From: "Ulrich Drepper" <drepper@gmail.com>
To: "Davide Libenzi" <davidel@xmailserver.org>
Cc: "Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>
Subject: Re: [patch 2/3] MAP_NOZERO - implement sys_brk2()
Date: Tue, 26 Jun 2007 22:02:33 -0700 [thread overview]
Message-ID: <a36005b50706262202w4aaa4494qc2322e49c71d8d7c@mail.gmail.com> (raw)
In-Reply-To: <Pine.LNX.4.64.0706262052060.26540@alien.or.mcafeemobile.com>
On 6/26/07, Davide Libenzi <davidel@xmailserver.org> wrote:
> I acutally have the code for it, but I never posted it since it did not
> receive a too warm review (and the only user was the fdmap thingy).
Only user of sys_indirect? There will be quite a few right away.
Every syscall that returns a file descriptor needs O_CLOEXEC support
(socket, pipe, epoll_create, ...)
> OTOH glibc could implement __morecore using mmap(MAP_NOZERO), and hence
> brk2() would not be needed, no?
No. mmap calls create individual VMAs which gets expensive. There
are also some hardware drivers which get more expensive the more VMAs
there are. I want to go away as much as possible from mmap for
malloc.
next prev parent reply other threads:[~2007-06-27 5:02 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
2007-06-27 3:48 ` Ulrich Drepper
2007-06-27 3:55 ` Davide Libenzi
2007-06-27 5:02 ` Ulrich Drepper [this message]
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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