| Message ID | 153299242656.14411.14216251294160965283.stgit@gimli.home (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Balloon inhibit enhancements, vfio restriction | expand |
On 31.07.2018 01:13, Alex Williamson wrote: > A simple true/false internal state does not allow multiple users. Fix > this within the existing interface by converting to a counter, so long > as the counter is elevated, ballooning is inhibited. > Not sure if "nested" is really the right term here. It is really multiple users. anyhow Reviewed-by: David Hildenbrand <david@redhat.com> > Signed-off-by: Alex Williamson <alex.williamson@redhat.com> > --- > balloon.c | 13 ++++++++++--- > 1 file changed, 10 insertions(+), 3 deletions(-) > > diff --git a/balloon.c b/balloon.c > index 6bf0a9681377..931987983858 100644 > --- a/balloon.c > +++ b/balloon.c > @@ -26,6 +26,7 @@ > > #include "qemu/osdep.h" > #include "qemu-common.h" > +#include "qemu/atomic.h" > #include "exec/cpu-common.h" > #include "sysemu/kvm.h" > #include "sysemu/balloon.h" > @@ -37,16 +38,22 @@ > static QEMUBalloonEvent *balloon_event_fn; > static QEMUBalloonStatus *balloon_stat_fn; > static void *balloon_opaque; > -static bool balloon_inhibited; > +static int balloon_inhibit_count; > > bool qemu_balloon_is_inhibited(void) > { > - return balloon_inhibited; > + return atomic_read(&balloon_inhibit_count) > 0; > } > > void qemu_balloon_inhibit(bool state) > { > - balloon_inhibited = state; > + if (state) { > + atomic_inc(&balloon_inhibit_count); > + } else { > + atomic_dec(&balloon_inhibit_count); > + } > + > + assert(atomic_read(&balloon_inhibit_count) >= 0); > } > > static bool have_balloon(Error **errp) >
On Mon, Jul 30, 2018 at 05:13:46PM -0600, Alex Williamson wrote: > A simple true/false internal state does not allow multiple users. Fix > this within the existing interface by converting to a counter, so long > as the counter is elevated, ballooning is inhibited. > > Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com> Regards,
On Mon, 30 Jul 2018 17:13:46 -0600 Alex Williamson <alex.williamson@redhat.com> wrote: > A simple true/false internal state does not allow multiple users. Fix > this within the existing interface by converting to a counter, so long > as the counter is elevated, ballooning is inhibited. > > Signed-off-by: Alex Williamson <alex.williamson@redhat.com> > --- > balloon.c | 13 ++++++++++--- > 1 file changed, 10 insertions(+), 3 deletions(-) Reviewed-by: Cornelia Huck <cohuck@redhat.com>
diff --git a/balloon.c b/balloon.c index 6bf0a9681377..931987983858 100644 --- a/balloon.c +++ b/balloon.c @@ -26,6 +26,7 @@ #include "qemu/osdep.h" #include "qemu-common.h" +#include "qemu/atomic.h" #include "exec/cpu-common.h" #include "sysemu/kvm.h" #include "sysemu/balloon.h" @@ -37,16 +38,22 @@ static QEMUBalloonEvent *balloon_event_fn; static QEMUBalloonStatus *balloon_stat_fn; static void *balloon_opaque; -static bool balloon_inhibited; +static int balloon_inhibit_count; bool qemu_balloon_is_inhibited(void) { - return balloon_inhibited; + return atomic_read(&balloon_inhibit_count) > 0; } void qemu_balloon_inhibit(bool state) { - balloon_inhibited = state; + if (state) { + atomic_inc(&balloon_inhibit_count); + } else { + atomic_dec(&balloon_inhibit_count); + } + + assert(atomic_read(&balloon_inhibit_count) >= 0); } static bool have_balloon(Error **errp)
A simple true/false internal state does not allow multiple users. Fix this within the existing interface by converting to a counter, so long as the counter is elevated, ballooning is inhibited. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> --- balloon.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-)