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From: Pan Xinhui > Sent: 20 October 2016 22:28 > Commit ("x86, kvm: support vcpu preempted check") add one field "__u8 > preempted" into struct kvm_steal_time. This field tells if one vcpu is > running or not. > > It is zero if 1) some old KVM deos not support this filed. 2) t...

From: Pan Xinhui > Sent: 20 October 2016 22:28 > Commit ("x86, kvm: support vcpu preempted check") add one field "__u8 > preempted" into struct kvm_steal_time. This field tells if one vcpu is > running or not. > > It is zero if 1) some old KVM deos not support this filed. 2) t...

On Mon, Dec 05, 2016 at 10:19:22AM -0500, Pan Xinhui wrote: > pSeries/powerNV will use qspinlock from now on. > > Signed-off-by: Pan Xinhui <xinhui.pan at linux.vnet.ibm.com> > --- > arch/powerpc/platforms/pseries/Kconfig | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/arch/powerpc/platforms/pseries/K...

On Mon, Dec 05, 2016 at 10:19:22AM -0500, Pan Xinhui wrote: > pSeries/powerNV will use qspinlock from now on. > > Signed-off-by: Pan Xinhui <xinhui.pan at linux.vnet.ibm.com> > --- > arch/powerpc/platforms/pseries/Kconfig | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/arch/powerpc/platforms/pseries/K...

Hi Xinhui, 2016-06-28 22:43 GMT+08:00 Pan Xinhui <xinhui.pan at linux.vnet.ibm.com>: > This is to fix some lock holder preemption issues. Some other locks > implementation do a spin loop before acquiring the lock itself. Currently > kernel has an interface of bool vcpu_is_preempted(int cpu). I...

Hi Xinhui, 2016-06-28 22:43 GMT+08:00 Pan Xinhui <xinhui.pan at linux.vnet.ibm.com>: > This is to fix some lock holder preemption issues. Some other locks > implementation do a spin loop before acquiring the lock itself. Currently > kernel has an interface of bool vcpu_is_preempted(int cpu). I...

On Wed, May 25, 2016 at 04:18:08PM +0800, Pan Xinhui wrote: > cmpxchg_release is light-wight than cmpxchg, we can gain a better > performace then. On some arch like ppc, barrier impact the performace > too much. > > Suggested-by: Boqun Feng <boqun.feng at gmail.com> > Signed-off-by: Pan Xinhui <xinhui.pan at linux.vnet.ib...

On Wed, May 25, 2016 at 04:18:08PM +0800, Pan Xinhui wrote: > cmpxchg_release is light-wight than cmpxchg, we can gain a better > performace then. On some arch like ppc, barrier impact the performace > too much. > > Suggested-by: Boqun Feng <boqun.feng at gmail.com> > Signed-off-by: Pan Xinhui <xinhui.pan at linux.vnet.ib...

...22607.4 lpm Shell Scripts (8 concurrent) | 3531.4 lpm | 3211.9 lpm System Call Overhead | 10385653.0 lps | 10419979.0 lps Christian Borntraeger (1): s390/spinlock: Provide vcpu_is_preempted Juergen Gross (1): x86, xen: support vcpu preempted check Pan Xinhui (7): kernel/sched: introduce vcpu preempted check interface locking/osq: Drop the overload of osq_lock() kernel/locking: Drop the overload of {mutex,rwsem}_spin_on_owner powerpc/spinlock: support vcpu preempted check x86, paravirt: Add interface to support kvm/xen vcpu preempted check x...

...22607.4 lpm Shell Scripts (8 concurrent) | 3531.4 lpm | 3211.9 lpm System Call Overhead | 10385653.0 lps | 10419979.0 lps Christian Borntraeger (1): s390/spinlock: Provide vcpu_is_preempted Juergen Gross (1): x86, xen: support vcpu preempted check Pan Xinhui (7): kernel/sched: introduce vcpu preempted check interface locking/osq: Drop the overload of osq_lock() kernel/locking: Drop the overload of {mutex,rwsem}_spin_on_owner powerpc/spinlock: support vcpu preempted check x86, paravirt: Add interface to support kvm/xen vcpu preempted check x...

From: Pan Xinhui <xinhui.pan at linux.vnet.ibm.com> This patch aims to enable qspinlock on PPC. And on pseries platform, it also support paravirt qspinlock. Signed-off-by: Pan Xinhui <xinhui.pan at linux.vnet.ibm.com> --- arch/powerpc/include/asm/qspinlock.h | 37 +++++++++++++++ arch/p...

