Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754135Ab0LGO2N (ORCPT ); Tue, 7 Dec 2010 09:28:13 -0500 Received: from adelie.canonical.com ([91.189.90.139]:33841 "EHLO adelie.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753220Ab0LGO2M (ORCPT ); Tue, 7 Dec 2010 09:28:12 -0500 Date: Tue, 7 Dec 2010 08:27:47 -0600 From: "Serge E. Hallyn" To: Pavel Emelyanov Cc: Andrew Morton , Linux Containers , Linux Kernel Mailing List Subject: Re: [PATCH] user_ns: Improve the user_ns on-the-slab packaging Message-ID: <20101207142747.GB4674@hallyn.com> References: <4CFE40D1.5000309@parallels.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4CFE40D1.5000309@parallels.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 668 Lines: 18 Quoting Pavel Emelyanov (xemul@parallels.com): > Currently on 64-bit arch the user_namespace is 2096 and when > being kmalloc-ed it resides on a 4k slab wasting 2003 bytes. > > If we allocate a separate cache for it and reduce the hash size > from 128 to 64 chains the packaging becomes *much* better - the Hey Pavel, I trust you've done some performance tests and found no regressions with a few hundred users? -serge -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/