[PATCH 2/9] malloc: remove malloc_consolidate

[Dev Jain]

On 12/11/25 8:55 am, DJ Delorie wrote:
> Dev Jain <dev.jain@arm.com> writes:
>> diff --git a/malloc/malloc.c b/malloc/malloc.c
>>   
>> -  /* Set if the fastbin chunks contain recently inserted free blocks.  */
>> -  /* Note this is a bool but not all targets support atomics on booleans.  */
>> -  int have_fastchunks;
>> -
> Ok.
>
>>     set_noncontiguous (av);
>>     if (av == &main_arena)
>>       set_max_fast (DEFAULT_MXFAST);
>> -  atomic_store_relaxed (&av->have_fastchunks, false);
> Ok.
>
>> -static void     malloc_consolidate (mstate);
> Ok.
>
>>       {
>>         idx = largebin_index (nb);
>> -      if (atomic_load_relaxed (&av->have_fastchunks))
>> -        malloc_consolidate (av);
>>       }
> Ok.
>
>>   
>> -      /* When we are using atomic ops to free fast chunks we can get
>> -         here for all block sizes.  */
>> -      else if (atomic_load_relaxed (&av->have_fastchunks))
>> -        {
>> -          malloc_consolidate (av);
>> -          /* restore original bin index */
>> -          if (in_smallbin_range (nb))
>> -            idx = smallbin_index (nb);
>> -          else
>> -            idx = largebin_index (nb);
>> -        }
>> -
> Ok.
>
>>       free_perturb (chunk2mem(p), size - CHUNK_HDR_SZ);
>>   
>> -    atomic_store_relaxed (&av->have_fastchunks, true);
> Ok.
>
>>     if (size >= FASTBIN_CONSOLIDATION_THRESHOLD)
> I notice that none of these patches remove this macro...  Perhaps it
> should be renamed later to better reflect its new purpose (trimming) ?

True, I didn't want to bother reading the trimming code to decide what
to name this to. I'll think about it!

>
>>       {
>> -      if (atomic_load_relaxed (&av->have_fastchunks))
>> -	malloc_consolidate(av);
>> -
> Ok.
>
>> -/*
>> -  ------------------------- malloc_consolidate -------------------------
>> -
>> -  malloc_consolidate is a specialized version of free() that tears
>> -  down chunks held in fastbins.  Free itself cannot be used for this
>> -  purpose since, among other things, it might place chunks back onto
>> . . .
>> -  } while (fb++ != maxfb);
>> -}
>> -
> Ok.
>
>>   static int
>>   mtrim (mstate av, size_t pad)
>>   {
>> -  /* Ensure all blocks are consolidated.  */
>> -  malloc_consolidate (av);
>> -
> Ok.
>
>> -  /* We must consolidate main arena before changing max_fast
>> -     (see definition of set_max_fast).  */
>> -  malloc_consolidate (av);
>> -
> Ok.
>
> LGTM
> Reviewed-by: DJ Delorie <dj@redhat.com>
>