Re: [PATCH v3] lib/bitmap.c: enhance bitmap syntax

在 16/7/17 21:50, Pan Xinhui 写道: 在 16/7/17 16:10, Noam Camus 写道: From: Noam Camus <noa...@mellanox.com> Today there are platforms with many CPUs (up to 4K). Trying to boot only part of the CPUs may result in too long string. For example lets take NPS platform that is part of ar

Re: [PATCH v3] lib/bitmap.c: enhance bitmap syntax

在 16/7/17 16:10, Noam Camus 写道: From: Noam Camus Today there are platforms with many CPUs (up to 4K). Trying to boot only part of the CPUs may result in too long string. For example lets take NPS platform that is part of arch/arc. This platform have SMP system with 256

Re: [PATCH v2 2/5] locking/pvqspinlock: Fix missed PV wakeup problem

在 16/7/15 16:47, Peter Zijlstra 写道: So the reason I never get around to this is because the patch stinks. It simply doesn't make sense... Remember, the harder you make a reviewer work the less likely the review will be done. Present things in clear concise language and draw a picture. On

Re: [PATCH v2 2/4] powerpc/spinlock: support vcpu preempted check

Hi, Baibir sorry for late responce, I missed reading your mail. 在 16/7/6 18:54, Balbir Singh 写道: 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

[PATCH v4] locking/qrwlock: Fix write unlock issue in big endian

From: pan xinhui <xinhui@linux.vnet.ibm.com> This patch aims to get rid of endianness in queued_write_unlock(). We want to set __qrwlock->wmode to NULL, however the address is not >cnts in big endian machine. That causes queued_write_unlock() write NULL to the wrong field of __

[PATCH 2/3] powerpc/spinlock: support vcpu preempted check

n.f...@gmail.com> Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> --- arch/powerpc/include/asm/lppaca.h | 6 ++ arch/powerpc/include/asm/spinlock.h | 15 +++ 2 files changed, 21 insertions(+) diff --git a/arch/powerpc/include/asm/lppaca.h b/arch/powerpc/include/

[PATCH 1/3] kernel/sched: introduce vcpu preempted check interface

pteempted check. archs can implement it by define arch_vcpu_is_preempted(). Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> --- include/linux/sched.h | 9 + 1 file changed, 9 insertions(+) diff --git a/include/linux/sched.h b/include/linux/sched.h index 6e42ada..dc0a9c3

[PATCH 3/3] locking/osq: Drop the overload of osq_lock()

mlinux] [k] copypage_power7 2.64% sched-messaging [kernel.vmlinux] [k] rwsem_spin_on_owner 2.00% sched-messaging [kernel.vmlinux] [k] osq_lock Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> --- kernel/locking/osq_lock.c | 16 +++- 1 file changed, 15 insertio

[PATCH 0/3] implement vcpu preempted check

so need fix other XXX_spin_on_owner later based on this patch set. these spin_on_onwer variant cause rcu stall. Pan Xinhui (3): powerpc/spinlock: support vcpu preempted check locking/osq: Drop the overload of osq_lock() kernel/sched: introduce vcpu preempted check interface arch/powerpc/

Re: [PATCH v2] locking/pvqspinlock: Relax cmpxchg's to improve performance on some archs

在 2017/2/8 14:09, Boqun Feng 写道: On Wed, Feb 08, 2017 at 12:05:40PM +0800, Boqun Feng wrote: On Wed, Feb 08, 2017 at 11:39:10AM +0800, Xinhui Pan wrote: 2016-12-26 4:26 GMT+08:00 Waiman Long : A number of cmpxchg calls in qspinlock_paravirt.h were replaced by more

Re: [PATCH v2] locking/pvqspinlock: Relax cmpxchg's to improve performance on some archs

在 2017/2/8 14:09, Boqun Feng 写道: On Wed, Feb 08, 2017 at 12:05:40PM +0800, Boqun Feng wrote: On Wed, Feb 08, 2017 at 11:39:10AM +0800, Xinhui Pan wrote: 2016-12-26 4:26 GMT+08:00 Waiman Long : A number of cmpxchg calls in qspinlock_paravirt.h were replaced by more

Re: [PATCH v2] locking/pvqspinlock: Relax cmpxchg's to improve performance on some archs

在 2017/2/8 14:09, Boqun Feng 写道: On Wed, Feb 08, 2017 at 12:05:40PM +0800, Boqun Feng wrote: On Wed, Feb 08, 2017 at 11:39:10AM +0800, Xinhui Pan wrote: 2016-12-26 4:26 GMT+08:00 Waiman Long : A number of cmpxchg calls in qspinlock_paravirt.h were replaced by more

