From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.droids-corp.org (zoll.droids-corp.org [94.23.50.67]) by dpdk.org (Postfix) with ESMTP id 39C852BCE for ; Thu, 10 Mar 2016 09:37:55 +0100 (CET) Received: from was59-1-82-226-113-214.fbx.proxad.net ([82.226.113.214] helo=[192.168.0.10]) by mail.droids-corp.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.84) (envelope-from ) id 1adw7z-0006qi-Hr; Thu, 10 Mar 2016 09:39:28 +0100 To: Stephen Hemminger , dev@dpdk.org References: <1457557926-4056-1-git-send-email-stephen@networkplumber.org> From: Olivier MATZ Message-ID: <56E1325C.2030206@6wind.com> Date: Thu, 10 Mar 2016 09:37:48 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Icedove/38.6.0 MIME-Version: 1.0 In-Reply-To: <1457557926-4056-1-git-send-email-stephen@networkplumber.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH, v2] mempool: avoid memory waste with large pagesize X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 10 Mar 2016 08:37:55 -0000 Hello, On 03/09/2016 10:12 PM, Stephen Hemminger wrote: > If page size is large (like 64K on ARM) and object size is small > then don't waste lots of memory by rounding up to page size. > Instead, round up so that 1 or more objects all fit in a page. > > This preserves the requirement that an object must not a page > or virt2phys would break, and makes sure 62K is not wasted per mbuf. > > Also, fix invalid use of printf (versus log) for error reporting. > > Signed-off-by: Stephen Hemminger > --- > v2 - fix trailer_size calculation, and replace printf with log > > lib/librte_mempool/rte_mempool.c | 23 ++++++++++++++--------- > 1 file changed, 14 insertions(+), 9 deletions(-) > > diff --git a/lib/librte_mempool/rte_mempool.c b/lib/librte_mempool/rte_mempool.c > index f8781e1..ff08a1a 100644 > --- a/lib/librte_mempool/rte_mempool.c > +++ b/lib/librte_mempool/rte_mempool.c > @@ -300,18 +300,23 @@ rte_mempool_calc_obj_size(uint32_t elt_size, uint32_t flags, > if (! rte_eal_has_hugepages()) { > /* > * compute trailer size so that pool elements fit exactly in > - * a standard page > + * a standard page. If elements are smaller than a page > + * then allow multiple elements per page > */ > - int page_size = getpagesize(); > - int new_size = page_size - sz->header_size - sz->elt_size; > - if (new_size < 0 || (unsigned int)new_size < sz->trailer_size) { > - printf("When hugepages are disabled, pool objects " > - "can't exceed PAGE_SIZE: %d + %d + %d > %d\n", > - sz->header_size, sz->elt_size, sz->trailer_size, > - page_size); > + unsigned new_size, orig_size, page_size; > + > + page_size = getpagesize(); > + orig_size = sz->header_size + sz->elt_size; > + new_size = rte_align32pow2(orig_size); > + if (new_size > page_size) { > + RTE_LOG(ERR, MEMPOOL, > + "When hugepages are disabled, pool objects " > + "can't exceed PAGE_SIZE: %u + %u + %u > %u\n", > + sz->header_size, sz->elt_size, sz->trailer_size, > + page_size); > return 0; > } > - sz->trailer_size = new_size; > + sz->trailer_size = new_size - orig_size; > } > > /* this is the size of an object, including header and trailer */ > It still does not work. When CONFIG_RTE_LIBRTE_MEMPOOL_DEBUG=y: mp = rte_mempool_create("test", 128, 64, 0, 0, NULL, NULL, NULL, NULL, SOCKET_ID_ANY, 0); rte_mempool_dump(stdout, mp); populated_size=128 header_size=64 elt_size=64 trailer_size=64 total_obj_size=192 Regards, Olivier