2022-03-22 14:01:27

by Alviro Iskandar Setiawan

Subject: Re: [RFC PATCH v2 6/8] tools/nolibc/stdlib: Implement `malloc()`, `calloc()`, `realloc()` and `free()`

On Tue, Mar 22, 2022 at 7:18 PM Ammar Faizi wrote:
> Rounding up is not useful here, because we don't have any free list to keep
> track the unused block of memory. I mean, even if it's rounded up, the extra
> space after rounded up cannot be utilized with this design. There is no
> book-keeping that tracks it.
>
> Though, the kernel still allocates the size in multiple page size.

BTW, what David meant probably, don't call mmap() again if heap->len
is greater than new_len. Isn't that simple enough to give it a go?

-- Viro

2022-03-22 17:26:56

by Ammar Faizi

Subject: Re: [RFC PATCH v2 6/8] tools/nolibc/stdlib: Implement `malloc()`, `calloc()`, `realloc()` and `free()`

On 3/22/22 7:36 PM, Alviro Iskandar Setiawan wrote:
> On Tue, Mar 22, 2022 at 7:18 PM Ammar Faizi wrote:
>> Rounding up is not useful here, because we don't have any free list to keep
>> track the unused block of memory. I mean, even if it's rounded up, the extra
>> space after rounded up cannot be utilized with this design. There is no
>> book-keeping that tracks it.
>>
>> Though, the kernel still allocates the size in multiple page size.
>
> BTW, what David meant probably, don't call mmap() again if heap->len
> is greater than new_len. Isn't that simple enough to give it a go?

Ah yes, I get the idea now, it shouldn't be a burden for this series. I
think that small improvement is not too overkill. So I will take that
suggestion for the next series.

Thanks!

--
Ammar Faizi