[PATCH] powerpc/xmon: Fix an unexpected xmon onoff state change

Once xmon is triggered by sysrq-x, it is enabled always afterwards even if it is disabled during boot. This will cause a system reset interrut fail to dump. So keep xmon in its original state after exit. Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> --- arch/powerpc/xmon/xmon

[PATCH] powerpc/xmon: add turn off xmon option

commands. Turn xmon off if 'z' is following. Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> --- arch/powerpc/xmon/xmon.c | 12 +--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c index 9c0e17c..2f4e7b1

Re: [PATCH] powerpc/xmon: Fix an unexpected xmon onoff state change

在 2017/2/16 18:57, Guilherme G. Piccoli 写道: On 16/02/2017 03:09, Michael Ellerman wrote: Pan Xinhui <xinhui@linux.vnet.ibm.com> writes: Once xmon is triggered by sysrq-x, it is enabled always afterwards even if it is disabled during boot. This will cause a system reset interru

Re: [PATCH] powerpc/xmon: Fix an unexpected xmon onoff state change

在 2017/2/17 14:05, Michael Ellerman 写道: Pan Xinhui <xin...@linux.vnet.ibm.com> writes: diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c index 9c0e17c..f6e5c3d 100644 --- a/arch/powerpc/xmon/xmon.c +++ b/arch/powerpc/xmon/xmon.c @@ -76,6 +76,7 @@ static int xmon_gate;

Re: [PATCH v5] locking/pvqspinlock: Relax cmpxchg's to improve performance on some archs

--- --- 4 4053.3 Mop/s 4223.7 Mop/s +4.2% 8 3310.4 Mop/s 3406.0 Mop/s +2.9% 12 2576.4 Mop/s 2674.6 Mop/s +3.8% Signed-off-by: Waiman Long <long...@redhat.com> --- Works on my side :) Reviewed-by: Pan Xinhui <xinhui@linux.vnet.ibm.c

Re: [PATCH v2 1/1] s390/spinlock: Provide vcpu_is_preempted

在 2016/9/30 13:52, Boqun Feng 写道: On Fri, Sep 30, 2016 at 12:49:52PM +0800, Pan Xinhui wrote: 在 2016/9/29 23:51, Christian Borntraeger 写道: this implements the s390 backend for commit "kernel/sched: introduce vcpu preempted check interface" by reworking the existing smp_vcpu

Re: [PATCH v2 1/1] s390/spinlock: Provide vcpu_is_preempted

在 2016/9/29 23:51, Christian Borntraeger 写道: this implements the s390 backend for commit "kernel/sched: introduce vcpu preempted check interface" by reworking the existing smp_vcpu_scheduled into arch_vcpu_is_preempted. We can then also get rid of the local cpu_is_preempted function by moving

Re: [PATCH v3 0/4] implement vcpu preempted check

在 2016/9/29 18:31, Peter Zijlstra 写道: On Thu, Sep 29, 2016 at 12:23:19PM +0200, Christian Borntraeger wrote: On 09/29/2016 12:10 PM, Peter Zijlstra wrote: On Thu, Jul 21, 2016 at 07:45:10AM -0400, Pan Xinhui wrote: change from v2: no code change, fix typos, update some comments

Re: [PATCH v3 0/4] implement vcpu preempted check

hi, Paolo thanks for your reply. 在 2016/9/30 14:58, Paolo Bonzini 写道: Please consider s390 and (x86/arm) KVM. Once we have a few, more can follow later, but I think its important to not only have PPC support for this. Actually the s390 preemted check via sigp sense running is

Re: [PATCH v3 0/4] implement vcpu preempted check

在 2016/9/30 17:08, Paolo Bonzini 写道: On 30/09/2016 10:52, Pan Xinhui wrote: x86 has no hypervisor support, and I'd like to understand the desired semantics first, so I don't think it should block this series. In Once a guest do a hypercall or something similar, IOW

[PATCH RFC] perf bench futex: Support running benchmark while some cpus are offline

orrect cpu number. Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> --- tools/perf/bench/futex-hash.c | 2 +- tools/perf/bench/futex-lock-pi.c | 2 +- tools/perf/bench/futex-requeue.c | 2 +- tools/perf/bench/futex-wake-parallel.c | 2 +- tools/perf/be

[PATCH v7 6/6] powerpc: pSeries: Add pv-qspinlock build config/make

pSeries run as a guest and might need pv-qspinlock. Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> --- arch/powerpc/kernel/Makefile | 1 + arch/powerpc/platforms/pseries/Kconfig | 8 2 files changed, 9 insertions(+) diff --git a/arch/powerpc/kernel/Makefile

[PATCH v7 5/6] powerpc/pv-qspinlock: powerpc support pv-qspinlock

in the hash table might not be the correct lock holder, as for performace issue, we does not take care of hash conflict. Also introduce spin_lock_holder, which tells who owns the lock now. currently the only user is spin_unlock_wait. Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.

