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From: "Ulrich Drepper" <drepper@gmail.com>
To: "Rik van Riel" <riel@redhat.com>
Cc: "Davide Libenzi" <davidel@xmailserver.org>,
	"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>
Subject: Re: [patch 2/3] MAP_NOZERO - implement sys_brk2()
Date: Tue, 26 Jun 2007 22:04:11 -0700	[thread overview]
Message-ID: <a36005b50706262204s2a6decds70bd56955217de13@mail.gmail.com> (raw)
In-Reply-To: <4681E37A.9090708@redhat.com>

On 6/26/07, Rik van Riel <riel@redhat.com> wrote:
> After going through the first malloc()/free() cycle, surely
> the memory will no longer be zeroed on the second malloc() ?

If returned to the system, sure.


> What makes the first brk malloc so special?

If the memory is zeroed it needs not be initialized by malloc.  No
calloc zeroing, no pointer clearing.

Anyway, it's irrelevant what the benefits are, the fact is current
code depends on brk to zero the memory and you'd break the ABI if
you'd change it.

  reply	other threads:[~2007-06-27  5:04 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-06-27  2:44 [patch 2/3] MAP_NOZERO - implement sys_brk2() Davide Libenzi
2007-06-27  3:07 ` Rik van Riel
2007-06-27  3:33   ` Davide Libenzi
2007-06-27  3:45   ` Ulrich Drepper
2007-06-27  4:11     ` Rik van Riel
2007-06-27  5:04       ` Ulrich Drepper [this message]
2007-06-27  3:48 ` Ulrich Drepper
2007-06-27  3:55   ` Davide Libenzi
2007-06-27  5:02     ` Ulrich Drepper
2007-06-27 12:32       ` Hugh Dickins
2007-06-27 15:59         ` Davide Libenzi
2007-06-27 17:01         ` Ulrich Drepper
2007-06-27 17:43           ` Hugh Dickins
2007-06-27 18:13             ` Davide Libenzi
2007-06-27 18:32               ` Hugh Dickins
2007-06-27 18:45                 ` Davide Libenzi
2007-06-27 22:11                   ` Nicholas Miell
2007-06-28  0:17                     ` Davide Libenzi
2007-06-28  2:58                       ` Davide Libenzi
2007-06-30  7:52                     ` Andrew Morton
2007-06-27 18:52             ` Ulrich Drepper
2007-06-27 19:32               ` Hugh Dickins
2007-06-27 19:00           ` Rik van Riel
2007-06-27 19:22             ` Davide Libenzi
2007-06-27 16:05       ` Davide Libenzi

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