From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753958AbaCGRRY (ORCPT ); Fri, 7 Mar 2014 12:17:24 -0500 Received: from mga11.intel.com ([192.55.52.93]:30712 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752504AbaCGRRV (ORCPT ); Fri, 7 Mar 2014 12:17:21 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,608,1389772800"; d="scan'208";a="494279612" From: Andi Kleen To: Al Viro Cc: linux-fsdevel@vger.kernel.org, Linus Torvalds , linux-kernel@vger.kernel.org, Stephen Tweedie , Jeremy Eder Subject: Re: [PATCH 5/5][RFC][CFT] resizable namespace.c hashes References: <20140305034751.GW18016@ZenIV.linux.org.uk> <20140305035219.GE26528@ZenIV.linux.org.uk> Date: Fri, 07 Mar 2014 09:17:19 -0800 In-Reply-To: <20140305035219.GE26528@ZenIV.linux.org.uk> (Al Viro's message of "Wed, 5 Mar 2014 03:52:19 +0000") Message-ID: <87bnxi6i8w.fsf@tassilo.jf.intel.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Al Viro writes: > * switch allocation to alloc_large_system_hash() > * make sizes overridable by boot parameters (mhash_entries=, mphash_entries=) > * switch mountpoint_hashtable from list_head to hlist_head So how much memory does this use on a standard system (<4GB memory)? How much memory does it use on a large system (0.5TB)? How good is your hash function. Would jhash be more appropiate and allow smaller hash tables? Perhaps just want a tree here. -Andi -- ak@linux.intel.com -- Speaking for myself only