[PATCH v7 1/6] pv-qspinlock: use cmpxchg_release in __pv_queued_spin_unlock

-by: Boqun Feng <boqun.f...@gmail.com> Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> --- kernel/locking/qspinlock_paravirt.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/locking/qspinlock_paravirt.h b/kernel/locking/qspinlock_paravirt.h index 8a99

[PATCH v7 3/6] powerpc: pseries/Kconfig: Add qspinlock build config

pseries will use qspinlock by default. Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> --- arch/powerpc/platforms/pseries/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/powerpc/platforms/pseries/Kconfig b/arch/powerpc/platforms/pseries/Kconfig index bec90fb..f

[PATCH v7 2/6] powerpc/qspinlock: powerpc support qspinlock

two endianness system. We override some arch_spin_xxx as powerpc has io_sync stuff which makes sure the io operations are protected by the lock correctly. There is another special case, see commit 2c610022711 ("locking/qspinlock: Fix spin_unlock_wait() some more") Signed-off-by: Pan X

[PATCH v7 0/6] Implement qspinlock/pv-qspinlock on ppc

1008.3 1122.61134.2 = System Benchmarks Index Score 1072.0 1108.91050.6 -------- Pan Xinhui (6): pv-qspin

[PATCH v7 4/6] powerpc: lib/locks.c: Add cpu yield/wake helper function

will introduce latency and a little overhead. And we do NOT want to suffer any latency on some cases, e.g. in interrupt handler. The second parameter *confer* can indicate such case. __spin_wake_cpu is simpiler, it will wake up one vcpu regardless of its current vcpu state. Signed-off-by: Pan

[PATCH v4 5/5] x86, kvm: support vcpu preempted check

Scripts (1 concurrent) |23224.3 lpm |22607.4 lpm Shell Scripts (8 concurrent) | 3531.4 lpm | 3211.9 lpm System Call Overhead | 10385653.0 lps | 10419979.0 lps Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> --- arch/x86/inclu

[PATCH v4 4/5] powerpc/spinlock: support vcpu preempted check

->yiled_count keeps zero on powerNV. So we can just skip the machine type check. Suggested-by: Boqun Feng <boqun.f...@gmail.com> Suggested-by: Peter Zijlstra (Intel) <pet...@infradead.org> Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> --- arch/powerpc/include/asm/spinl

[PATCH v4 3/5] kernel/locking: Drop the overload of {mutex,rwsem}_spin_on_owner

essaging [kernel.vmlinux] [k] system_call 2.69% sched-messaging [kernel.vmlinux] [k] wait_consider_task Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> --- kernel/locking/mutex.c | 15 +-- kernel/locking/rwsem-xadd.c | 16 +--- 2 files changed, 26 in

[PATCH v4 0/5] implement vcpu preempted check

ncurrent) |23224.3 lpm |22607.4 lpm Shell Scripts (8 concurrent) | 3531.4 lpm | 3211.9 lpm System Call Overhead | 10385653.0 lps | 10419979.0 lps Pan Xinhui (5): kernel/sched: introduce vcpu preempted check interface locking/osq: Drop the

[PATCH v4 2/5] locking/osq: Drop the overload of osq_lock()

call_common 2.83% sched-messaging [kernel.vmlinux] [k] copypage_power7 2.64% sched-messaging [kernel.vmlinux] [k] rwsem_spin_on_owner 2.00% sched-messaging [kernel.vmlinux] [k] osq_lock Suggested-by: Boqun Feng <boqun.f...@gmail.com> Signed-off-by: Pan Xinhui <xinhui...

