From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Burakov, Anatoly" Subject: Re: [PATCH] doc: add known issue of rte abort on FreeBSD Date: Mon, 21 May 2018 10:28:25 +0100 Message-ID: <5773776c-5896-1dae-740a-0ee01993daaf@intel.com> References: <1526653438-13256-1-git-send-email-reshma.pattan@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: anaotoly.burakov@intel.com, john.mcnamara@intel.com To: Reshma Pattan , dev@dpdk.org Return-path: Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by dpdk.org (Postfix) with ESMTP id 4176CAAD3 for ; Mon, 21 May 2018 11:28:31 +0200 (CEST) In-Reply-To: <1526653438-13256-1-git-send-email-reshma.pattan@intel.com> Content-Language: en-US List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 18-May-18 3:23 PM, Reshma Pattan wrote: > Added known issue of rte_abort taking a long time > on FreeBSD due to recent memory subsystem rework. > > Signed-off-by: Reshma Pattan > --- > doc/guides/rel_notes/release_18_05.rst | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > > diff --git a/doc/guides/rel_notes/release_18_05.rst b/doc/guides/rel_notes/release_18_05.rst > index 3dcb62538..c01781956 100644 > --- a/doc/guides/rel_notes/release_18_05.rst > +++ b/doc/guides/rel_notes/release_18_05.rst > @@ -485,6 +485,21 @@ Known Issues > dpdk-pdump example and any other applications using librte_pdump, cannot work > with older version DPDK primary applications. > > +* **rte_abort takes a long time on FreeBSD due to memory subsytsem rework.** > + > + With the recent memory subsystem changes, DPDK processes now allocate a large > + area of virtual memory address space. During rte_abort FreeBSD will dump the > + contents of the whole reserved memory range, not just the used portion, to a > + core dump file. Write this large core file can take a significant amount of > + time, causing processes to appear hung on the system. > + > + The work around for the issue is to set the system resource limits for core > + dumps before running any tests e.g."limit coredumpsize 0". This will > + effectively disable core dumps on FreeBSD. If they are not to be completely > + disabled, a suitable limit, e.g. 1G might be specified instead of 0. This > + needs to be run per-shell session, or before every test run. This change > + can also be made persistent by adding "kern.coredump=0" to /etc/sysctl.conf > + > > Shared Library Versions > ----------------------- > The explanation is slightly wrong. The slowdown was there before memory rework - FreeBSD apparently dumps entire memory contents, including contigmem pages and anonymous pages. It's just that previously, we didn't preallocate so much memory, so it took ~5 seconds instead of minutes because it wasn't trying to dump 128 gigabytes of VA space. Otherwise, Acked-by: Anatoly Burakov -- Thanks, Anatoly