search for: doing_io

...hanged, 6 insertions(+), 1 deletion(-) > > diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c > index a5e8530a3391..36252f344660 100644 > --- a/drivers/s390/virtio/virtio_ccw.c > +++ b/drivers/s390/virtio/virtio_ccw.c > @@ -289,6 +289,8 @@ static int doing_io(struct virtio_ccw_device *vcdev, __u32 flag) > return ret; > } > > +DEFINE_MUTEX(vcio_mtx); > + > static int ccw_io_helper(struct virtio_ccw_device *vcdev, > struct ccw1 *ccw, __u32 intparm) > { > @@ -296,6 +298,7 @@ static int ccw_io_helper(struct virtio_ccw_...

...ing about how its actually rare for the call to sleep. So occasional sleeps inside a wait_event() are ok-ish, we'll just get to go around once more. But once you consistently sleep inside a wait_event() things go a bit funny. So for instance; if in ccw_io_helper() we expect that wait_event(, !doing_io()) to be (mostly) true on first go, then we'll never get into __wait_event() and ->state won't actually be mucked about with. The thing to avoid is not actually sleeping (much) but setting TASK_RUNNING and turning the entire thing into a giant poll loop.

...ing about how its actually rare for the call to sleep. So occasional sleeps inside a wait_event() are ok-ish, we'll just get to go around once more. But once you consistently sleep inside a wait_event() things go a bit funny. So for instance; if in ccw_io_helper() we expect that wait_event(, !doing_io()) to be (mostly) true on first go, then we'll never get into __wait_event() and ->state won't actually be mucked about with. The thing to avoid is not actually sleeping (much) but setting TASK_RUNNING and turning the entire thing into a giant poll loop.

On Thu, Feb 26, 2015 at 11:50:42AM +1030, Rusty Russell wrote: > Thomas Huth <thuth at linux.vnet.ibm.com> writes: > > Hi all, > > > > with the recent kernel 3.19, I get a kernel warning when I start my > > KVM guest on s390 with virtio balloon enabled: > > The deeper problem is that virtio_ccw_get_config just silently fails on > OOM. > > Neither

On Thu, Feb 26, 2015 at 11:50:42AM +1030, Rusty Russell wrote: > Thomas Huth <thuth at linux.vnet.ibm.com> writes: > > Hi all, > > > > with the recent kernel 3.19, I get a kernel warning when I start my > > KVM guest on s390 with virtio balloon enabled: > > The deeper problem is that virtio_ccw_get_config just silently fails on > OOM. > > Neither

The following changes since commit 8c0f9f5b309d627182d5da72a69246f58bde1026: Revert "uapi/linux/keyctl.h: don't use C++ reserved keyword as a struct member name" (2018-09-25 13:28:58 +0200) are available in the Git repository at: git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux.git tags/virtio-ccw-20180926 for you to fetch changes up to

Hi Rusty! There are a bunch of (mostly virtio 1.0 related) fixes for virtio that need to go into 4.0 I think. virtio_blk: typo fix virtio_blk: fix comment for virtio 1.0 virtio_console: init work unconditionally virtio_console: avoid config access from irq virtio_balloon: set DRIVER_OK before using device seem ready? virtio_mmio: generation support virtio_mmio: fix endian-ness for mmio

Hi Rusty! There are a bunch of (mostly virtio 1.0 related) fixes for virtio that need to go into 4.0 I think. virtio_blk: typo fix virtio_blk: fix comment for virtio 1.0 virtio_console: init work unconditionally virtio_console: avoid config access from irq virtio_balloon: set DRIVER_OK before using device seem ready? virtio_mmio: generation support virtio_mmio: fix endian-ness for mmio

...vcdev->err = 0; vcdev->curr_io |= flag; } spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags); cpu_relax(); } while (ret == -EBUSY); wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0); return ret ? ret : vcdev->err; } > and this > + * isn't a fast path in any sense. > + */ > + sched_annotate_sleep(); > + > wait_event_interruptible(vb->config_change, > (diff = towards_target(vb)) != 0 > || vb-&...

...vcdev->err = 0; vcdev->curr_io |= flag; } spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags); cpu_relax(); } while (ret == -EBUSY); wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0); return ret ? ret : vcdev->err; } > and this > + * isn't a fast path in any sense. > + */ > + sched_annotate_sleep(); > + > wait_event_interruptible(vb->config_change, > (diff = towards_target(vb)) != 0 > || vb-&...

On Mon, Mar 02, 2015 at 10:37:26AM +1030, Rusty Russell wrote: > Thomas Huth <thuth at linux.vnet.ibm.com> writes: > > On Thu, 26 Feb 2015 11:50:42 +1030 > > Rusty Russell <rusty at rustcorp.com.au> wrote: > > > >> Thomas Huth <thuth at linux.vnet.ibm.com> writes: > >> > Hi all, > >> > > >> > with the recent

On Mon, Mar 02, 2015 at 10:37:26AM +1030, Rusty Russell wrote: > Thomas Huth <thuth at linux.vnet.ibm.com> writes: > > On Thu, 26 Feb 2015 11:50:42 +1030 > > Rusty Russell <rusty at rustcorp.com.au> wrote: > > > >> Thomas Huth <thuth at linux.vnet.ibm.com> writes: > >> > Hi all, > >> > > >> > with the recent

Hi, here's the guest driver support for adapter interrupts in virtio-ccw. We use one summary indicator per page of indicators. For each device, we try to find a space in an indicator where all of its virtqueues fit. Locking probably needs some more love, but it seems to work fine so far. Cornelia Huck (2): KVM: s390: virtio-ccw: Handle command rejects. KVM: s390: virtio-ccw adapter

Hi, here's the guest driver support for adapter interrupts in virtio-ccw. We use one summary indicator per page of indicators. For each device, we try to find a space in an indicator where all of its virtqueues fit. Locking probably needs some more love, but it seems to work fine so far. Cornelia Huck (2): KVM: s390: virtio-ccw: Handle command rejects. KVM: s390: virtio-ccw adapter

Hi, next version of the guest exploitation of virtio-ccw adapter interrupts. Changes from the last version: - adapt to latest kvm-next - changed housekeeping for indicator locations: we now use cacheline-sized and aligned areas - minor tweaks Cornelia Huck (2): KVM: s390: virtio-ccw: Handle command rejects. KVM: s390: virtio-ccw adapter interrupt support. arch/s390/include/asm/irq.h

Hi, next version of the guest exploitation of virtio-ccw adapter interrupts. Changes from the last version: - adapt to latest kvm-next - changed housekeeping for indicator locations: we now use cacheline-sized and aligned areas - minor tweaks Cornelia Huck (2): KVM: s390: virtio-ccw: Handle command rejects. KVM: s390: virtio-ccw adapter interrupt support. arch/s390/include/asm/irq.h