| Message ID | 20160724192713.GB22529@mail-itl (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sun, Jul 24, 2016 at 09:27:13PM +0200, Marek Marczykowski-Górecki wrote: > It is no longer required since xl devd use /dev/xen interface. > How would this unit work when there is no /dev/xen interface? To be precise, we prefer /dev/xen interfaces whenever possible but there is a fallback to /proc/xen. Note that a lot of other unit files have this dependency on proc-xen.mount. I'm inclined to say we should keep this dependency but I'm not sure if I missed some obvious things. > Cc: Ian Jackson <ian.jackson@eu.citrix.com> > Cc: Wei Liu <wei.liu2@citrix.com> > Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> > --- > tools/hotplug/Linux/systemd/xendriverdomain.service.in | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/tools/hotplug/Linux/systemd/xendriverdomain.service.in b/tools/hotplug/Linux/systemd/xendriverdomain.service.in > index 0afb54d..a100309 100644 > --- a/tools/hotplug/Linux/systemd/xendriverdomain.service.in > +++ b/tools/hotplug/Linux/systemd/xendriverdomain.service.in > @@ -1,7 +1,5 @@ > [Unit] > Description=Xen driver domain device daemon > -Requires=proc-xen.mount > -After=proc-xen.mount > ConditionVirtualization=xen > > [Service] > -- > 2.5.5
On Mon, Jul 25, 2016 at 10:27:47AM +0100, Wei Liu wrote: > On Sun, Jul 24, 2016 at 09:27:13PM +0200, Marek Marczykowski-Górecki wrote: > > It is no longer required since xl devd use /dev/xen interface. > > > > How would this unit work when there is no /dev/xen interface? Does it happen in reality? I thought /proc/xen is deprecated for a long time... > To be precise, we prefer /dev/xen interfaces whenever possible but there > is a fallback to /proc/xen. Note that a lot of other unit files have > this dependency on proc-xen.mount. > > I'm inclined to say we should keep this dependency but I'm not sure if I > missed some obvious things. > > > Cc: Ian Jackson <ian.jackson@eu.citrix.com> > > Cc: Wei Liu <wei.liu2@citrix.com> > > Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> > > --- > > tools/hotplug/Linux/systemd/xendriverdomain.service.in | 2 -- > > 1 file changed, 2 deletions(-) > > > > diff --git a/tools/hotplug/Linux/systemd/xendriverdomain.service.in b/tools/hotplug/Linux/systemd/xendriverdomain.service.in > > index 0afb54d..a100309 100644 > > --- a/tools/hotplug/Linux/systemd/xendriverdomain.service.in > > +++ b/tools/hotplug/Linux/systemd/xendriverdomain.service.in > > @@ -1,7 +1,5 @@ > > [Unit] > > Description=Xen driver domain device daemon > > -Requires=proc-xen.mount > > -After=proc-xen.mount > > ConditionVirtualization=xen > > > > [Service] > > -- > > 2.5.5 > >
On Mon, Jul 25, 2016 at 11:30:32AM +0200, Marek Marczykowski-Górecki wrote: > On Mon, Jul 25, 2016 at 10:27:47AM +0100, Wei Liu wrote: > > On Sun, Jul 24, 2016 at 09:27:13PM +0200, Marek Marczykowski-Górecki wrote: > > > It is no longer required since xl devd use /dev/xen interface. > > > > > > > How would this unit work when there is no /dev/xen interface? > > Does it happen in reality? I thought /proc/xen is deprecated for a long > time... > I can't tell whether it happens in reality or not. I also hope to get rid of deprecated interface but they are here to stay for as long as it takes. I guess the question is, do you have a compelling reason against keeping this dependency? Wei. > > To be precise, we prefer /dev/xen interfaces whenever possible but there > > is a fallback to /proc/xen. Note that a lot of other unit files have > > this dependency on proc-xen.mount. > > > > I'm inclined to say we should keep this dependency but I'm not sure if I > > missed some obvious things. > > > > > Cc: Ian Jackson <ian.jackson@eu.citrix.com> > > > Cc: Wei Liu <wei.liu2@citrix.com> > > > Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> > > > --- > > > tools/hotplug/Linux/systemd/xendriverdomain.service.in | 2 -- > > > 1 file changed, 2 deletions(-) > > > > > > diff --git a/tools/hotplug/Linux/systemd/xendriverdomain.service.in b/tools/hotplug/Linux/systemd/xendriverdomain.service.in > > > index 0afb54d..a100309 100644 > > > --- a/tools/hotplug/Linux/systemd/xendriverdomain.service.in > > > +++ b/tools/hotplug/Linux/systemd/xendriverdomain.service.in > > > @@ -1,7 +1,5 @@ > > > [Unit] > > > Description=Xen driver domain device daemon > > > -Requires=proc-xen.mount > > > -After=proc-xen.mount > > > ConditionVirtualization=xen > > > > > > [Service] > > > -- > > > 2.5.5 > > > > > > -- > Best Regards, > Marek Marczykowski-Górecki > Invisible Things Lab > A: Because it messes up the order in which people normally read text. > Q: Why is top-posting such a bad thing?
