Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934198Ab3HIO6E (ORCPT ); Fri, 9 Aug 2013 10:58:04 -0400 Received: from mail-qc0-f171.google.com ([209.85.216.171]:35671 "EHLO mail-qc0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933883Ab3HIO6C (ORCPT ); Fri, 9 Aug 2013 10:58:02 -0400 Date: Fri, 9 Aug 2013 10:57:56 -0400 From: Tejun Heo To: Kent Overstreet Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, Stephen Rothwell , Fengguang Wu Subject: Re: [PATCH] idr: Document ida tree sections Message-ID: <20130809145756.GL20515@mtj.dyndns.org> References: <1375896905-6074-1-git-send-email-kmo@daterainc.com> <1375896905-6074-4-git-send-email-kmo@daterainc.com> <20130807202201.GA28039@mtj.dyndns.org> <20130807205117.GC11612@kmo-pixel> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130807205117.GC11612@kmo-pixel> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 940 Lines: 24 Hello, On Wed, Aug 07, 2013 at 01:51:17PM -0700, Kent Overstreet wrote: > + * So if the max section size is 64k, that's ~4096 sections, with 8 byte > + * pointers that's a little over 32k for the pointers to sections. > + * > + * That means max size sections are order 4 page allocations. Order 4 allocations for common data structure doesn't really sound like a good idea to me. It's gonna work fine on relatively large machines but suck on mobile / small embedded devices, many of which are still struggling with 32bit address space and compaction may not be enabled. It just doens't make sense to me to impose 64k allocations from low level library function like ida. Thanks. -- tejun -- 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/