This series replaces the existing paravirtualized spinlock mechanism
with a paravirtualized ticketlock mechanism. The series provides
implementation for both Xen and KVM.
Changes in V11:
- use safe_halt in lock_spinning path to avoid potential problem
in case of irq_handlers taking lock in
x86/spinlock: Replace pv spinlocks with pv ticketlocks
From: Jeremy Fitzhardinge jer...@goop.org
Rather than outright replacing the entire spinlock implementation in
order to paravirtualize it, keep the ticket lock implementation but add
a couple of pvops hooks on the slow patch (long spin on
x86/ticketlock: Don't inline _spin_unlock when using paravirt spinlocks
From: Raghavendra K T raghavendra...@linux.vnet.ibm.com
The code size expands somewhat, and its better to just call
a function rather than inline it.
Thanks Jeremy for original version of ARCH_NOINLINE_SPIN_UNLOCK config
x86/ticketlock: Collapse a layer of functions
From: Jeremy Fitzhardinge jer...@goop.org
Now that the paravirtualization layer doesn't exist at the spinlock
level any more, we can collapse the __ticket_ functions into the arch_
functions.
Signed-off-by: Jeremy Fitzhardinge jer...@goop.org
xen: Defer spinlock setup until boot CPU setup
From: Jeremy Fitzhardinge jer...@goop.org
There's no need to do it at very early init, and doing it there
makes it impossible to use the jump_label machinery.
Signed-off-by: Jeremy Fitzhardinge jer...@goop.org
Reviewed-by: Konrad Rzeszutek Wilk
xen/pvticketlock: Xen implementation for PV ticket locks
From: Jeremy Fitzhardinge jer...@goop.org
Replace the old Xen implementation of PV spinlocks with and implementation
of xen_lock_spinning and xen_unlock_kick.
xen_lock_spinning simply registers the cpu in its entry in lock_waiting,
adds
xen/pvticketlocks: Add xen_nopvspin parameter to disable xen pv ticketlocks
From: Jeremy Fitzhardinge jer...@goop.org
Signed-off-by: Jeremy Fitzhardinge jer...@goop.org
Reviewed-by: Konrad Rzeszutek Wilk konrad.w...@oracle.com
Signed-off-by: Raghavendra K T raghavendra...@linux.vnet.ibm.com
---
x86/pvticketlock: When paravirtualizing ticket locks, increment by 2
From: Jeremy Fitzhardinge jer...@goop.org
Increment ticket head/tails by 2 rather than 1 to leave the LSB free
to store a is in slowpath state bit. This halves the number
of possible CPUs for a given ticket size, but this
x86/pvticketlock: Use callee-save for lock_spinning
From: Jeremy Fitzhardinge jer...@goop.org
Although the lock_spinning calls in the spinlock code are on the
uncommon path, their presence can cause the compiler to generate many
more register save/restores in the function pre/postamble, which is
jump_label: Split jumplabel ratelimit
From: Andrew Jones drjo...@redhat.com
Commit b202952075f62603bea9bfb6ebc6b0420db11949 (perf, core: Rate limit
perf_sched_events jump_label patching) introduced rate limiting
for jump label disabling. The changes were made in the jump label code
in order to
x86/ticketlock: Add slowpath logic
From: Jeremy Fitzhardinge jer...@goop.org
Maintain a flag in the LSB of the ticket lock tail which indicates
whether anyone is in the lock slowpath and may need kicking when
the current holder unlocks. The flags are set when the first locker
enters the
kvm hypervisor : Add a hypercall to KVM hypervisor to support pv-ticketlocks
From: Srivatsa Vaddagiri va...@linux.vnet.ibm.com
kvm_hc_kick_cpu allows the calling vcpu to kick another vcpu out of halt state.
the presence of these hypercalls is indicated to guest via
kvm_feature_pv_unhalt.
kvm : Fold pv_unhalt flag into GET_MP_STATE ioctl to aid migration
From: Raghavendra K T raghavendra...@linux.vnet.ibm.com
During migration, any vcpu that got kicked but did not become runnable
(still in halted state) should be runnable after migration.
Signed-off-by: Raghavendra K T
xen/pvticketlock: Allow interrupts to be enabled while blocking
From: Jeremy Fitzhardinge jer...@goop.org
If interrupts were enabled when taking the spinlock, we can leave them
enabled while blocking to get the lock.
If we can enable interrupts while waiting for the lock to become
available,
kvm guest : Add configuration support to enable debug information for KVM Guests
From: Srivatsa Vaddagiri va...@linux.vnet.ibm.com
Signed-off-by: Srivatsa Vaddagiri va...@linux.vnet.ibm.com
Signed-off-by: Suzuki Poulose suz...@in.ibm.com
Signed-off-by: Raghavendra K T
kvm : Paravirtual ticketlocks support for linux guests running on KVM hypervisor
From: Srivatsa Vaddagiri va...@linux.vnet.ibm.com
During smp_boot_cpus paravirtualied KVM guest detects if the hypervisor has
required feature (KVM_FEATURE_PV_UNHALT) to support pv-ticketlocks. If so,
support for
kvm hypervisor: Add directed yield in vcpu block path
From: Raghavendra K T raghavendra...@linux.vnet.ibm.com
We use the improved PLE handler logic in vcpu block patch for
scheduling rather than plain schedule, so that we can make
intelligent decisions.