[PATCH v4 1/5] kernel/sched: introduce vcpu preempted check interface

. Suggested-by: Peter Zijlstra (Intel) <pet...@infradead.org> Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> --- include/linux/sched.h | 12 1 file changed, 12 insertions(+) diff --git a/include/linux/sched.h b/include/linux/sched.h index 348f51b..44

[PATCH v5 1/9] kernel/sched: introduce vcpu preempted check interface

. Suggested-by: Peter Zijlstra (Intel) <pet...@infradead.org> Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> Acked-by: Christian Borntraeger <borntrae...@de.ibm.com> Tested-by: Juergen Gross <jgr...@suse.com> --- include/linux/sched.h | 12 1 fil

[PATCH v5 0/9] implement vcpu preempted check

ripts (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: i

[PATCH v5 5/9] x86, paravirt: Add interface to support kvm/xen vcpu preempted check

the spin loops upon on the retval of vcpu_is_preempted. As kernel has used this interface, So lets support it. To deal with kernel and kvm/xen, add vcpu_is_preempted into struct pv_lock_ops. Then kvm or xen could provide their own implementation to support vcpu_is_preempted. Signed-off-by: Pan

[PATCH v5 3/9] kernel/locking: Drop the overload of {mutex,rwsem}_spin_on_owner

essaging [kernel.vmlinux] [k] system_call 2.69% sched-messaging [kernel.vmlinux] [k] wait_consider_task Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> Acked-by: Christian Borntraeger <borntrae...@de.ibm.com> Tested-by: Juergen Gross <jgr...@suse.com> --- kernel

[PATCH v5 4/9] powerpc/spinlock: support vcpu preempted check

->yiled_count keeps zero on powerNV. So we can just skip the machine type check. Suggested-by: Boqun Feng <boqun.f...@gmail.com> Suggested-by: Peter Zijlstra (Intel) <pet...@infradead.org> Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> --- arch/powerpc/include/asm/spinl

Re: [PATCH v4 5/5] x86, kvm: support vcpu preempted check

在 2016/10/24 23:18, Paolo Bonzini 写道: On 24/10/2016 17:14, Radim Krčmář wrote: 2016-10-24 16:39+0200, Paolo Bonzini: On 19/10/2016 19:24, Radim Krčmář wrote: + if (vcpu->arch.st.msr_val & KVM_MSR_ENABLED) + if (kvm_read_guest_cached(vcpu->kvm, >arch.st.stime, +

[PATCH v5 6/9] x86, kvm: support vcpu preempted check

Call Overhead | 10385653.0 lps | 10419979.0 lps Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> --- arch/x86/include/uapi/asm/kvm_para.h | 3 ++- arch/x86/kernel/kvm.c| 12 arch/x86/kvm/x86.c | 18 +++

[PATCH v5 8/9] s390/spinlock: Provide vcpu_is_preempted

From: Christian Borntraeger this implements the s390 backend for commit "kernel/sched: introduce vcpu preempted check interface" by reworking the existing smp_vcpu_scheduled into arch_vcpu_is_preempted. We can then also get rid of the local cpu_is_preempted function by

[PATCH v5 9/9] Documentation: virtual: kvm: Support vcpu preempted check

n preempted. Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> --- Documentation/virtual/kvm/msr.txt | 8 +++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/Documentation/virtual/kvm/msr.txt b/Documentation/virtual/kvm/msr.txt index 2a71c8f..3376f13 100644 --- a

[PATCH v5 2/9] locking/osq: Drop the overload of osq_lock()

call_common 2.83% sched-messaging [kernel.vmlinux] [k] copypage_power7 2.64% sched-messaging [kernel.vmlinux] [k] rwsem_spin_on_owner 2.00% sched-messaging [kernel.vmlinux] [k] osq_lock Suggested-by: Boqun Feng <boqun.f...@gmail.com> Signed-off-by: Pan Xinhui <xinhui@linux

[PATCH v5 7/9] x86, xen: support vcpu preempted check

early yielding. A quick test (4 vcpus on 1 physical cpu doing a parallel build job with "make -j 8") reduced system time by about 5% with this patch. Signed-off-by: Juergen Gross <jgr...@suse.com> Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> --- arch/x86/xe

Re: [PATCH v4 0/5] implement vcpu preempted check

在 2016/10/19 23:58, Juergen Gross 写道: On 19/10/16 12:20, Pan Xinhui wrote: change from v3: add x86 vcpu preempted check patch change from v2: no code change, fix typos, update some comments change from v1: a simplier definition of default vcpu_is_preempted skip

Re: [PATCH v4 5/5] x86, kvm: support vcpu preempted check

在 2016/10/20 01:24, Radim Krčmář 写道: 2016-10-19 06:20-0400, Pan Xinhui: 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 takes the cpu

Re: [PATCH v7 06/11] x86, paravirt: Add interface to support kvm/xen vcpu preempted check

