 0
if (slab_bufctl(slabp)[objnr] != BUFCTL_FREE) {
printk(KERN_ERR "slab: double free detected in cache '%s', objp %p.\n",
cachep->name, objp);
BUG();
}
#endif
+#endif
slab_bufctl(slabp)[objnr] = slabp->free;
slabp->free = objnr;
STATS_DEC_ACTIVE(cachep);
@@ -2998,6 +3009,29 @@ struct seq_operations slabinfo_op = {
.show = s_show,
};
+static void do_dump_slabp(kmem_cache_t *cachep)
+{
+#if DEBUG
+ struct list_head *q;
+
+ check_irq_on();
+ spin_lock_irq(&cachep->spinlock);
+ list_for_each(q,&cachep->lists.slabs_full) {
+ struct slab *slabp;
+ int i;
+ slabp = list_entry(q, struct slab, list);
+ for (i = 0; i < cachep->num; i++) {
+ unsigned long sym = slab_bufctl(slabp)[i];
+
+ printk("obj %p/%d: %p", slabp, i, (void *)sym);
+ print_symbol(" <%s>", sym);
+ printk("\n");
+ }
+ }
+ spin_unlock_irq(&cachep->spinlock);
+#endif
+}
+
#define MAX_SLABINFO_WRITE 128
/**
* slabinfo_write - Tuning for the slab allocator
@@ -3038,9 +3072,11 @@ ssize_t slabinfo_write(struct file *file
batchcount < 1 ||
batchcount > limit ||
shared < 0) {
- res = -EINVAL;
+ do_dump_slabp(cachep);
+ res = 0;
} else {
- res = do_tune_cpucache(cachep, limit, batchcount, shared);
+ res = do_tune_cpucache(cachep, limit,
+ batchcount, shared);
}
break;
}
_
Andrew Morton <[email protected]> writes:
> + slab_bufctl(slabp)[objnr] = (unsigned long)caller;
Umm... this patch looks strange..
slab_bufctl() returns "kmem_bufctl_t *", but kmem_bufctl_t is
"unsigned short".
I guess that this debug patch was broken by something else...
--
OGAWA Hirofumi <[email protected]>
OGAWA Hirofumi <[email protected]> wrote:
>
> Andrew Morton <[email protected]> writes:
>
> > + slab_bufctl(slabp)[objnr] = (unsigned long)caller;
>
> Umm... this patch looks strange..
>
> slab_bufctl() returns "kmem_bufctl_t *", but kmem_bufctl_t is
> "unsigned short".
Good point. This seems to work.
From: Manfred Spraul <[email protected]>
With the patch applied,
echo "size-4096 0 0 0" > /proc/slabinfo
walks the objects in the size-4096 slab, printing out the calling address
of whoever allocated that object.
It is for leak detection.
Signed-off-by: Andrew Morton <[email protected]>
---
25-akpm/include/asm-alpha/types.h | 2 -
25-akpm/include/asm-arm/types.h | 2 -
25-akpm/include/asm-arm26/types.h | 2 -
25-akpm/include/asm-cris/types.h | 2 -
25-akpm/include/asm-frv/types.h | 2 -
25-akpm/include/asm-h8300/types.h | 2 -
25-akpm/include/asm-i386/types.h | 2 -
25-akpm/include/asm-ia64/types.h | 2 -
25-akpm/include/asm-m32r/types.h | 2 -
25-akpm/include/asm-m68k/types.h | 2 -
25-akpm/include/asm-mips/types.h | 2 -
25-akpm/include/asm-parisc/types.h | 2 -
25-akpm/include/asm-ppc/types.h | 2 -
25-akpm/include/asm-ppc64/types.h | 2 -
25-akpm/include/asm-s390/types.h | 2 -
25-akpm/include/asm-sh/types.h | 2 -
25-akpm/include/asm-sh64/types.h | 2 -
25-akpm/include/asm-sparc/types.h | 2 -
25-akpm/include/asm-sparc64/types.h | 2 -
25-akpm/include/asm-v850/types.h | 2 -
25-akpm/include/asm-x86_64/types.h | 2 -
25-akpm/mm/slab.c | 40 ++++++++++++++++++++++++++++++++++--
22 files changed, 59 insertions(+), 23 deletions(-)
diff -puN include/asm-alpha/types.h~slab-leak-detector include/asm-alpha/types.h
--- 25/include/asm-alpha/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-alpha/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -56,7 +56,7 @@ typedef unsigned long u64;
typedef u64 dma_addr_t;
typedef u64 dma64_addr_t;
-typedef unsigned short kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
#endif /* __KERNEL__ */
diff -puN include/asm-arm26/types.h~slab-leak-detector include/asm-arm26/types.h
--- 25/include/asm-arm26/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-arm26/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -52,7 +52,7 @@ typedef unsigned long long u64;
typedef u32 dma_addr_t;
typedef u32 dma64_addr_t;
-typedef unsigned int kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
diff -puN include/asm-arm/types.h~slab-leak-detector include/asm-arm/types.h
--- 25/include/asm-arm/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-arm/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -52,7 +52,7 @@ typedef unsigned long long u64;
typedef u32 dma_addr_t;
typedef u32 dma64_addr_t;
-typedef unsigned int kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
diff -puN include/asm-cris/types.h~slab-leak-detector include/asm-cris/types.h
--- 25/include/asm-cris/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-cris/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -52,7 +52,7 @@ typedef unsigned long long u64;
typedef u32 dma_addr_t;
typedef u32 dma64_addr_t;
-typedef unsigned int kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
diff -puN include/asm-frv/types.h~slab-leak-detector include/asm-frv/types.h
--- 25/include/asm-frv/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-frv/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -65,7 +65,7 @@ typedef u64 u_quad_t;
typedef u32 dma_addr_t;
