lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Message-ID: <MDEHLPKNGKAHNMBLJOLKEEOPDBAC.davids@webmaster.com>
Date:	Tue, 17 Apr 2007 21:47:28 -0700
From:	"David Schwartz" <davids@...master.com>
To:	<linux-kernel@...r.kernel.org>
Subject: RE: Memory Allocation


> My test machine is a Dell Precision 490 with dual 5140 processors and
> 3GB of RAM.  If I reduced kMaxSize to (2048 * 2048 * 236) is works.
> However, I need to allocate an array of char that is (2048 * 2048 * 256)
> and maybe even as large at (2048 * 2048 * 512).
>
> Obviously I have enough physical memory in the box to do this.  However,
> I suspect that I'm running out of page table entries.  Please, correct
> me if I'm wrong; but if I allocate (2048 * 2048 * 236) it work.  When I
> increment to 256 or 512 it fails and it is my suspicion that I just
> don't have enough more in kernel memory to allocate this much memory in
> user space.

It is unreasonable to expect single allocations this large to succeed on a
32-bit OS. Either get a 64-bit OS or use a number of smaller allocations.

You may want to use mmap'ed files instead of malloc'ed memory. You can them
mmap however many files you can at once, and unmap and remap them as needed.

DS



-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