DPDK patches and discussions
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From: Stephen Hemminger <stephen@networkplumber.org>
To: "Xie, Huawei" <huawei.xie@intel.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [RFC PATCH 2/2] lib/librte_eal: Remove	unnecessary hugepage zero-filling
Date: Wed, 18 Nov 2015 08:00:13 -0800	[thread overview]
Message-ID: <20151118080013.3cad8f5b@samsung9> (raw)
In-Reply-To: <C37D651A908B024F974696C65296B57B4B198CF8@SHSMSX101.ccr.corp.intel.com>

On Wed, 18 Nov 2015 12:07:54 +0000
"Xie, Huawei" <huawei.xie@intel.com> wrote:

> >>> The kernel fills new allocated (huge) pages with zeros.
> >>> DPDK just has to touch the pages to trigger the allocation.  
> I think we shouldn't reply on the assumption that kernel has zeroed the
> memory. Kernel zeroes the memory mostly to avoid information leakage.It
> could also achieve this by setting each bit to 1.
> What we indeed need to check is later DPDK initialization code doesn't
> assume the memory has been zeroed. Otherwise zero only that part of the
> memory. Does this makes sense?

If all new pages are zero, why does DPDK have to pre-touch the pages
at all?

I thought there as some optimization to initialize hugepages since
Oracle has same problem with their Shared Global Area which was why
hugpages were invented anyway

  reply	other threads:[~2015-11-18 16:00 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-11-18  3:27 [dpdk-dev] [RFC PATCH 0/2] Reduce DPDK initialization time Zhihong Wang
2015-11-18  3:27 ` [dpdk-dev] [RFC PATCH 1/2] lib/librte_eal: Reduce timer " Zhihong Wang
2015-11-18  3:27 ` [dpdk-dev] [RFC PATCH 2/2] lib/librte_eal: Remove unnecessary hugepage zero-filling Zhihong Wang
2015-11-18 10:39   ` Mcnamara, John
2015-11-18 10:44     ` Wang, Zhihong
2015-11-18 12:07       ` Xie, Huawei
2015-11-18 16:00         ` Stephen Hemminger [this message]
2015-11-18 16:13           ` Richardson, Bruce
2015-11-18 19:09             ` Stephen Hemminger
2015-11-19  2:15               ` Wang, Zhihong
2015-11-19  6:04                 ` Xie, Huawei
2015-11-19  6:32                   ` Wang, Zhihong
2015-11-19  9:18                     ` Sergio Gonzalez Monroy
2015-11-23  2:54                     ` Xie, Huawei
2015-11-23 10:18                       ` Bruce Richardson
2015-11-20 12:15               ` Bruce Richardson
2015-11-19  3:54         ` Wang, Zhihong
2015-11-19  6:09           ` Xie, Huawei
2015-11-19  9:14         ` Sergio Gonzalez Monroy
2015-11-23  3:46           ` Xie, Huawei
2015-11-23  4:07             ` Stephen Hemminger
2015-11-23  5:05               ` Xie, Huawei
2015-11-23  6:52                 ` Stephen Hemminger
2015-11-25 18:24                   ` Xie, Huawei
2015-12-24  8:34 ` [dpdk-dev] [RFC PATCH 0/2] Reduce DPDK initialization time Qiu, Michael

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