-typedef unsigned short kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
diff -puN include/asm-h8300/types.h~slab-leak-detector include/asm-h8300/types.h
--- 25/include/asm-h8300/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-h8300/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -58,7 +58,7 @@ typedef u32 dma_addr_t;
#define HAVE_SECTOR_T
typedef u64 sector_t;
-typedef unsigned int kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __KERNEL__ */
diff -puN include/asm-i386/types.h~slab-leak-detector include/asm-i386/types.h
--- 25/include/asm-i386/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-i386/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -63,7 +63,7 @@ typedef u64 sector_t;
#define HAVE_SECTOR_T
#endif
-typedef unsigned short kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
diff -puN include/asm-ia64/types.h~slab-leak-detector include/asm-ia64/types.h
--- 25/include/asm-ia64/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-ia64/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -67,7 +67,7 @@ typedef __u64 u64;
typedef u64 dma_addr_t;
-typedef unsigned short kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
# endif /* __KERNEL__ */
#endif /* !__ASSEMBLY__ */
diff -puN include/asm-m32r/types.h~slab-leak-detector include/asm-m32r/types.h
--- 25/include/asm-m32r/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-m32r/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -55,7 +55,7 @@ typedef unsigned long long u64;
typedef u32 dma_addr_t;
typedef u64 dma64_addr_t;
-typedef unsigned short kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
diff -puN include/asm-m68k/types.h~slab-leak-detector include/asm-m68k/types.h
--- 25/include/asm-m68k/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-m68k/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -60,7 +60,7 @@ typedef unsigned long long u64;
typedef u32 dma_addr_t;
typedef u32 dma64_addr_t;
-typedef unsigned short kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
diff -puN include/asm-mips/types.h~slab-leak-detector include/asm-mips/types.h
--- 25/include/asm-mips/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-mips/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -99,7 +99,7 @@ typedef u64 sector_t;
#define HAVE_SECTOR_T
#endif
-typedef unsigned short kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
diff -puN include/asm-parisc/types.h~slab-leak-detector include/asm-parisc/types.h
--- 25/include/asm-parisc/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-parisc/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -56,7 +56,7 @@ typedef unsigned long long u64;
typedef u32 dma_addr_t;
typedef u64 dma64_addr_t;
-typedef unsigned int kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
diff -puN include/asm-ppc64/types.h~slab-leak-detector include/asm-ppc64/types.h
--- 25/include/asm-ppc64/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-ppc64/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -72,7 +72,7 @@ typedef struct {
unsigned long env;
} func_descr_t;
-typedef unsigned int kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
#endif /* __KERNEL__ */
diff -puN include/asm-ppc/types.h~slab-leak-detector include/asm-ppc/types.h
--- 25/include/asm-ppc/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-ppc/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -62,7 +62,7 @@ typedef u64 sector_t;
#define HAVE_SECTOR_T
#endif
-typedef unsigned int kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
diff -puN include/asm-s390/types.h~slab-leak-detector include/asm-s390/types.h
--- 25/include/asm-s390/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-s390/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -79,7 +79,7 @@ typedef unsigned long u64;
typedef u32 dma_addr_t;
-typedef unsigned int kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#ifndef __s390x__
typedef union {
diff -puN include/asm-sh64/types.h~slab-leak-detector include/asm-sh64/types.h
--- 25/include/asm-sh64/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-sh64/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -65,7 +65,7 @@ typedef u32 dma_addr_t;
#endif
typedef u64 dma64_addr_t;
-typedef unsigned int kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
diff -puN include/asm-sh/types.h~slab-leak-detector include/asm-sh/types.h
--- 25/include/asm-sh/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-sh/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -58,7 +58,7 @@ typedef u64 sector_t;
#define HAVE_SECTOR_T
#endif
-typedef unsigned int kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
diff -puN include/asm-sparc64/types.h~slab-leak-detector include/asm-sparc64/types.h
--- 25/include/asm-sparc64/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-sparc64/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -56,7 +56,7 @@ typedef unsigned long u64;
typedef u32 dma_addr_t;
typedef u64 dma64_addr_t;
-typedef unsigned short kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
