From: "Wang, Zhihong" <zhihong.wang@intel.com>
To: Thomas Monjalon <thomas.monjalon@6wind.com>,
Stephen Hemminger <stephen@networkplumber.org>
Cc: "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH 2/2] lib/librte_eal: Remove unnecessary hugepage zero-filling
Date: Wed, 25 Nov 2015 01:59:12 +0000 [thread overview]
Message-ID: <8F6C2BD409508844A0EFC19955BE0941835ADD@SHSMSX152.ccr.corp.intel.com> (raw)
In-Reply-To: <3179262.cyHqZdDHPg@xps13>
> -----Original Message-----
> From: Thomas Monjalon [mailto:thomas.monjalon@6wind.com]
> Sent: Wednesday, November 25, 2015 7:04 AM
> To: Stephen Hemminger <stephen@networkplumber.org>
> Cc: Wang, Zhihong <zhihong.wang@intel.com>; dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH 2/2] lib/librte_eal: Remove unnecessary
> hugepage zero-filling
>
> 2015-11-24 14:44, Stephen Hemminger:
> > On Tue, 24 Nov 2015 22:13:28 +0100
> > Thomas Monjalon <thomas.monjalon@6wind.com> wrote:
> >
> > > 2015-11-22 18:28, Stephen Hemminger:
> > > > On Sun, 22 Nov 2015 14:13:35 -0500 Zhihong Wang
> > > > <zhihong.wang@intel.com> wrote:
> > > >
> > > > > The kernel fills new allocated (huge) pages with zeros.
> > > > > DPDK just has to populate page tables to trigger the allocation.
> > > > >
> > > > > Signed-off-by: Zhihong Wang <zhihong.wang@intel.com>
> > > >
> > > > Nice, especially on slow machines or with large memory.
> > > >
> > > > Acked-by: Stephen Hemminger <stephen@networkplumber.org>
> > >
> > > Yes very nice.
> > > I think it's too late to integrate this change which can have some
> > > unpredictable side effects.
> > > Do you agree to wait for 2.3?
> >
> > What side effects? Either it is zero or it is not.
> > Only some broken architecture would have an issue.
>
> I mean it changes the memory allocator behaviour. It's not something we want to
> discover a new bug just before the release.
> This kind of important change must be integrated at the beginning of the release
> cycle.
> I'm asking for opinions because it would be really nice to have.
Literally this patch doesn't change anything, it just keeps DPDK from zero-filling pages again which have just been zero-filled.
It would be nice to have this patch in DPDK 2.2 since it can reduce the startup time nearly by half for hugepage cases.
But I understand longer merge/test window make it safer for a release.
It makes sense either way.
next prev parent reply other threads:[~2015-11-25 1:59 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-22 19:13 [dpdk-dev] [PATCH 0/2] Reduce DPDK initialization time Zhihong Wang
2015-11-22 19:13 ` [dpdk-dev] [PATCH 1/2] lib/librte_eal: Reduce timer " Zhihong Wang
2015-11-22 19:13 ` [dpdk-dev] [PATCH 2/2] lib/librte_eal: Remove unnecessary hugepage zero-filling Zhihong Wang
2015-11-23 2:28 ` Stephen Hemminger
2015-11-24 21:13 ` Thomas Monjalon
2015-11-24 22:44 ` Stephen Hemminger
2015-11-24 23:04 ` Thomas Monjalon
2015-11-25 1:57 ` Yuanhan Liu
2015-11-25 1:59 ` Wang, Zhihong [this message]
2016-01-21 14:59 ` [dpdk-dev] [PATCH 0/2] Reduce DPDK initialization time Thomas Monjalon
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