>> Index: sys/kern/kern_malloc.c
>> ===================================================================
>> RCS file: /cvs/src/sys/kern/kern_malloc.c,v
>> retrieving revision 1.128
>> diff -u -p -r1.128 kern_malloc.c
>> --- sys/kern/kern_malloc.c 14 Mar 2015 03:38:50 -0000 1.128
>> +++ sys/kern/kern_malloc.c 9 Dec 2015 16:50:57 -0000
>> @@ -158,6 +158,8 @@ malloc(size_t size, int type, int flags)
>> char *savedtype;
>> #endif
>> #ifdef KMEMSTATS
>> + int i;
>> + struct ktopcount *kftop;
>> struct kmemstats *ksp = &kmemstats[type];
>>
>> if (((unsigned long)type) <= 1 || ((unsigned long)type) >= M_LAST)
>> @@ -338,6 +340,29 @@ out:
>> ksp->ks_calls++;
>> if (ksp->ks_memuse > ksp->ks_maxused)
>> ksp->ks_maxused = ksp->ks_memuse;
>> +
>> + void *from = __builtin_return_address(0);
>> + from = __builtin_extract_return_addr(from);
>> + if (!from)
>> + goto topout;
>
> Dropping gcc extensions into the middle of the kernel isn't recommended. Also,
> this mixes code and declarations.
Ted, thanks for your comments once again!
I didn't know about it. I looked at db_stack_dump() as an example, it
uses __builtin_frame_address.
>> +
>> + kftop = &ksp->ks_top[0];
>> + for (i = 0; i < KMEMSTATS_TOPCOUNT; ++i)
>> + {
>> + if (ksp->ks_top[i].kt_from == from) {
>> + ksp->ks_top[i].kt_calls++;
>> + ksp->ks_top[i].kt_memuse += allocsize;
>> + goto topout;
>> + }
>> + else if (ksp->ks_top[i].kt_memuse < kftop->kt_memuse)
>> + kftop = &ksp->ks_top[i];
>> + }
>> +
>> + kftop->kt_calls = 1;
>> + kftop->kt_memuse = allocsize;
>> + kftop->kt_from = from;
>
> I'm not sure what you're trying to do here. The replacement policy seems to
> overwrite the first entry every time. I think you'd have to get pretty lucky
> for this to actually track the biggest user.
The replacement policy looks like this: I take the first entry and
assume that it has a min value of kt_kmemuse. Then I loop through
kt_top structs and search for a minimum. At the first iteration it
checks ks_top[0] with ks_top[0], but I need it due to first if
(kt_from == from).