diff -puN include/asm-sparc/types.h~slab-leak-detector include/asm-sparc/types.h
--- 25/include/asm-sparc/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-sparc/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -54,7 +54,7 @@ typedef unsigned long long u64;
typedef u32 dma_addr_t;
typedef u32 dma64_addr_t;
-typedef unsigned short kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
diff -puN include/asm-v850/types.h~slab-leak-detector include/asm-v850/types.h
--- 25/include/asm-v850/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-v850/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -59,7 +59,7 @@ typedef unsigned long long u64;
typedef u32 dma_addr_t;
-typedef unsigned int kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* !__ASSEMBLY__ */
diff -puN include/asm-x86_64/types.h~slab-leak-detector include/asm-x86_64/types.h
--- 25/include/asm-x86_64/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-x86_64/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -51,7 +51,7 @@ typedef u64 dma_addr_t;
typedef u64 sector_t;
#define HAVE_SECTOR_T
-typedef unsigned short kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
diff -puN mm/slab.c~slab-leak-detector mm/slab.c
--- 25/mm/slab.c~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/mm/slab.c 2005-03-02 08:30:59.000000000 -0800
@@ -2116,6 +2116,15 @@ cache_alloc_debugcheck_after(kmem_cache_
*dbg_redzone1(cachep, objp) = RED_ACTIVE;
*dbg_redzone2(cachep, objp) = RED_ACTIVE;
}
+ {
+ int objnr;
+ struct slab *slabp;
+
+ slabp = GET_PAGE_SLAB(virt_to_page(objp));
+
+ objnr = (objp - slabp->s_mem) / cachep->objsize;
+ slab_bufctl(slabp)[objnr] = (unsigned long)caller;
+ }
objp += obj_dbghead(cachep);
if (cachep->ctor && cachep->flags & SLAB_POISON) {
unsigned long ctor_flags = SLAB_CTOR_CONSTRUCTOR;
@@ -2179,12 +2188,14 @@ static void free_block(kmem_cache_t *cac
objnr = (objp - slabp->s_mem) / cachep->objsize;
check_slabp(cachep, slabp);
#if DEBUG
+#if 0
if (slab_bufctl(slabp)[objnr] != BUFCTL_FREE) {
printk(KERN_ERR "slab: double free detected in cache '%s', objp %p.\n",
cachep->name, objp);
BUG();
}
#endif
+#endif
slab_bufctl(slabp)[objnr] = slabp->free;
slabp->free = objnr;
STATS_DEC_ACTIVE(cachep);
@@ -2998,6 +3009,29 @@ struct seq_operations slabinfo_op = {
.show = s_show,
};
+static void do_dump_slabp(kmem_cache_t *cachep)
+{
+#if DEBUG
+ struct list_head *q;
+
+ check_irq_on();
+ spin_lock_irq(&cachep->spinlock);
+ list_for_each(q,&cachep->lists.slabs_full) {
+ struct slab *slabp;
+ int i;
+ slabp = list_entry(q, struct slab, list);
+ for (i = 0; i < cachep->num; i++) {
+ unsigned long sym = slab_bufctl(slabp)[i];
+
+ printk("obj %p/%d: %p", slabp, i, (void *)sym);
+ print_symbol(" <%s>", sym);
+ printk("\n");
+ }
+ }
+ spin_unlock_irq(&cachep->spinlock);
+#endif
+}
+
#define MAX_SLABINFO_WRITE 128
/**
* slabinfo_write - Tuning for the slab allocator
@@ -3038,9 +3072,11 @@ ssize_t slabinfo_write(struct file *file
batchcount < 1 ||
batchcount > limit ||
shared < 0) {
- res = -EINVAL;
+ do_dump_slabp(cachep);
+ res = 0;
} else {
- res = do_tune_cpucache(cachep, limit, batchcount, shared);
+ res = do_tune_cpucache(cachep, limit,
+ batchcount, shared);
}
break;
}
_
--- 2.6/mm/slab.c 2005-03-02 20:44:47.738737171 +0100
+++ build-2.6/mm/slab.c 2005-03-02 20:44:15.290618759 +0100
@@ -2645,18 +2642,10 @@
red1 = *dbg_redzone1(cachep, objp);
red2 = *dbg_redzone2(cachep, objp);
- /* simplest case: marked as inactive */
- if (red1 == RED_INACTIVE && red2 == RED_INACTIVE)
- continue;
-
- /* tricky case: if the bufctl value is BUFCTL_ALLOC, then
- * the object is either allocated or somewhere in a cpu
- * cache. The cpu caches are lockless and there might be
- * a concurrent alloc/free call, thus we must accept random
- * combinations of RED_ACTIVE and _INACTIVE
+ /* leak detection stores the caller address in the bufctl,
+ * thus random combinations of active and inactive are ok
*/
- if (slab_bufctl(slabp)[i] == BUFCTL_ALLOC &&
- (red1 == RED_INACTIVE || red1 == RED_ACTIVE) &&
+ if ((red1 == RED_INACTIVE || red1 == RED_ACTIVE) &&
(red2 == RED_INACTIVE || red2 == RED_ACTIVE))
continue;
OK - I have the patch working now, but there seems to be a flaw in the
address reporting. When I look up the reported address in
/proc/kallsyms, then look in the objdump of the module, the reported
adress _does_not_ point to a call.
Am I missing something simple here?
Justin
Andrew Morton wrote:
> Justin Schoeman <[email protected]> wrote:
>
>>I am having a problem with memory leaking on a patched kernel. In order
>> to pinpoint the leak, I would like to try to trace the allocation points
>> for the memory.
>>
>> I have found some vague references to patches that allow the user to
>> dump the caller address for slab allocations, but I cannot find the
>> patch itself.
>>
>> Can anybody please point me in the right direction - either for that
>> patch, or any other way to track down leaking slabs?