在 2016/11/16 18:23, Peter Zijlstra 写道: On Wed, Nov 16, 2016 at 12:19:09PM +0800, Pan Xinhui wrote: Hi, Peter. I think we can avoid a function call in a simpler way. How about below static inline bool vcpu_is_preempted(int cpu) { /* only set in pv case

Re: [PATCH v7 06/11] x86, paravirt: Add interface to support kvm/xen vcpu preempted check

在 2016/11/15 23:47, Peter Zijlstra 写道: On Wed, Nov 02, 2016 at 05:08:33AM -0400, Pan Xinhui wrote: diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h index 0f400c0..38c3bb7 100644 --- a/arch/x86/include/asm/paravirt_types.h +++ b/arch/x86/include/asm

[PATCH v6 02/11] locking/osq: Drop the overload of osq_lock()

call_common 2.83% sched-messaging [kernel.vmlinux] [k] copypage_power7 2.64% sched-messaging [kernel.vmlinux] [k] rwsem_spin_on_owner 2.00% sched-messaging [kernel.vmlinux] [k] osq_lock Suggested-by: Boqun Feng <boqun.f...@gmail.com> Signed-off-by: Pan Xinhui <xinhui@linux

[PATCH v6 09/11] x86, kernel/kvm.c: support vcpu preempted check

concurrent) | 3531.4 lpm | 3211.9 lpm System Call Overhead | 10385653.0 lps | 10419979.0 lps Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> --- arch/x86/kernel/kvm.c | 12 1 file changed, 12 insertions(+) diff --git a/arch/x86/ker

[PATCH v6 10/11] x86, xen: support vcpu preempted check

early yielding. A quick test (4 vcpus on 1 physical cpu doing a parallel build job with "make -j 8") reduced system time by about 5% with this patch. Signed-off-by: Juergen Gross <jgr...@suse.com> Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> --- arch/x86/xe

[PATCH v6 08/11] x86, kvm/x86.c: support vcpu preempted check

kvm_steal_time ::preempted to indicate that if one vcpu is running or not. Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> --- arch/x86/include/uapi/asm/kvm_para.h | 4 +++- arch/x86/kvm/x86.c | 16 2 files changed, 19 insertions(+), 1 deletion(-)

[PATCH v6 04/11] powerpc/spinlock: support vcpu preempted check

->yiled_count keeps zero on powerNV. So we can just skip the machine type check. Suggested-by: Boqun Feng <boqun.f...@gmail.com> Suggested-by: Peter Zijlstra (Intel) <pet...@infradead.org> Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> --- arch/powerpc/include/asm/spinl

[PATCH v6 11/11] Documentation: virtual: kvm: Support vcpu preempted check

u has been preempted. Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> Acked-by: Radim Krčmář <rkrc...@redhat.com> --- Documentation/virtual/kvm/msr.txt | 9 - 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/Documentation/virtual/kvm/msr.txt b/Documentation/v

[PATCH v6 07/11] KVM: Introduce kvm_write_guest_offset_cached

It allows us to update some status or field of one struct partially. We can also save one kvm_read_guest_cached if we just update one filed of the struct regardless of its current value. Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> --- include/linux/kvm_host.h | 2 ++ vi

[PATCH v6 06/11] x86, paravirt: Add interface to support kvm/xen vcpu preempted check

the spin loops upon on the retval of vcpu_is_preempted. As kernel has used this interface, So lets support it. To deal with kernel and kvm/xen, add vcpu_is_preempted into struct pv_lock_ops. Then kvm or xen could provide their own implementation to support vcpu_is_preempted. Signed-off-by: Pan

[PATCH v6 01/11] kernel/sched: introduce vcpu preempted check interface

. Suggested-by: Peter Zijlstra (Intel) <pet...@infradead.org> Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> Acked-by: Christian Borntraeger <borntrae...@de.ibm.com> Tested-by: Juergen Gross <jgr...@suse.com> --- include/linux/sched.h | 12 1 fil

[PATCH v6 00/11] implement vcpu preempted check

79.0 lps Christian Borntraeger (1): s390/spinlock: Provide vcpu_is_preempted Juergen Gross (1): x86, xen: support vcpu preempted check Pan Xinhui (9): kernel/sched: introduce vcpu preempted check interface locking/osq: Drop the overload of osq_lock() kernel/locking: Drop the overload o

[PATCH v6 03/11] kernel/locking: Drop the overload of {mutex,rwsem}_spin_on_owner

essaging [kernel.vmlinux] [k] system_call 2.69% sched-messaging [kernel.vmlinux] [k] wait_consider_task Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> Acked-by: Christian Borntraeger <borntrae...@de.ibm.com> Tested-by: Juergen Gross <jgr...@suse.com> --- kernel