Signed-off-by: Raghavendra K T
kvm hypervisor: Simplify kvm_for_each_vcpu with kvm_irq_delivery_to_apic
From: Raghavendra K T raghavendra...@linux.vnet.ibm.com
Note that we are using APIC_DM_REMRD which has reserved usage.
In future if APIC_DM_REMRD usage is standardized, then we should
find some other way or go back to old
Documentation/kvm : Add documentation on Hypercalls and features used for PV
spinlock
From: Raghavendra K T raghavendra...@linux.vnet.ibm.com
KVM_HC_KICK_CPU hypercall added to wakeup halted vcpu in paravirtual spinlock
enabled guest.
KVM_FEATURE_PV_UNHALT enables guest to check whether pv
On 07/19/2013 07:21 PM, Amit Shah wrote:
Hello,
This series fixes a few bugs and races with port unplug and the
various file operations: read(), write(), close() and poll().
There still might be more races lurking, but testing this series looks
good to at least solve the easily-triggerable
On (Mon) 22 Jul 2013 [13:00:43], Yoshihiro YUNOMAE wrote:
Hi,
This patch set fixes two bugs of splice_write in the virtio-console driver.
[BUG1] Although pipe-nrbufs is empty, the driver tries to do splice_write.
= This induces oops in sg_init_table().
[BUG2] No lock for
On Mon, Jul 15, 2013 at 09:31:49PM +0300, Michael S. Tsirkin wrote:
The following changes since commit 09a34c8404c1d4c5782de319c02e1d742c57875c:
vhost/test: update test after vhost cleanups (2013-07-07 18:02:25 +0300)
are available in the git repository at:
On Fri, Jul 19, 2013 at 01:58:05PM -0700, H. Peter Anvin wrote:
On 07/19/2013 12:14 PM, Greg KH wrote:
The errors that the kexec tools seem to run into is finding the memory
to place the new kernel into, is that just an issue that PV guests
aren't given enough kernel memory in which to
Daniel Kiper daniel.ki...@oracle.com writes:
On Fri, Jul 19, 2013 at 01:58:05PM -0700, H. Peter Anvin wrote:
On 07/19/2013 12:14 PM, Greg KH wrote:
The errors that the kexec tools seem to run into is finding the memory
to place the new kernel into, is that just an issue that PV guests
On 07/22/2013 10:20 AM, Eric W. Biederman wrote:
Also, in any virtualized environment the hypervisor can do a better job
for things like kdump, simply because it can provide two things that are
otherwise hard to do:
1. a known-good system state;
2. a known-clean kdump image.
As such, I do
github link: https://github.com/ktraghavendra/linux/tree/pvspinlock_v11
And chance you have a backup git tree? I get:
This repository is temporarily unavailable.
Please note that we set SPIN_THRESHOLD = 32k with this series,
that would eatup little bit of overcommit performance of PLE
On 07/22/2013 11:33 AM, Greg KH wrote:
I don't care about kdump, I care about kexec on domU for people who are
running on cloud providers with old versions of Xen so that they can
control what kernel they can boot, when they want to boot it. If kdump
works as well, that's just a bonus, but
The PTR_ERR(NULL) here is not useful.
Signed-off-by: Dan Carpenter dan.carpen...@oracle.com
---
v2: completely different
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 1b456fe..4cf46d8 100644
--- a/drivers/char/virtio_console.c
+++
Amit Shah amit.s...@redhat.com writes:
On (Fri) 19 Jul 2013 [18:17:32], Jason Wang wrote:
On 07/19/2013 03:48 PM, Amit Shah wrote:
On (Fri) 19 Jul 2013 [15:03:50], Jason Wang wrote:
On 07/19/2013 04:16 AM, Amit Shah wrote:
Between poll() being called and processed, the port can be
On 07/23/2013 01:06 AM, Konrad Rzeszutek Wilk wrote:
github link: https://github.com/ktraghavendra/linux/tree/pvspinlock_v11
And chance you have a backup git tree? I get:
This repository is temporarily unavailable.
I only have it on local apart from there :(.
Hope it was a temporary github
On 07/22/2013 01:45 PM, Rusty Russell wrote:
Amit Shah amit.s...@redhat.com writes:
On (Fri) 19 Jul 2013 [18:17:32], Jason Wang wrote:
On 07/19/2013 03:48 PM, Amit Shah wrote:
On (Fri) 19 Jul 2013 [15:03:50], Jason Wang wrote:
On 07/19/2013 04:16 AM, Amit Shah wrote:
Between poll() being
Amit Shah amit.s...@redhat.com writes:
On (Mon) 22 Jul 2013 [13:00:43], Yoshihiro YUNOMAE wrote:
Hi,
This patch set fixes two bugs of splice_write in the virtio-console driver.
[BUG1] Although pipe-nrbufs is empty, the driver tries to do splice_write.
= This induces oops in
On Mon, Jul 22, 2013 at 11:41:00PM +0300, Dan Carpenter wrote:
The PTR_ERR(NULL) here is not useful.
Signed-off-by: Dan Carpenter dan.carpen...@oracle.com
---
v2: completely different
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 1b456fe..4cf46d8 100644
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