>
>
>
> From: Manfred Spraul <[email protected]>
>
> With the patch applied,
>
> echo "size-4096 0 0 0" > /proc/slabinfo
>
> walks the objects in the size-4096 slab, printing out the calling address
> of whoever allocated that object.
>
> It is for leak detection.
...
Justin Schoeman <[email protected]> wrote:
>
> OK - I have the patch working now, but there seems to be a flaw in the
> address reporting. When I look up the reported address in
> /proc/kallsyms, then look in the objdump of the module, the reported
> adress _does_not_ point to a call.
>
> Am I missing something simple here?
Use the latest version of the patch (below). Link the module into the
kernel. Enable CONFIG_KALLSYMS.
--- 25/include/asm-alpha/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-alpha/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -56,7 +56,7 @@ typedef unsigned long u64;
typedef u64 dma_addr_t;
typedef u64 dma64_addr_t;
-typedef unsigned short kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
#endif /* __KERNEL__ */
diff -puN include/asm-arm26/types.h~slab-leak-detector include/asm-arm26/types.h
--- 25/include/asm-arm26/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-arm26/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -52,7 +52,7 @@ typedef unsigned long long u64;
typedef u32 dma_addr_t;
typedef u32 dma64_addr_t;
-typedef unsigned int kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
diff -puN include/asm-arm/types.h~slab-leak-detector include/asm-arm/types.h
--- 25/include/asm-arm/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-arm/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -52,7 +52,7 @@ typedef unsigned long long u64;
typedef u32 dma_addr_t;
typedef u32 dma64_addr_t;
-typedef unsigned int kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
diff -puN include/asm-cris/types.h~slab-leak-detector include/asm-cris/types.h
--- 25/include/asm-cris/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-cris/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -52,7 +52,7 @@ typedef unsigned long long u64;
typedef u32 dma_addr_t;
typedef u32 dma64_addr_t;
-typedef unsigned int kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
diff -puN include/asm-frv/types.h~slab-leak-detector include/asm-frv/types.h
--- 25/include/asm-frv/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-frv/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -65,7 +65,7 @@ typedef u64 u_quad_t;
typedef u32 dma_addr_t;
-typedef unsigned short kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
diff -puN include/asm-h8300/types.h~slab-leak-detector include/asm-h8300/types.h
--- 25/include/asm-h8300/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-h8300/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -58,7 +58,7 @@ typedef u32 dma_addr_t;
#define HAVE_SECTOR_T
typedef u64 sector_t;
-typedef unsigned int kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __KERNEL__ */
diff -puN include/asm-i386/types.h~slab-leak-detector include/asm-i386/types.h
--- 25/include/asm-i386/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-i386/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -63,7 +63,7 @@ typedef u64 sector_t;
#define HAVE_SECTOR_T
#endif
-typedef unsigned short kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
diff -puN include/asm-ia64/types.h~slab-leak-detector include/asm-ia64/types.h
--- 25/include/asm-ia64/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-ia64/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -67,7 +67,7 @@ typedef __u64 u64;
typedef u64 dma_addr_t;
-typedef unsigned short kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
# endif /* __KERNEL__ */
#endif /* !__ASSEMBLY__ */
diff -puN include/asm-m32r/types.h~slab-leak-detector include/asm-m32r/types.h
--- 25/include/asm-m32r/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-m32r/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -55,7 +55,7 @@ typedef unsigned long long u64;
typedef u32 dma_addr_t;
typedef u64 dma64_addr_t;
-typedef unsigned short kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
diff -puN include/asm-m68k/types.h~slab-leak-detector include/asm-m68k/types.h
--- 25/include/asm-m68k/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-m68k/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -60,7 +60,7 @@ typedef unsigned long long u64;
typedef u32 dma_addr_t;
typedef u32 dma64_addr_t;
-typedef unsigned short kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
diff -puN include/asm-mips/types.h~slab-leak-detector include/asm-mips/types.h
--- 25/include/asm-mips/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-mips/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -99,7 +99,7 @@ typedef u64 sector_t;
#define HAVE_SECTOR_T
#endif
-typedef unsigned short kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
diff -puN include/asm-parisc/types.h~slab-leak-detector include/asm-parisc/types.h
--- 25/include/asm-parisc/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-parisc/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -56,7 +56,7 @@ typedef unsigned long long u64;
typedef u32 dma_addr_t;
typedef u64 dma64_addr_t;
-typedef unsigned int kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
diff -puN include/asm-ppc64/types.h~slab-leak-detector include/asm-ppc64/types.h
--- 25/include/asm-ppc64/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-ppc64/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -72,7 +72,7 @@ typedef struct {
unsigned long env;
