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

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Message-ID: <CAOG64qP2qiyOQaTJ56Cg2w=Q=euDbSjqkOVOLKJHMq-xAS2U7Q@mail.gmail.com>
Date:   Tue, 22 Mar 2022 19:36:11 +0700
From:   Alviro Iskandar Setiawan <alviro.iskandar@...weeb.org>
To:     Ammar Faizi <ammarfaizi2@...weeb.org>
Cc:     David Laight <David.Laight@...lab.com>, Willy Tarreau <w@....eu>,
        "Paul E. McKenney" <paulmck@...nel.org>,
        Nugraha <richiisei@...il.com>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        "GNU/Weeb Mailing List" <gwml@...r.gnuweeb.org>
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