On Mon, Jul 25, 2016 at 10:34:21AM +0100, Wei Liu wrote: > On Mon, Jul 25, 2016 at 11:30:32AM +0200, Marek Marczykowski-Górecki wrote: > > On Mon, Jul 25, 2016 at 10:27:47AM +0100, Wei Liu wrote: > > > On Sun, Jul 24, 2016 at 09:27:13PM +0200, Marek Marczykowski-Górecki wrote: > > > > It is no longer required since xl devd use /dev/xen interface. > > > > > > > > > > How would this unit work when there is no /dev/xen interface? > > > > Does it happen in reality? I thought /proc/xen is deprecated for a long > > time... > > > > I can't tell whether it happens in reality or not. I also hope to get > rid of deprecated interface but they are here to stay for as long as it > takes. > > I guess the question is, do you have a compelling reason against keeping > this dependency? Just cleaning up old stuff, so - no.
On 25/07/16 10:34, Wei Liu wrote: > On Mon, Jul 25, 2016 at 11:30:32AM +0200, Marek Marczykowski-Górecki wrote: >> On Mon, Jul 25, 2016 at 10:27:47AM +0100, Wei Liu wrote: >>> On Sun, Jul 24, 2016 at 09:27:13PM +0200, Marek Marczykowski-Górecki wrote: >>>> It is no longer required since xl devd use /dev/xen interface. >>>> >>> How would this unit work when there is no /dev/xen interface? >> Does it happen in reality? I thought /proc/xen is deprecated for a long >> time... It really should be, but isn't. /proc/xen/capabilities and /proc/xen/allsyms (?) don't have any equivalent in /dev/ >> > I can't tell whether it happens in reality or not. I also hope to get > rid of deprecated interface but they are here to stay for as long as it > takes. > > I guess the question is, do you have a compelling reason against keeping > this dependency? We really should be making xenfs deprecated and able to be compiled out of Linux. It is a hangover of the early classic kernels which isn't necessary, and causes subtle/weird failures if it isn't mounted. ~Andrew
On Mon, Jul 25, 2016 at 10:45:54AM +0100, Andrew Cooper wrote: > On 25/07/16 10:34, Wei Liu wrote: > > On Mon, Jul 25, 2016 at 11:30:32AM +0200, Marek Marczykowski-Górecki wrote: > >> On Mon, Jul 25, 2016 at 10:27:47AM +0100, Wei Liu wrote: > >>> On Sun, Jul 24, 2016 at 09:27:13PM +0200, Marek Marczykowski-Górecki wrote: > >>>> It is no longer required since xl devd use /dev/xen interface. > >>>> > >>> How would this unit work when there is no /dev/xen interface? > >> Does it happen in reality? I thought /proc/xen is deprecated for a long > >> time... > > It really should be, but isn't. > > /proc/xen/capabilities and /proc/xen/allsyms (?) don't have any > equivalent in /dev/ > > >> > > I can't tell whether it happens in reality or not. I also hope to get > > rid of deprecated interface but they are here to stay for as long as it > > takes. > > > > I guess the question is, do you have a compelling reason against keeping > > this dependency? > > We really should be making xenfs deprecated and able to be compiled out > of Linux. It is a hangover of the early classic kernels which isn't > necessary, and causes subtle/weird failures if it isn't mounted. > +1 from me of course! When the kernel is ready, I shall remove the fallback in libraries and then we can remove all references to proc-xen.mount and even proc-xen.mount itself. Wei. > ~Andrew
diff --git a/tools/hotplug/Linux/systemd/xendriverdomain.service.in b/tools/hotplug/Linux/systemd/xendriverdomain.service.in index 0afb54d..a100309 100644 --- a/tools/hotplug/Linux/systemd/xendriverdomain.service.in +++ b/tools/hotplug/Linux/systemd/xendriverdomain.service.in @@ -1,7 +1,5 @@ [Unit] Description=Xen driver domain device daemon -Requires=proc-xen.mount -After=proc-xen.mount ConditionVirtualization=xen [Service]
It is no longer required since xl devd use /dev/xen interface. Cc: Ian Jackson <ian.jackson@eu.citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> --- tools/hotplug/Linux/systemd/xendriverdomain.service.in | 2 -- 1 file changed, 2 deletions(-)