From: Pan Xinhui <xinhui.pan at linux.vnet.ibm.com> This patch aims to enable qspinlock on PPC. And on pseries platform, it also support paravirt qspinlock. Signed-off-by: Pan Xinhui <xinhui.pan at linux.vnet.ibm.com> --- arch/powerpc/include/asm/qspinlock.h | 37 +++++++++++++++ arch/p...

...all cpus. _____test________________spinlcok______________pv-qspinlcok_____ |schedule() loops| 322811921 | 311449290 | kernel compiling test: build a linux kernel image to see how long it took _____test________________spinlcok______________pv-qspinlcok_____ | compiling takes| 22m | 22m | Pan Xinhui (6): qspinlock: powerpc support qspinlock powerpc: pseries/Kconfig: Add qspinlock build config powerpc: lib/locks.c: Add cpu yield/wake helper function pv-qspinlock: powerpc support pv-qspinlock pv-qspinlock: use cmpxchg_release in __pv_queued_spin_unlock powerpc: pseries: Add pv-qspinl...

...all cpus. _____test________________spinlcok______________pv-qspinlcok_____ |schedule() loops| 322811921 | 311449290 | kernel compiling test: build a linux kernel image to see how long it took _____test________________spinlcok______________pv-qspinlcok_____ | compiling takes| 22m | 22m | Pan Xinhui (6): qspinlock: powerpc support qspinlock powerpc: pseries/Kconfig: Add qspinlock build config powerpc: lib/locks.c: Add cpu yield/wake helper function pv-qspinlock: powerpc support pv-qspinlock pv-qspinlock: use cmpxchg_release in __pv_queued_spin_unlock powerpc: pseries: Add pv-qspinl...

...on_owner.is 2.49% sched-messaging [kernel.vmlinux] [k] system_call We introduce interface bool vcpu_is_preempted(int cpu) and use it in some spin loops of osq_lock, rwsem_spin_on_owner and mutex_spin_on_owner. These spin_on_onwer variant also cause rcu stall before we apply this patch set Pan Xinhui (4): kernel/sched: introduce vcpu preempted check interface powerpc/spinlock: support vcpu preempted check locking/osq: Drop the overload of osq_lock() kernel/locking: Drop the overload of {mutex,rwsem}_spin_on_owner arch/powerpc/include/asm/spinlock.h | 18 ++++++++++++++++++ include/lin...

...on_owner.is 2.49% sched-messaging [kernel.vmlinux] [k] system_call We introduce interface bool vcpu_is_preempted(int cpu) and use it in some spin loops of osq_lock, rwsem_spin_on_owner and mutex_spin_on_owner. These spin_on_onwer variant also cause rcu stall before we apply this patch set Pan Xinhui (4): kernel/sched: introduce vcpu preempted check interface powerpc/spinlock: support vcpu preempted check locking/osq: Drop the overload of osq_lock() kernel/locking: Drop the overload of {mutex,rwsem}_spin_on_owner arch/powerpc/include/asm/spinlock.h | 18 ++++++++++++++++++ include/lin...

On 21/10/2016 20:39, rkrcmar at redhat.com wrote: > 2016-10-21 11:27+0000, David Laight: >> From: Pan Xinhui >>> Sent: 20 October 2016 22:28 >>> Commit ("x86, kvm: support vcpu preempted check") add one field "__u8 >>> preempted" into struct kvm_steal_time. This field tells if one vcpu is >>> running or not. >>> >>> It is zero if 1)...

On 21/10/2016 20:39, rkrcmar at redhat.com wrote: > 2016-10-21 11:27+0000, David Laight: >> From: Pan Xinhui >>> Sent: 20 October 2016 22:28 >>> Commit ("x86, kvm: support vcpu preempted check") add one field "__u8 >>> preempted" into struct kvm_steal_time. This field tells if one vcpu is >>> running or not. >>> >>> It is zero if 1)...

On Tue, 2016-06-28 at 10:43 -0400, Pan Xinhui wrote: > This is to fix some lock holder preemption issues. Some other locks > implementation do a spin loop before acquiring the lock itself. Currently > kernel has an interface of bool vcpu_is_preempted(int cpu). It take the cpu ^^ takes > as parameter and return true if the c...

On Tue, 2016-06-28 at 10:43 -0400, Pan Xinhui wrote: > This is to fix some lock holder preemption issues. Some other locks > implementation do a spin loop before acquiring the lock itself. Currently > kernel has an interface of bool vcpu_is_preempted(int cpu). It take the cpu ^^ takes > as parameter and return true if the c...