} func_descr_t;
-typedef unsigned int kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
#endif /* __KERNEL__ */
diff -puN include/asm-ppc/types.h~slab-leak-detector include/asm-ppc/types.h
--- 25/include/asm-ppc/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-ppc/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -62,7 +62,7 @@ typedef u64 sector_t;
#define HAVE_SECTOR_T
#endif
-typedef unsigned int kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
diff -puN include/asm-s390/types.h~slab-leak-detector include/asm-s390/types.h
--- 25/include/asm-s390/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-s390/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -79,7 +79,7 @@ typedef unsigned long u64;
typedef u32 dma_addr_t;
-typedef unsigned int kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#ifndef __s390x__
typedef union {
diff -puN include/asm-sh64/types.h~slab-leak-detector include/asm-sh64/types.h
--- 25/include/asm-sh64/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-sh64/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -65,7 +65,7 @@ typedef u32 dma_addr_t;
#endif
typedef u64 dma64_addr_t;
-typedef unsigned int kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
diff -puN include/asm-sh/types.h~slab-leak-detector include/asm-sh/types.h
--- 25/include/asm-sh/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-sh/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -58,7 +58,7 @@ typedef u64 sector_t;
#define HAVE_SECTOR_T
#endif
-typedef unsigned int kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
diff -puN include/asm-sparc64/types.h~slab-leak-detector include/asm-sparc64/types.h
--- 25/include/asm-sparc64/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-sparc64/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -56,7 +56,7 @@ typedef unsigned long u64;
typedef u32 dma_addr_t;
typedef u64 dma64_addr_t;
-typedef unsigned short kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
diff -puN include/asm-sparc/types.h~slab-leak-detector include/asm-sparc/types.h
--- 25/include/asm-sparc/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-sparc/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -54,7 +54,7 @@ typedef unsigned long long u64;
typedef u32 dma_addr_t;
typedef u32 dma64_addr_t;
-typedef unsigned short kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
diff -puN include/asm-v850/types.h~slab-leak-detector include/asm-v850/types.h
--- 25/include/asm-v850/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-v850/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -59,7 +59,7 @@ typedef unsigned long long u64;
typedef u32 dma_addr_t;
-typedef unsigned int kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* !__ASSEMBLY__ */
diff -puN include/asm-x86_64/types.h~slab-leak-detector include/asm-x86_64/types.h
--- 25/include/asm-x86_64/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/include/asm-x86_64/types.h 2005-03-02 08:30:59.000000000 -0800
@@ -51,7 +51,7 @@ typedef u64 dma_addr_t;
typedef u64 sector_t;
#define HAVE_SECTOR_T
-typedef unsigned short kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#endif /* __ASSEMBLY__ */
diff -puN mm/slab.c~slab-leak-detector mm/slab.c
--- 25/mm/slab.c~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
+++ 25-akpm/mm/slab.c 2005-03-02 08:30:59.000000000 -0800
@@ -2116,6 +2116,15 @@ cache_alloc_debugcheck_after(kmem_cache_
*dbg_redzone1(cachep, objp) = RED_ACTIVE;
*dbg_redzone2(cachep, objp) = RED_ACTIVE;
}
+ {
+ int objnr;
+ struct slab *slabp;
+
+ slabp = GET_PAGE_SLAB(virt_to_page(objp));
+
+ objnr = (objp - slabp->s_mem) / cachep->objsize;
+ slab_bufctl(slabp)[objnr] = (unsigned long)caller;
+ }
objp += obj_dbghead(cachep);
if (cachep->ctor && cachep->flags & SLAB_POISON) {
unsigned long ctor_flags = SLAB_CTOR_CONSTRUCTOR;
@@ -2179,12 +2188,14 @@ static void free_block(kmem_cache_t *cac
objnr = (objp - slabp->s_mem) / cachep->objsize;
check_slabp(cachep, slabp);
#if DEBUG
+#if 0
if (slab_bufctl(slabp)[objnr] != BUFCTL_FREE) {
printk(KERN_ERR "slab: double free detected in cache '%s', objp %p.\n",
cachep->name, objp);
BUG();
}
#endif
+#endif
slab_bufctl(slabp)[objnr] = slabp->free;
slabp->free = objnr;
STATS_DEC_ACTIVE(cachep);
@@ -2998,6 +3009,29 @@ struct seq_operations slabinfo_op = {
.show = s_show,
};
+static void do_dump_slabp(kmem_cache_t *cachep)
+{
+#if DEBUG
+ struct list_head *q;
+
+ check_irq_on();
+ spin_lock_irq(&cachep->spinlock);
+ list_for_each(q,&cachep->lists.slabs_full) {
+ struct slab *slabp;
+ int i;
+ slabp = list_entry(q, struct slab, list);
+ for (i = 0; i < cachep->num; i++) {
+ unsigned long sym = slab_bufctl(slabp)[i];
+
+ printk("obj %p/%d: %p", slabp, i, (void *)sym);
+ print_symbol(" <%s>", sym);
+ printk("\n");
+ }
+ }
+ spin_unlock_irq(&cachep->spinlock);
+#endif
+}
+
#define MAX_SLABINFO_WRITE 128
/**
* slabinfo_write - Tuning for the slab allocator
@@ -3038,9 +3072,11 @@ ssize_t slabinfo_write(struct file *file
batchcount < 1 ||
batchcount > limit ||
shared < 0) {
- res = -EINVAL;
+ do_dump_slabp(cachep);
+ res = 0;
} else {
- res = do_tune_cpucache(cachep, limit, batchcount, shared);
+ res = do_tune_cpucache(cachep, limit,
+ batchcount, shared);
}
break;
}
_
Thanks everybody for your help. I have at least located the site of the
leak - now I just need to find out why the destructor is not being
called ;-).
Will the slab debugger make it into the kernel as a standard compile
time option? It is a _really_ usefull tool to have around.
