From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergio Gonzalez Monroy Subject: Re: [PATCH] mempool: fix local cache initialization Date: Thu, 9 Jun 2016 08:57:02 +0100 Message-ID: <1cafd17e-ffe1-83cc-e745-d3dedc5d44cf@intel.com> References: <1465398627-35022-1-git-send-email-sergio.gonzalez.monroy@intel.com> <57586EAC.7090304@6wind.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit To: Olivier Matz , dev@dpdk.org Return-path: Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by dpdk.org (Postfix) with ESMTP id 61B33BE7C for ; Thu, 9 Jun 2016 09:57:22 +0200 (CEST) In-Reply-To: <57586EAC.7090304@6wind.com> List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Hi Olivier, On 08/06/2016 20:14, Olivier Matz wrote: > Hi Sergio, > > Good catch, thanks. The patch looks ok, just few comments > on the commit log: > > On 06/08/2016 05:10 PM, Sergio Gonzalez Monroy wrote: >> The mempool local cache is not being initialize properly leading to > 'initialize' -> 'initialized' ? > and maybe 'is not being' -> 'was not' ? > >> undefined behavior in cases where the allocated memory was used and left >> with data. >> >> Fixes: af75078fece3 ("first public release") > I think it fixes this one instead: > > 213af31e0960 ("mempool: reduce structure size if no cache needed") Fair enough, I thought the issue was there as we never initialized/zeroed the local cache on mempool creation. Usually we would have allocated all mempools on init (or close) and that would be it (initially all memory would be zeroed), but I think you could still manage to reproduce the problem if somehow you where to do something like: rte_malloc(), rte_free(), rte_mempool_create() and the memory was the one we got with malloc and never gets zeroed again. Sergio