Re: Tracing memory leaks (slabs) in 2.6.9+ kernels?

From: Justin Schoeman
Date: Fri Mar 04 2005 - 02:51:21 EST

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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 <justin@xxxxxxxxxxxxxxx> 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;
}
_

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Next message: Pete Zaitcev: "Re: USB 2.4.30: fix modem_run"
Previous message: Dave Jones: "Re: 2.6.11 vs DVB cx88 stuffs"
In reply to: Andrew Morton: "Re: Tracing memory leaks (slabs) in 2.6.9+ kernels?"
Next in thread: Andrew Morton: "Re: Tracing memory leaks (slabs) in 2.6.9+ kernels?"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]