Thanks again,
Justin
Andrew Morton wrote:
> Justin Schoeman <[email protected]> wrote:
>
>>OK - I have the patch working now, but there seems to be a flaw in the
>> address reporting. When I look up the reported address in
>> /proc/kallsyms, then look in the objdump of the module, the reported
>> adress _does_not_ point to a call.
>>
>> Am I missing something simple here?
>
>
> Use the latest version of the patch (below). Link the module into the
> kernel. Enable CONFIG_KALLSYMS.
>
> --- 25/include/asm-alpha/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
> +++ 25-akpm/include/asm-alpha/types.h 2005-03-02 08:30:59.000000000 -0800
> @@ -56,7 +56,7 @@ typedef unsigned long u64;
> typedef u64 dma_addr_t;
> typedef u64 dma64_addr_t;
>
> -typedef unsigned short kmem_bufctl_t;
> +typedef unsigned long kmem_bufctl_t;
>
> #endif /* __ASSEMBLY__ */
> #endif /* __KERNEL__ */
> diff -puN include/asm-arm26/types.h~slab-leak-detector include/asm-arm26/types.h
> --- 25/include/asm-arm26/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
> +++ 25-akpm/include/asm-arm26/types.h 2005-03-02 08:30:59.000000000 -0800
> @@ -52,7 +52,7 @@ typedef unsigned long long u64;
> typedef u32 dma_addr_t;
> typedef u32 dma64_addr_t;
>
> -typedef unsigned int kmem_bufctl_t;
> +typedef unsigned long kmem_bufctl_t;
>
> #endif /* __ASSEMBLY__ */
>
> diff -puN include/asm-arm/types.h~slab-leak-detector include/asm-arm/types.h
> --- 25/include/asm-arm/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
> +++ 25-akpm/include/asm-arm/types.h 2005-03-02 08:30:59.000000000 -0800
> @@ -52,7 +52,7 @@ typedef unsigned long long u64;
> typedef u32 dma_addr_t;
> typedef u32 dma64_addr_t;
>
> -typedef unsigned int kmem_bufctl_t;
> +typedef unsigned long kmem_bufctl_t;
>
> #endif /* __ASSEMBLY__ */
>
> diff -puN include/asm-cris/types.h~slab-leak-detector include/asm-cris/types.h
> --- 25/include/asm-cris/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
> +++ 25-akpm/include/asm-cris/types.h 2005-03-02 08:30:59.000000000 -0800
> @@ -52,7 +52,7 @@ typedef unsigned long long u64;
> typedef u32 dma_addr_t;
> typedef u32 dma64_addr_t;
>
> -typedef unsigned int kmem_bufctl_t;
> +typedef unsigned long kmem_bufctl_t;
>
> #endif /* __ASSEMBLY__ */
>
> diff -puN include/asm-frv/types.h~slab-leak-detector include/asm-frv/types.h
> --- 25/include/asm-frv/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
> +++ 25-akpm/include/asm-frv/types.h 2005-03-02 08:30:59.000000000 -0800
> @@ -65,7 +65,7 @@ typedef u64 u_quad_t;
>
> typedef u32 dma_addr_t;
>
> -typedef unsigned short kmem_bufctl_t;
> +typedef unsigned long kmem_bufctl_t;
>
> #endif /* __ASSEMBLY__ */
>
> diff -puN include/asm-h8300/types.h~slab-leak-detector include/asm-h8300/types.h
> --- 25/include/asm-h8300/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
> +++ 25-akpm/include/asm-h8300/types.h 2005-03-02 08:30:59.000000000 -0800
> @@ -58,7 +58,7 @@ typedef u32 dma_addr_t;
> #define HAVE_SECTOR_T
> typedef u64 sector_t;
>
> -typedef unsigned int kmem_bufctl_t;
> +typedef unsigned long kmem_bufctl_t;
>
> #endif /* __KERNEL__ */
>
> diff -puN include/asm-i386/types.h~slab-leak-detector include/asm-i386/types.h
> --- 25/include/asm-i386/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
> +++ 25-akpm/include/asm-i386/types.h 2005-03-02 08:30:59.000000000 -0800
> @@ -63,7 +63,7 @@ typedef u64 sector_t;
> #define HAVE_SECTOR_T
> #endif
>
> -typedef unsigned short kmem_bufctl_t;
> +typedef unsigned long kmem_bufctl_t;
>
> #endif /* __ASSEMBLY__ */
>
> diff -puN include/asm-ia64/types.h~slab-leak-detector include/asm-ia64/types.h
> --- 25/include/asm-ia64/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
> +++ 25-akpm/include/asm-ia64/types.h 2005-03-02 08:30:59.000000000 -0800
> @@ -67,7 +67,7 @@ typedef __u64 u64;
>
> typedef u64 dma_addr_t;
>
> -typedef unsigned short kmem_bufctl_t;
> +typedef unsigned long kmem_bufctl_t;
>
> # endif /* __KERNEL__ */
> #endif /* !__ASSEMBLY__ */
> diff -puN include/asm-m32r/types.h~slab-leak-detector include/asm-m32r/types.h
> --- 25/include/asm-m32r/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
