Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932442Ab1C3MWK (ORCPT ); Wed, 30 Mar 2011 08:22:10 -0400 Received: from mail-fx0-f46.google.com ([209.85.161.46]:36029 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754883Ab1C3MWI (ORCPT ); Wed, 30 Mar 2011 08:22:08 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:from:to:cc:in-reply-to:references:content-type:date :message-id:mime-version:x-mailer:content-transfer-encoding; b=KZDSgMuf7SGJm0O86qU8OtMp9xeOwcqrQfnYfiSNUCrRVPezFGstXWWeWg8r3WcrcA H9AOp2Ol+E+0R7P/0aLEa0n9FcOprwnMKwO20ejk72Qn+Uthr/Q8zj2/t2Joa1PXcERZ gI68pO/pK0WQly5tUFL21taqzccsr5Oo40MJM= Subject: Re: kmemleak for MIPS From: Eric Dumazet To: Daniel Baluta Cc: Maxin John , naveen yadav , linux-mips@linux-mips.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Catalin Marinas In-Reply-To: References: <9bde694e1003020554p7c8ff3c2o4ae7cb5d501d1ab9@mail.gmail.com> <1300960540.32158.13.camel@e102109-lin.cambridge.arm.com> <1301395206.583.53.camel@e102109-lin.cambridge.arm.com> <1301399454.583.66.camel@e102109-lin.cambridge.arm.com> <1301476505.29074.47.camel@e102109-lin.cambridge.arm.com> Content-Type: text/plain; charset="UTF-8" Date: Wed, 30 Mar 2011 14:22:00 +0200 Message-ID: <1301487720.3283.32.camel@edumazet-laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1548 Lines: 46 Le mercredi 30 mars 2011 à 14:24 +0300, Daniel Baluta a écrit : > We have: > > > UDP hash table entries: 128 (order: 0, 4096 bytes) > > CONFIG_BASE_SMALL=0 > > udp_table_init looks like: > > if (!CONFIG_BASE_SMALL) > table->hash = alloc_large_system_hash(name, .. &table->mask); > /* > * Make sure hash table has the minimum size > */ > > Since CONFIG_BASE_SMALL is 0, we are allocating the hash using > alloc_large_system > Then: > if (CONFIG_BASE_SMALL || table->mask < UDP_HTABLE_SIZE_MIN - 1) { > table->hash = kmalloc(); > > table->mask is 127, and UDP_HTABLE_SIZE_MIN is 256, so we are allocating again > table->hash without freeing already allocated memory. > > We could free table->hash, before allocating the memory with kmalloc. > I don't fully understand the condition table->mask < UDP_HTABLE_SIZE_MIN - 1. > > Eric? There is nothing special. UDP algo needs a minimum hash table that alloc_large_system_hash() was not able to provide (???) As you spotted, there is no free_large-system_hash(), so we 'leak' the small hash table. If machine has not enough memory to provide such a small hash table, I suggest using CONFIG_BASE_SMALL, since : #define UDP_HTABLE_SIZE_MIN (CONFIG_BASE_SMALL ? 128 : 256) -- 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/