Messages in this thread | | | Subject | Re: -rc3 leaking NOT BIO [Was: Memory leak in 2.6.11-rc1?] | From | Badari Pulavarty <> | Date | 17 Feb 2005 17:38:35 -0800 |
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On Thu, 2005-02-17 at 05:00, Parag Warudkar wrote: > On Wednesday 16 February 2005 06:52 pm, Andrew Morton wrote: > > So it's probably an ndiswrapper bug? > Andrew, > It looks like it is a kernel bug triggered by NdisWrapper. Without > NdisWrapper, and with just 8139too plus some light network activity the > size-64 grew from ~ 1100 to 4500 overnight. Is this normal? I will keep it > running to see where it goes. > > A question - is it safe to assume it is a kmalloc based leak? (I am thinking > of tracking it down by using kprobes to insert a probe into __kmalloc and > record the stack to see what is causing so many allocations.) >
Last time I debugged something like this, I ended up adding dump_stack() in kmem_cache_alloc() for the specific slab.
If you are really interested, you can try to get following jprobe module working. (need to teach about kmem_cache_t structure to get it to compile and export kallsyms_lookup_name() symbol etc).
Thanks, Badari
#include <linux/module.h> #include <linux/kprobes.h> #include <linux/kallsyms.h> #include <linux/kdev_t.h>
MODULE_PARM_DESC(kmod, "\n");
int count = 0; void fastcall inst_kmem_cache_alloc(kmem_cache_t *cachep, int flags) { if (cachep->objsize == 64) { if (count++ == 100) { dump_stack(); count = 0; } } jprobe_return(); } static char *fn_names[] = { "kmem_cache_alloc", };
static struct jprobe kmem_probes[] = { { .entry = (kprobe_opcode_t *) inst_kmem_cache_alloc, .kp.addr=(kprobe_opcode_t *) 0, } };
#define MAX_KMEM_ROUTINE (sizeof(kmem_probes)/sizeof(struct kprobe))
/* installs the probes in the appropriate places */ static int init_kmods(void) { int i;
for (i = 0; i < MAX_KMEM_ROUTINE; i++) { kmem_probes[i].kp.addr = kallsyms_lookup_name(fn_names[i]); if (kmem_probes[i].kp.addr) { printk("plant jprobe at name %s %p, handler addr %p\n", fn_names[i], kmem_probes[i].kp.addr, kmem_probes[i].entry); register_jprobe(&kmem_probes[i]); } } return 0; }
static void cleanup_kmods(void) { int i; for (i = 0; i < MAX_KMEM_ROUTINE; i++) { unregister_jprobe(&kmem_probes[i]); } }
module_init(init_kmods); module_exit(cleanup_kmods); MODULE_LICENSE("GPL");
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