From: Tamas K Lengyel <tamas@tklengyel.com>
To: Jan Beulich <jbeulich@suse.com>
Cc: "Julien Grall" <julien@xen.org>,
"Stefano Stabellini" <sstabellini@kernel.org>,
"Tamas K Lengyel" <tamas.lengyel@intel.com>,
"Wei Liu" <wl@xen.org>,
"Andrew Cooper" <andrew.cooper3@citrix.com>,
"Ian Jackson" <ian.jackson@eu.citrix.com>,
"George Dunlap" <george.dunlap@citrix.com>,
Xen-devel <xen-devel@lists.xenproject.org>,
"Roger Pau Monné" <roger.pau@citrix.com>
Subject: Re: [Xen-devel] [PATCH v12 1/3] xen/mem_sharing: VM forking
Date: Thu, 26 Mar 2020 08:52:50 -0600 [thread overview]
Message-ID: <CABfawhnMPpJJNCj3ttBurt_FcqyK=v=twJ3RVRMAPBQ15g48LA@mail.gmail.com> (raw)
In-Reply-To: <d22bf48d-0f58-3a1e-f5d2-794f0dc846dd@suse.com>
On Thu, Mar 26, 2020 at 6:33 AM Jan Beulich <jbeulich@suse.com> wrote:
>
> On 23.03.2020 18:04, Tamas K Lengyel wrote:
> > --- a/xen/arch/x86/domain.c
> > +++ b/xen/arch/x86/domain.c
> > @@ -2202,6 +2202,17 @@ int domain_relinquish_resources(struct domain *d)
> > ret = relinquish_shared_pages(d);
> > if ( ret )
> > return ret;
> > +
> > + /*
> > + * If the domain is forked, decrement the parent's pause count
> > + * and release the domain.
> > + */
> > + if ( mem_sharing_is_fork(d) )
> > + {
> > + domain_unpause(d->parent);
> > + put_domain(d->parent);
> > + d->parent = NULL;
>
> I think you want to clear the field before putting the reference,
> to make sure possible readers of it won't see it non-NULL when
> the domain is already being cleaned up, or even gone.
Sure.
>
> With this, applicable parts of the change
> Acked-by: Jan Beulich <jbeulich@suse.com>
>
> I'll try to keep an eye on when you and Roger have settled on the
> remaining aspects, to determine when this (probably v13) can be
> committed.
Thanks!
>
> > --- a/xen/include/asm-x86/mem_sharing.h
> > +++ b/xen/include/asm-x86/mem_sharing.h
> > @@ -77,6 +77,14 @@ static inline int mem_sharing_unshare_page(struct domain *d,
> > return rc;
> > }
> >
> > +static inline bool mem_sharing_is_fork(struct domain *d)
>
> const? (then also in the stub further down)
Sure.
Tamas
next prev parent reply other threads:[~2020-03-26 14:53 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-23 17:04 [Xen-devel] [PATCH v12 0/3] VM forking Tamas K Lengyel
2020-03-23 17:04 ` [Xen-devel] [PATCH v12 1/3] xen/mem_sharing: " Tamas K Lengyel
2020-03-25 15:47 ` Roger Pau Monné
2020-03-25 16:04 ` Tamas K Lengyel
2020-03-25 16:16 ` Tamas K Lengyel
2020-03-25 16:34 ` Tamas K Lengyel
2020-03-25 16:42 ` Julien Grall
2020-03-25 16:47 ` Tamas K Lengyel
2020-03-25 16:51 ` Julien Grall
2020-03-25 17:00 ` Tamas K Lengyel
2020-03-25 17:16 ` Roger Pau Monné
2020-03-25 17:47 ` Tamas K Lengyel
2020-03-25 16:54 ` Roger Pau Monné
2020-03-26 7:02 ` Jan Beulich
2020-03-26 8:42 ` Roger Pau Monné
2020-03-26 7:07 ` Jan Beulich
2020-03-26 9:10 ` Roger Pau Monné
2020-03-26 17:01 ` Tamas K Lengyel
2020-03-26 12:33 ` Jan Beulich
2020-03-26 14:52 ` Tamas K Lengyel [this message]
2020-03-23 17:04 ` [Xen-devel] [PATCH v12 2/3] x86/mem_sharing: reset a fork Tamas K Lengyel
2020-03-25 15:52 ` Roger Pau Monné
2020-03-25 15:54 ` Tamas K Lengyel
2020-03-26 10:16 ` Jan Beulich
2020-03-26 14:48 ` Tamas K Lengyel
2020-03-26 14:52 ` Jan Beulich
2020-03-26 14:53 ` Tamas K Lengyel
2020-03-26 23:40 ` Tamas K Lengyel
2020-03-23 17:04 ` [Xen-devel] [PATCH v12 3/3] xen/tools: VM forking toolstack side Tamas K Lengyel
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