Re: [Patch v1 07/10] perf tools: add mem access sampling core support

Stephane Eranian
2012-10-31T13:30:34Z

On Wed, Oct 31, 2012 at 6:51 AM, Namhyung Kim <namhyung@kernel.org> wrote:
> On Mon, 29 Oct 2012 16:15:49 +0100, Stephane Eranian wrote:
>> This patch adds the sorting and histogram support
>> functions to enable profiling of memory accesses.
>>
>> The following sorting orders are added:
>> - symbol_daddr: data address symbol (or raw address)
>> - dso_daddr: data address shared object
>> - cost: access cost
>> - locked: access uses locked transaction
>> - tlb : TLB access
>> - mem : memory level of the access (L1, L2, L3, RAM, ...)
>> - snoop: access snoop mode
>>
>> Signed-off-by: Stephane Eranian <eranian@google.com>
>> ---
> [snip]
>> +/* --sort daddr_sym */
>> +static int64_t
>> +sort__daddr_cmp(struct hist_entry *left, struct hist_entry *right)
>> +{
>> + struct addr_map_symbol *l = &left->mem_info->daddr;
>> + struct addr_map_symbol *r = &right->mem_info->daddr;
>> +
>> + return (int64_t)(r->addr - l->addr);
>> +}
>
> Doesn't it need to compare symbol (start address) if any, before doing
> it with raw addresses?
>
Possibly but we can't get to data symbols at the moment due to limitations
in kernel + perf tool.