> +++ 25-akpm/include/asm-m32r/types.h 2005-03-02 08:30:59.000000000 -0800
> @@ -55,7 +55,7 @@ typedef unsigned long long u64;
> typedef u32 dma_addr_t;
> typedef u64 dma64_addr_t;
>
> -typedef unsigned short kmem_bufctl_t;
> +typedef unsigned long kmem_bufctl_t;
>
> #endif /* __ASSEMBLY__ */
>
> diff -puN include/asm-m68k/types.h~slab-leak-detector include/asm-m68k/types.h
> --- 25/include/asm-m68k/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
> +++ 25-akpm/include/asm-m68k/types.h 2005-03-02 08:30:59.000000000 -0800
> @@ -60,7 +60,7 @@ typedef unsigned long long u64;
> typedef u32 dma_addr_t;
> typedef u32 dma64_addr_t;
>
> -typedef unsigned short kmem_bufctl_t;
> +typedef unsigned long kmem_bufctl_t;
>
> #endif /* __ASSEMBLY__ */
>
> diff -puN include/asm-mips/types.h~slab-leak-detector include/asm-mips/types.h
> --- 25/include/asm-mips/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
> +++ 25-akpm/include/asm-mips/types.h 2005-03-02 08:30:59.000000000 -0800
> @@ -99,7 +99,7 @@ typedef u64 sector_t;
> #define HAVE_SECTOR_T
> #endif
>
> -typedef unsigned short kmem_bufctl_t;
> +typedef unsigned long kmem_bufctl_t;
>
> #endif /* __ASSEMBLY__ */
>
> diff -puN include/asm-parisc/types.h~slab-leak-detector include/asm-parisc/types.h
> --- 25/include/asm-parisc/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
> +++ 25-akpm/include/asm-parisc/types.h 2005-03-02 08:30:59.000000000 -0800
> @@ -56,7 +56,7 @@ typedef unsigned long long u64;
> typedef u32 dma_addr_t;
> typedef u64 dma64_addr_t;
>
> -typedef unsigned int kmem_bufctl_t;
> +typedef unsigned long kmem_bufctl_t;
>
> #endif /* __ASSEMBLY__ */
>
> diff -puN include/asm-ppc64/types.h~slab-leak-detector include/asm-ppc64/types.h
> --- 25/include/asm-ppc64/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
> +++ 25-akpm/include/asm-ppc64/types.h 2005-03-02 08:30:59.000000000 -0800
> @@ -72,7 +72,7 @@ typedef struct {
> unsigned long env;
> } func_descr_t;
>
> -typedef unsigned int kmem_bufctl_t;
> +typedef unsigned long kmem_bufctl_t;
> #endif /* __ASSEMBLY__ */
>
> #endif /* __KERNEL__ */
> diff -puN include/asm-ppc/types.h~slab-leak-detector include/asm-ppc/types.h
> --- 25/include/asm-ppc/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
> +++ 25-akpm/include/asm-ppc/types.h 2005-03-02 08:30:59.000000000 -0800
> @@ -62,7 +62,7 @@ typedef u64 sector_t;
> #define HAVE_SECTOR_T
> #endif
>
> -typedef unsigned int kmem_bufctl_t;
> +typedef unsigned long kmem_bufctl_t;
>
> #endif /* __ASSEMBLY__ */
>
> diff -puN include/asm-s390/types.h~slab-leak-detector include/asm-s390/types.h
> --- 25/include/asm-s390/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
> +++ 25-akpm/include/asm-s390/types.h 2005-03-02 08:30:59.000000000 -0800
> @@ -79,7 +79,7 @@ typedef unsigned long u64;
>
> typedef u32 dma_addr_t;
>
> -typedef unsigned int kmem_bufctl_t;
> +typedef unsigned long kmem_bufctl_t;
>
> #ifndef __s390x__
> typedef union {
> diff -puN include/asm-sh64/types.h~slab-leak-detector include/asm-sh64/types.h
> --- 25/include/asm-sh64/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
> +++ 25-akpm/include/asm-sh64/types.h 2005-03-02 08:30:59.000000000 -0800
> @@ -65,7 +65,7 @@ typedef u32 dma_addr_t;
> #endif
> typedef u64 dma64_addr_t;
>
> -typedef unsigned int kmem_bufctl_t;
> +typedef unsigned long kmem_bufctl_t;
>
> #endif /* __ASSEMBLY__ */
>
> diff -puN include/asm-sh/types.h~slab-leak-detector include/asm-sh/types.h
> --- 25/include/asm-sh/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
> +++ 25-akpm/include/asm-sh/types.h 2005-03-02 08:30:59.000000000 -0800
> @@ -58,7 +58,7 @@ typedef u64 sector_t;
> #define HAVE_SECTOR_T
> #endif
>
> -typedef unsigned int kmem_bufctl_t;
> +typedef unsigned long kmem_bufctl_t;
>
> #endif /* __ASSEMBLY__ */
>
> diff -puN include/asm-sparc64/types.h~slab-leak-detector include/asm-sparc64/types.h
> --- 25/include/asm-sparc64/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
> +++ 25-akpm/include/asm-sparc64/types.h 2005-03-02 08:30:59.000000000 -0800
> @@ -56,7 +56,7 @@ typedef unsigned long u64;
> typedef u32 dma_addr_t;
> typedef u64 dma64_addr_t;
