[patch] malloc_trim.3: Remove mentioning of free call

[patch] malloc_trim.3: Remove mentioning of free call

[Dmitry Vorobev]

'malloc_trim' was and is never called from the 'free' function. see
related bug in glibc tracker:
https://sourceware.org/bugzilla/show_bug.cgi?id=2531. or '__int_free'
function. Only the top part of the heap is trimmed after some calls to
'free', which is different from 'malloc_trim' which also releases
memory in between chunks from all the arenas/heaps.

diff --git a/man3/malloc_trim.3 b/man3/malloc_trim.3
index 3c4cf5e8b..84e73fd70 100644
--- a/man3/malloc_trim.3
+++ b/man3/malloc_trim.3
@@ -80,15 +80,6 @@ T} Thread safety MT-Safe
 .SH CONFORMING TO
 This function is a GNU extension.
 .SH NOTES
-This function is automatically called by
-.BR free (3)
-in certain circumstances; see the discussion of
-.B M_TOP_PAD
-and
-.B M_TRIM_THRESHOLD
-in
-.BR mallopt (3).
-.PP
 Only the main heap (using
 .BR sbrk (2))
 honors the

Re: [patch] malloc_trim.3: Remove mentioning of free call

[Michael Kerrisk (man-pages)]

Hello Dmitry,

On 2/1/21 11:42 AM, Dmitry Vorobev wrote:
> 'malloc_trim' was and is never called from the 'free' function. see
> related bug in glibc tracker:
> https://sourceware.org/bugzilla/show_bug.cgi?id=2531. or '__int_free'
> function. Only the top part of the heap is trimmed after some calls to
> 'free', which is different from 'malloc_trim' which also releases
> memory in between chunks from all the arenas/heaps.

Thanks. I wrote that sentence, but looking back, I must
have been confused.

I've applied your patch.

Cheers,

Michael

> diff --git a/man3/malloc_trim.3 b/man3/malloc_trim.3
> index 3c4cf5e8b..84e73fd70 100644
> --- a/man3/malloc_trim.3
> +++ b/man3/malloc_trim.3
> @@ -80,15 +80,6 @@ T} Thread safety MT-Safe
>  .SH CONFORMING TO
>  This function is a GNU extension.
>  .SH NOTES
> -This function is automatically called by
> -.BR free (3)
> -in certain circumstances; see the discussion of
> -.B M_TOP_PAD
> -and
> -.B M_TRIM_THRESHOLD
> -in
> -.BR mallopt (3).
> -.PP
>  Only the main heap (using
>  .BR sbrk (2))
>  honors the
> 


-- 
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/