[PATCH v6 05/11] s390/spinlock: Provide vcpu_is_preempted

From: Christian Borntraeger this implements the s390 backend for commit "kernel/sched: introduce vcpu preempted check interface" by reworking the existing smp_vcpu_scheduled into arch_vcpu_is_preempted. We can then also get rid of the local cpu_is_preempted function by

[PATCH v7 02/11] locking/osq: Drop the overload of osq_lock()

call_common 2.83% sched-messaging [kernel.vmlinux] [k] copypage_power7 2.64% sched-messaging [kernel.vmlinux] [k] rwsem_spin_on_owner 2.00% sched-messaging [kernel.vmlinux] [k] osq_lock Suggested-by: Boqun Feng <boqun.f...@gmail.com> Signed-off-by: Pan Xinhui <xinhui@linux

[PATCH v7 00/11] implement vcpu preempted check

tem 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 (9): kernel/sched: introduce vcpu preempted check interface locking/o

[PATCH v7 03/11] kernel/locking: Drop the overload of {mutex,rwsem}_spin_on_owner

essaging [kernel.vmlinux] [k] system_call 2.69% sched-messaging [kernel.vmlinux] [k] wait_consider_task Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> Acked-by: Christian Borntraeger <borntrae...@de.ibm.com> Acked-by: Paolo Bonzini <pbonz...@redhat.com> Tested-by: Juer

[PATCH v7 01/11] kernel/sched: introduce vcpu preempted check interface

. Suggested-by: Peter Zijlstra (Intel) <pet...@infradead.org> Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> Acked-by: Christian Borntraeger <borntrae...@de.ibm.com> Acked-by: Paolo Bonzini <pbonz...@redhat.com> Tested-by: Juergen Gross <jgr...@suse.com> -

[PATCH v7 04/11] powerpc/spinlock: support vcpu preempted check

->yiled_count keeps zero on PowerNV. So we can just skip the machine type check. Suggested-by: Boqun Feng <boqun.f...@gmail.com> Suggested-by: Peter Zijlstra (Intel) <pet...@infradead.org> Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> --- arch/powerpc/include/asm/spinlock.h

[PATCH v7 07/11] KVM: Introduce kvm_write_guest_offset_cached

It allows us to update some status or field of one struct partially. We can also save one kvm_read_guest_cached if we just update one filed of the struct regardless of its current value. Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> Acked-by: Paolo Bonzini <pbonz...@r

[PATCH v7 05/11] s390/spinlock: Provide vcpu_is_preempted

From: Christian Borntraeger this implements the s390 backend for commit "kernel/sched: introduce vcpu preempted check interface" by reworking the existing smp_vcpu_scheduled into arch_vcpu_is_preempted. We can then also get rid of the local cpu_is_preempted function by

[PATCH v7 08/11] x86, kvm/x86.c: support vcpu preempted check

kvm_steal_time ::preempted to indicate that if one vcpu is running or not. Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> Acked-by: Paolo Bonzini <pbonz...@redhat.com> --- arch/x86/include/uapi/asm/kvm_para.h | 4 +++- arch/x86/kvm/x86.c | 16 +

[PATCH v7 10/11] x86, xen: support vcpu preempted check

early yielding. A quick test (4 vcpus on 1 physical cpu doing a parallel build job with "make -j 8") reduced system time by about 5% with this patch. Signed-off-by: Juergen Gross <jgr...@suse.com> Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> --- arch/x86/xe

[PATCH v7 11/11] Documentation: virtual: kvm: Support vcpu preempted check

u has been preempted. Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> Acked-by: Radim Krčmář <rkrc...@redhat.com> Acked-by: Paolo Bonzini <pbonz...@redhat.com> --- Documentation/virtual/kvm/msr.txt | 9 - 1 file changed, 8 insertions(+), 1 deletion(-) diff --git

[PATCH v7 09/11] x86, kernel/kvm.c: support vcpu preempted check

concurrent) | 3531.4 lpm | 3211.9 lpm System Call Overhead | 10385653.0 lps | 10419979.0 lps Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> Acked-by: Paolo Bonzini <pbonz...@redhat.com> --- arch/x86/kernel/kvm.c | 12 1 file

