From: Sergio Gonzalez Monroy <sergio.gonzalez.monroy@intel.com>
To: "Harris, James R" <james.r.harris@intel.com>,
Thomas Monjalon <thomas.monjalon@6wind.com>,
"users@dpdk.org" <users@dpdk.org>, "dev@dpdk.org" <dev@dpdk.org>,
"Richardson, Bruce" <bruce.richardson@intel.com>
Cc: "Verkamp, Daniel" <daniel.verkamp@intel.com>
Subject: Re: [dpdk-dev] [dpdk-users] rte_zmalloc() returning non-zeroed memory on FreeBSD
Date: Tue, 16 Aug 2016 08:36:43 +0100 [thread overview]
Message-ID: <8b8e180e-a996-ef6e-cbf8-23028a194224@intel.com> (raw)
In-Reply-To: <A35C21583F92CE4D8ADBF9D61694E910216BF49B@FMSMSX105.amr.corp.intel.com>
On 15/08/2016 18:23, Harris, James R wrote:
>
>> -----Original Message-----
>> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Thomas Monjalon
>> Sent: Thursday, August 11, 2016 12:05 AM
>> To: users@dpdk.org; dev@dpdk.org; Gonzalez Monroy, Sergio; Richardson,
>> Bruce
>> Cc: Verkamp, Daniel
>> Subject: Re: [dpdk-dev] [dpdk-users] rte_zmalloc() returning non-zeroed
>> memory on FreeBSD
>>
>> Hi,
>>
>> 2016-08-10 23:30, Verkamp, Daniel:
>>> It seems that with DPDK 16.07, rte_zmalloc() and related functions no
>>> longer return zeroed memory reliably on FreeBSD.
>>>
>>> I notice that commit b78c9175118f7d61022ddc5c62ce54a1bd73cea5 ("mem:
>> do
>>> not zero out memory on zmalloc") removed the explicit memset() that
>> used
>>> to ensure the buffer was zeroed; its log message says:
>>>
>>> "Zeroing out memory on rte_zmalloc_socket is not required anymore since
>>> all allocated memory is already zeroed."
>> On Linux, the memory is zeroed by the kernel.
>> Then the zero value is maintained in the rte_malloc pool by rte_free.
>>
>>> However, I don't see how this is guaranteed (at least for FreeBSD), and
>>> it is not true in practice. I've attached a minimized reproducer program -
>>> running it twice in a row fails reliably for me.
>>>
>>> Is there a missing step in FreeBSD, or is it a more general problem for
>>> other platforms?
>> I guess the initial value from the kernel has been verified only on Linux.
>> We could re-add a memset for FreeBSD.
> The problem is that the FreeBSD contigmem driver does not re-zero the huge
> pages each time they are mmap'd - they are only zeroed when contigmem
> initially loads. I will push a patch for this shortly.
So that is the case where we run the app more than once, right?
I missed that, I only ran it once.
Sergio
next prev parent reply other threads:[~2016-08-16 7:37 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1470871839.40000.48.camel@intel.com>
2016-08-11 7:05 ` Thomas Monjalon
2016-08-15 17:23 ` Harris, James R
2016-08-16 7:36 ` Sergio Gonzalez Monroy [this message]
2016-08-16 22:54 ` Harris, James R
2016-11-03 20:04 Lewis Donzis
2016-11-04 16:38 ` Sergio Gonzalez Monroy
2016-11-04 16:43 ` Lewis Donzis
2016-11-04 20:10 ` Lewis Donzis
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=8b8e180e-a996-ef6e-cbf8-23028a194224@intel.com \
--to=sergio.gonzalez.monroy@intel.com \
--cc=bruce.richardson@intel.com \
--cc=daniel.verkamp@intel.com \
--cc=dev@dpdk.org \
--cc=james.r.harris@intel.com \
--cc=thomas.monjalon@6wind.com \
--cc=users@dpdk.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).