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] [thread-next>] [day] [month] [year] [list]
Date:	Thu, 20 Dec 2012 12:28:13 -0800 (PST)
From:	David Rientjes <rientjes@...gle.com>
To:	Sasha Levin <sasha.levin@...cle.com>
cc:	Andrew Morton <akpm@...ux-foundation.org>,
	"Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>,
	Xiao Guangrong <xiaoguangrong@...ux.vnet.ibm.com>,
	Andrea Arcangeli <aarcange@...hat.com>, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 04/15] mm/huge_memory: use new hashtable implementation

On Wed, 19 Dec 2012, Sasha Levin wrote:

> In this case, the downside is that you'll waste 8KB if hugepages aren't available,
> but the upside is that you'll have one less dereference when accessing the
> hashtable.
> 
> If the 8KB saving is preferable here I'll drop the patch and come back when
> dynamic hashtable is supported.
> 

If a distro releases with CONFIG_TRANSPARNET_HUGEPAGE=y and a user is 
running on a processor that does not support pse then this just cost them 
8KB for no reason.  The overhead by simply enabling 
CONFIG_TRANSPARENT_HUGEPAGE is worse in this scenario, but this is whole 
reason for having the dynamic allocation in the original code.  If there's 
a compelling reason for why we want this change, then that fact should at 
least be documented.

Could you propose a v2 that includes fixes for the other problems that 
were mentioned?
--
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