[PATCH v7 06/11] x86, paravirt: Add interface to support kvm/xen vcpu preempted check

the spin loops upon the retval of vcpu_is_preempted. As kernel has used this interface, So lets support it. To deal with kernel and kvm/xen, add vcpu_is_preempted into struct pv_lock_ops. Then kvm or xen could provide their own implementation to support vcpu_is_preempted. Signed-off-by: Pan Xinhui

Re: [Xen-devel] [PATCH v6 00/11] implement vcpu preempted check

在 2016/10/29 03:38, Konrad Rzeszutek Wilk 写道: On Fri, Oct 28, 2016 at 04:11:16AM -0400, Pan Xinhui wrote: change from v5: spilt x86/kvm patch into guest/host part. introduce kvm_write_guest_offset_cached. fix some typos. rebase patch onto 4.9.2 change from v4

Re: [PATCH 2/2] x86, paravirt: Fix bool return type for PVOP_CALL

hi, Peter I think I know the point. then could we just let __eax rettype(here is bool), not unsigned long? I does not do tests for my thoughts. @@ -461,7 +461,9 @@ int paravirt_disable_iospace(void); #define PVOP_VCALL_ARGS \

[PATCH] locking/pvqspinlock: Wait early if vcpu is preempted

If prev node is not in runnig state or its cpu is preempted, we need wait early in pv_wait_node. After commit "sched/core: Introduce the vcpu_is_preempted(cpu) interface" kernel has knowledge of one vcpu is running or not. So lets use it. Signed-off-by: Pan Xinhui <xinhui@linux

Re: [PATCH v5 2/2] lockd: change the proc_handler for nsm_use_hostnames

for me. Reviewed-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> fs/lockd/svc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c index fc4084e..bd6fcf9 100644 --- a/fs/lockd/svc.c +++ b/fs/lockd/svc.c @@ -561,7 +561,7 @@ static struct ctl_table

Re: [PATCH v5 1/2] sysctl: introduce new proc handler proc_dobool

在 2016/12/15 15:24, Jia He 写道: This is to let bool variable could be correctly displayed in big/little endian sysctl procfs. sizeof(bool) is arch dependent, proc_dobool should work in all arches. Suggested-by: Pan Xinhui <xin...@linux.vnet.ibm.com> Signed-off-by: Jia He <hejia...@

Re: [PATCH v2 1/1] lockd: Change nsm_use_hostnames from bool to u32

hi, jia nice catch! However I think we should fix it totally. This is because do_proc_dointvec_conv() try to get a int value from a bool *. something like below might help. pls. ignore the code style and this is tested :) diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c index

Re: [PATCH v2 0/1] lockd: Change nsm_use_hostnames from bool to u32

在 2016/12/11 23:36, Jia He 写道: nsm_use_hostnames is a module parameter and it will be exported to sysctl procfs. This is to let user sometimes change it from userspace. But the minimal unit for sysctl procfs read/write it sizeof(int). In big endian system, the converting from/to bool to/from

Re: [PATCH v2 1/1] lockd: Change nsm_use_hostnames from bool to u32

在 2016/12/12 01:43, Pan Xinhui 写道: hi, jia nice catch! However I think we should fix it totally. This is because do_proc_dointvec_conv() try to get a int value from a bool *. something like below might help. pls. ignore the code style and this is tested

Re: [PATCH-tip] locking/pvqspinlock: Relax cmpxchg's to improve performance on some archs

在 2016/12/7 03:14, Waiman Long 写道: A number of cmpxchg calls in qspinlock_paravirt.h were replaced by more relaxed versions to improve performance on architectures that use LL/SC. Signed-off-by: Waiman Long --- thanks! I apply it on my tree. and the tests is okay. ke

[PATCH v2] locking/pvqspinlock: Wait early if vCPU is preempted

If prev node is not in runnig state or its vCPU is preempted, we can give up our vCPU slices ASAP in pv_wait_node. After commit d9345c65eb79 ("sched/core: Introduce the vcpu_is_preempted(cpu) interface") kernel has knowledge of one vCPU is running or not. Signed-off-by: Pan Xinh

Re: [PATCH v8 2/6] powerpc: pSeries/Kconfig: Add qspinlock build config

在 2016/12/6 08:58, Boqun Feng 写道: 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@linux.vnet.ibm.com> --- arch/powerpc/platforms/pseries/Kconfig | 8 1 file changed, 8 inse

Re: [PATCH v8 1/6] powerpc/qspinlock: powerpc support qspinlock

correct waiman's address. 在 2016/12/6 08:47, Boqun Feng 写道: On Mon, Dec 05, 2016 at 10:19:21AM -0500, Pan Xinhui wrote: This patch add basic code to enable qspinlock on powerpc. qspinlock is one kind of fairlock implementation. And seen some performance improvement under some scenarios

