Re: [PATCH 1/2] Memory statistics enhancement.

[Martin Liška <mliska at suse dot cz>]

On 06/02/2015 07:17 PM, Jeff Law wrote:
> On 06/02/2015 09:05 AM, Martin Liška wrote:
>> On 06/02/2015 03:58 PM, Jeff Law wrote:
>>> On 06/01/2015 10:16 AM, mliska wrote:
>>>> Hi.
>>>>
>>>> Following 2 patches improve memory statistics infrastructure. First one
>>>> ports pool allocator to the new infrastructure. And the second one makes
>>>> column alignment properly.
>>>>
>>>> Both can bootstrap on x86_64-linux-pc and survive regression tests.
>>>>
>>>> Ready for trunk?
>>>> Thank you,
>>>> Martin
>>>>
>>>> Port pool-allocator memory stats to a new infrastructure.
>>>>
>>>> gcc/ChangeLog:
>>>>
>>>> 2015-06-02  Martin Liska  <mliska@suse.cz>
>>>>
>>>>      * alloc-pool.c (allocate_pool_descriptor): Remove.
>>>>      (struct pool_output_info): Likewise.
>>>>      (print_alloc_pool_statistics): Likewise.
>>>>      (dump_alloc_pool_statistics): Likewise.
>>>>      * alloc-pool.h (struct pool_usage): New struct.
>>>>      (pool_allocator::initialize): Change usage of memory statistics
>>>>      to a new interface.
>>>>      (pool_allocator::release): Likewise.
>>>>      (pool_allocator::allocate): Likewise.
>>>>      (pool_allocator::remove): Likewise.
>>>>      * mem-stats-traits.h (enum mem_alloc_origin): Add new enum value
>>>>      for a pool allocator.
>>>>      * mem-stats.h (struct mem_location): Add new ctor.
>>>>      (struct mem_usage): Add counter for number of
>>>>      instances.
>>>>      (mem_alloc_description::register_descriptor): New overload of
>>>>      the function.
>>>   -
>>>
>>>> diff --git a/gcc/alloc-pool.h b/gcc/alloc-pool.h
>>>> index 96a1342..a1727ce 100644
>>>> --- a/gcc/alloc-pool.h
>>>> +++ b/gcc/alloc-pool.h
>>>
>>>> +  /* Dump usage coupled to LOC location, where TOTAL is sum of all rows.  */
>>>> +  inline void dump (mem_location *loc, mem_usage &total) const
>>>> +  {
>>>> +    char s[4096];
>>>> +    sprintf (s, "%s:%i (%s)", loc->get_trimmed_filename (),
>>>> +         loc->m_line, loc->m_function);
>>> Static sized buffer used in a sprintf where the strings are potentially user controlled.   Not good, even in dumping code, still not good.
>>>
>>>> +
>>>> +    s[48] = '\0';
>>> ?!?  Presumably you're just truncating the output line here for the subsequent fprintf call.  Consider using a const with a symbolic name rather than the magic "48".  I say "consider" because there's magic constants all over the place in the dumping code. So it may not be worth the effort.  Your call.
>>>
>>>   +
>>>> +  /* Dump header with NAME.  */
>>>> +  static inline void dump_header (const char *name)
>>>> +  {
>>>> +    fprintf (stderr, "%-32s%-48s %6s%11s%16s%17s%12s\n", "Pool name", name,
>>>> +         "Pools", "Leak", "Peak", "Times", "Elt size");
>>>> +    print_dash_line ();
>>>> +  }
>>>> +
>>>> +  /* Dump footer.  */
>>>> +  inline void dump_footer ()
>>>> +  {
>>>> +    print_dash_line ();
>>>> +    fprintf (stderr, "%s%75li%10li\n", "Total", (long)m_instances,
>>>> +         (long)m_allocated);
>>>> +    print_dash_line ();
>>>> +  }
>>> Note the header is static inline, footer is just inline.  Please try to make them consistent.
> It doesn't look like you did anything with this.  Is there a reason that the dump_header and dump_footer have different linkage?  Also the linkage/return type for dump_header should be on its own line.
> 
> With that fixed, this is OK for the trunk.
> 
> jeff

Hi Jeff.

Different linkage is because of dump_header is just a generic header unrelated to any real numbers.
On the other hand, dump_footer is called on a total instance.

I've just identified that the whole memory statistics infrastructure lacks correct GNU formatting
in case of C++ member functions. I'm going to fix it in a different patch.

Thanks,
Martin