Re: [dpdk-stable] patch 'mem: mark pages as not accessed when reserving VA' has been queued to stable release 19.11.3

[Luca Boccassi <bluca@debian.org>]

On Tue, 2020-06-09 at 15:14 +0100, Luca Boccassi wrote:
> On Tue, 2020-06-09 at 14:45 +0100, Kevin Traynor wrote:
> > On 19/05/2020 13:53, luca.boccassi@gmail.com wrote:
> > > Hi,
> > > 
> > > FYI, your patch has been queued to stable release 19.11.3
> > > 
> > > Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
> > > It will be pushed if I get no objections before 05/21/20. So please
> > > shout if anyone has objections.
> > > 
> > > Also note that after the patch there's a diff of the upstream commit vs the
> > > patch applied to the branch. This will indicate if there was any rebasing
> > > needed to apply to the stable branch. If there were code changes for rebasing
> > > (ie: not only metadata diffs), please double check that the rebase was
> > > correctly done.
> > > 
> > > Thanks.
> > > 
> > > Luca Boccassi
> > > 
> > > ---
> > > From d0e456e9b1af8594ed22382e33bc6e1d5acec994 Mon Sep 17 00:00:00 2001
> > > From: David Marchand <david.marchand@redhat.com>
> > > Date: Mon, 9 Mar 2020 15:54:42 +0100
> > > Subject: [PATCH] mem: mark pages as not accessed when reserving VA
> > > 
> > > [ upstream commit 8a4baf06c17a806696fb10aba36fce7471983028 ]
> > > 
> > > When the memory allocator reserves virtual addresses, it still does not
> > > know what they will be used for.
> > > Besides, huge areas are reserved for memory hotplug in multiprocess
> > > setups. But most of the pages are unused in the whole life of the
> > > processes.
> > > 
> > > Change protection mode to PROT_NONE when only reserving VA.
> > > The memory allocator already switches to the right mode when making use
> > > of it.
> > > 
> > > It also has the nice effect of getting those pages skipped by the kernel
> > > when calling mlockall() or when a coredump gets generated.
> > > 
> > 
> > Hi, discussed this patch for 18.11 with David and he pointed out that
> > there is a fix for it on master:
> 
> Uh, I wonder how it got left behind, strange - how critical is it? And
> how safe is it to pick up now, when validation has already started?

Ping - David, what do you think about the above questions?

-- 
Kind regards,
Luca Boccassi