From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <ecos-bugs-return-9665-listarch-ecos-bugs=sources.redhat.com@sourceware.org>
Received: (qmail 11426 invoked by alias); 27 Jul 2012 09:12:28 -0000
Received: (qmail 11405 invoked by uid 22791); 27 Jul 2012 09:12:27 -0000
X-SWARE-Spam-Status: No, hits=-2.8 required=5.0
	tests=AWL,BAYES_00,KHOP_THREADED
X-Spam-Check-By: sourceware.org
Received: from hagrid.ecoscentric.com (HELO mail.ecoscentric.com) (212.13.207.197)
    by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Fri, 27 Jul 2012 09:12:11 +0000
Received: from localhost (hagrid.ecoscentric.com [127.0.0.1])
	by mail.ecoscentric.com (Postfix) with ESMTP id BAC742F7800E
	for <ecos-bugs@ecos.sourceware.org>; Fri, 27 Jul 2012 10:12:10 +0100 (BST)
Received: from mail.ecoscentric.com ([127.0.0.1])
	by localhost (hagrid.ecoscentric.com [127.0.0.1]) (amavisd-new, port 10024)
	with ESMTP id d9dM3GI148Zv; Fri, 27 Jul 2012 10:12:05 +0100 (BST)
From: bugzilla-daemon@bugs.ecos.sourceware.org
To: ecos-bugs@ecos.sourceware.org
Subject: [Bug 1001634] A code review of dlmalloc.cxx revealed several
 weaknesses
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: eCos
X-Bugzilla-Component: Memory allocators
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: enhancement
X-Bugzilla-Who: bernd.edlinger@hotmail.de
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Priority: normal
X-Bugzilla-Assigned-To: unassigned@bugs.ecos.sourceware.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Changed-Fields: 
In-Reply-To: <bug-1001634-13@http.bugs.ecos.sourceware.org/>
References: <bug-1001634-13@http.bugs.ecos.sourceware.org/>
X-Bugzilla-URL: http://bugs.ecos.sourceware.org/
Auto-Submitted: auto-generated
Content-Type: text/plain; charset="UTF-8"
MIME-Version: 1.0
Date: Fri, 27 Jul 2012 09:12:00 -0000
Message-Id: <20120727091205.A3DF52F7800D@mail.ecoscentric.com>
Mailing-List: contact ecos-bugs-help@sourceware.org; run by ezmlm
Precedence: bulk
List-Id: <ecos-bugs.sourceware.org>
List-Subscribe: <mailto:ecos-bugs-subscribe@sourceware.org>
List-Post: <mailto:ecos-bugs@sourceware.org>
List-Help: <mailto:ecos-bugs-help@sourceware.org>, <http://sourceware.org/lists.html#faqs>
Sender: ecos-bugs-owner@sourceware.org
X-SW-Source: 2012/txt/msg01094.txt.bz2

Please do not reply to this email. Use the web interface provided at:
http://bugs.ecos.sourceware.org/show_bug.cgi?id=1001634

--- Comment #1 from Bernd Edlinger <bernd.edlinger@hotmail.de> 2012-07-27 10:12:03 BST ---
This is a test code to demonstrate the very slow performance
of the current implementation. The parameter k is the number
of kilobytes to use for the test.

The execution time of memtest(n) = O(n^2) without the patch.
When the patch is applied the execution time will be O(n).

#include <malloc.h>
void memtest(unsigned k)
{
    unsigned i;
    void **p,**q;
    p=q=malloc(504);
    for (i=0; i<k; i++)
    {
        q=*q=malloc(504+4*(i%16));
    }
    *q=0;
    q=p;
    for (i=0; i<k; i++)
    {
        void **n=*q;
        q=*q=*n;
        free(n);
        if (!q || !*q) q=p;
    }
    free(p);
}

-- 
Configure bugmail: http://bugs.ecos.sourceware.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.