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");