>
> -typedef unsigned short kmem_bufctl_t;
> +typedef unsigned long kmem_bufctl_t;
>
> #endif /* __ASSEMBLY__ */
>
> diff -puN include/asm-sparc/types.h~slab-leak-detector include/asm-sparc/types.h
> --- 25/include/asm-sparc/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
> +++ 25-akpm/include/asm-sparc/types.h 2005-03-02 08:30:59.000000000 -0800
> @@ -54,7 +54,7 @@ typedef unsigned long long u64;
> typedef u32 dma_addr_t;
> typedef u32 dma64_addr_t;
>
> -typedef unsigned short kmem_bufctl_t;
> +typedef unsigned long kmem_bufctl_t;
>
> #endif /* __ASSEMBLY__ */
>
> diff -puN include/asm-v850/types.h~slab-leak-detector include/asm-v850/types.h
> --- 25/include/asm-v850/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
> +++ 25-akpm/include/asm-v850/types.h 2005-03-02 08:30:59.000000000 -0800
> @@ -59,7 +59,7 @@ typedef unsigned long long u64;
>
> typedef u32 dma_addr_t;
>
> -typedef unsigned int kmem_bufctl_t;
> +typedef unsigned long kmem_bufctl_t;
>
> #endif /* !__ASSEMBLY__ */
>
> diff -puN include/asm-x86_64/types.h~slab-leak-detector include/asm-x86_64/types.h
> --- 25/include/asm-x86_64/types.h~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
> +++ 25-akpm/include/asm-x86_64/types.h 2005-03-02 08:30:59.000000000 -0800
> @@ -51,7 +51,7 @@ typedef u64 dma_addr_t;
> typedef u64 sector_t;
> #define HAVE_SECTOR_T
>
> -typedef unsigned short kmem_bufctl_t;
> +typedef unsigned long kmem_bufctl_t;
>
> #endif /* __ASSEMBLY__ */
>
> diff -puN mm/slab.c~slab-leak-detector mm/slab.c
> --- 25/mm/slab.c~slab-leak-detector 2005-03-02 08:30:59.000000000 -0800
> +++ 25-akpm/mm/slab.c 2005-03-02 08:30:59.000000000 -0800
> @@ -2116,6 +2116,15 @@ cache_alloc_debugcheck_after(kmem_cache_
> *dbg_redzone1(cachep, objp) = RED_ACTIVE;
> *dbg_redzone2(cachep, objp) = RED_ACTIVE;
> }
> + {
> + int objnr;
> + struct slab *slabp;
> +
> + slabp = GET_PAGE_SLAB(virt_to_page(objp));
> +
> + objnr = (objp - slabp->s_mem) / cachep->objsize;
> + slab_bufctl(slabp)[objnr] = (unsigned long)caller;
> + }
> objp += obj_dbghead(cachep);
> if (cachep->ctor && cachep->flags & SLAB_POISON) {
> unsigned long ctor_flags = SLAB_CTOR_CONSTRUCTOR;
> @@ -2179,12 +2188,14 @@ static void free_block(kmem_cache_t *cac
> objnr = (objp - slabp->s_mem) / cachep->objsize;
> check_slabp(cachep, slabp);
> #if DEBUG
> +#if 0
> if (slab_bufctl(slabp)[objnr] != BUFCTL_FREE) {
> printk(KERN_ERR "slab: double free detected in cache '%s', objp %p.\n",
> cachep->name, objp);
> BUG();
> }
> #endif
> +#endif
> slab_bufctl(slabp)[objnr] = slabp->free;
> slabp->free = objnr;
> STATS_DEC_ACTIVE(cachep);
> @@ -2998,6 +3009,29 @@ struct seq_operations slabinfo_op = {
> .show = s_show,
> };
>
> +static void do_dump_slabp(kmem_cache_t *cachep)
> +{
> +#if DEBUG
> + struct list_head *q;
> +
> + check_irq_on();
> + spin_lock_irq(&cachep->spinlock);
> + list_for_each(q,&cachep->lists.slabs_full) {
> + struct slab *slabp;
> + int i;
> + slabp = list_entry(q, struct slab, list);
> + for (i = 0; i < cachep->num; i++) {
> + unsigned long sym = slab_bufctl(slabp)[i];
> +
> + printk("obj %p/%d: %p", slabp, i, (void *)sym);
> + print_symbol(" <%s>", sym);
> + printk("\n");
> + }
> + }
> + spin_unlock_irq(&cachep->spinlock);
> +#endif
> +}
> +
> #define MAX_SLABINFO_WRITE 128
> /**
> * slabinfo_write - Tuning for the slab allocator
> @@ -3038,9 +3072,11 @@ ssize_t slabinfo_write(struct file *file
> batchcount < 1 ||
> batchcount > limit ||
> shared < 0) {
> - res = -EINVAL;
> + do_dump_slabp(cachep);
> + res = 0;
> } else {
> - res = do_tune_cpucache(cachep, limit, batchcount, shared);
> + res = do_tune_cpucache(cachep, limit,
> + batchcount, shared);
> }
> break;
> }
> _
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
>
Justin Schoeman <[email protected]> wrote:
>
> Will the slab debugger make it into the kernel as a standard compile
> time option? It is a _really_ usefull tool to have around.
It has a slight downside: it unconditionally changes the type of
kmem_bufctl_t to unsigned long, which wastes two or four bytes per page of
slab.
I suppose we could fix that up with suitable use of CONFIG_DEBUG_SLAB.