Re: [PATCH v8 2/6] powerpc: pSeries/Kconfig: Add qspinlock build config

在 2016/12/6 09:24, Pan Xinhui 写道: 在 2016/12/6 08:58, Boqun Feng 写道: 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@linux.vnet.ibm.com> --- arch/powerpc/platforms/pseries/Kconf

[PATCH v8 4/6] powerpc/pv-qspinlock: powerpc support pv-qspinlock

in the hash table might not be the correct lock holder, as for performace issue, we does not take care of hash conflict. Also introduce spin_lock_holder, which tells who owns the lock now. currently the only user is spin_unlock_wait. Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.

[PATCH v8 6/6] powerpc/pv-qspinlock: Optimise native unlock path

Avoid a function call under native version of qspinlock. On powerNV, bafore applying this patch, every unlock is expensive. This small optimizes enhance the performance. We use static_key with jump_label which removes unnecessary loads of lppaca and its stuff. Signed-off-by: Pan Xinhui <xin

[PATCH v8 0/6] Implement qspinlock/pv-qspinlock on ppc

1134.2 = System Benchmarks Index Score 1072.0 1108.91050.6 -------- Pan Xinhui (6): powerpc/qspinlock: powerpc support qspinlock powerpc

[PATCH v8 5/6] powerpc: pSeries: Add pv-qspinlock build config/make

pSeries run as a guest and might need pv-qspinlock. Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> --- arch/powerpc/kernel/Makefile | 1 + arch/powerpc/platforms/pseries/Kconfig | 8 2 files changed, 9 insertions(+) diff --git a/arch/powerpc/kernel/Makefile

[PATCH v8 3/6] powerpc: lib/locks.c: Add cpu yield/wake helper function

will introduce latency and a little overhead. And we do NOT want to suffer any latency on some cases, e.g. in interrupt handler. The second parameter *confer* can indicate such case. __spin_wake_cpu is simpiler, it will wake up one vcpu regardless of its current vcpu state. Signed-off-by: Pan

[PATCH v8 2/6] powerpc: pSeries/Kconfig: Add qspinlock build config

pSeries/powerNV will use qspinlock from now on. Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.com> --- arch/powerpc/platforms/pseries/Kconfig | 8 1 file changed, 8 insertions(+) diff --git a/arch/powerpc/platforms/pseries/Kconfig b/arch/powerpc/platforms/pseries/Kconfig

[PATCH v8 1/6] powerpc/qspinlock: powerpc support qspinlock

endianness system. We override some arch_spin_XXX as powerpc has io_sync stuff which makes sure the io operations are protected by the lock correctly. There is another special case, see commit 2c610022711 ("locking/qspinlock: Fix spin_unlock_wait() some more") Signed-off-by: Pan Xinh

Re: [PATCH] powerpc: cputime: fix a compile warning

在 2016/12/2 12:35, yjin 写道: On 2016年12月02日 12:22, Balbir Singh wrote: On Fri, Dec 2, 2016 at 3:15 PM, Michael Ellerman wrote: yanjiang@windriver.com writes: diff --git a/arch/powerpc/include/asm/cputime.h b/arch/powerpc/include/asm/cputime.h index

[PATCH v9 0/6] Implement qspinlock/pv-qspinlock on ppc

1050.6 ---- Pan Xinhui (6): powerpc/qspinlock: powerpc support qspinlock powerpc: platforms/Kconfig: Add qspinlock build config powerpc: lib/locks.c: Add cpu yield/wake helper function powerpc/pv-qspinlock: powerpc support pv-qspinlo

[PATCH v9 6/6] powerpc/pv-qspinlock: Optimise native unlock path

Avoid a function call under native version of qspinlock. On powerNV, bafore applying this patch, every unlock is expensive. This small optimizes enhance the performance. We use static_key with jump_lable which removes unnecessary loads of lppaca and its stuff. Signed-off-by: Pan Xinhui <xin

[PATCH v9 4/6] powerpc/pv-qspinlock: powerpc support pv-qspinlock

in the hash table might not be the correct lock holder, as for performace issue, we does not take care of hash conflict. Also introduce spin_lock_holder, which tells who owns the lock now. currently the only user is spin_unlock_wait. Signed-off-by: Pan Xinhui <xinhui@linux.vnet.ibm.

[PATCH v9 1/6] powerpc/qspinlock: powerpc support qspinlock

endianness system. We override some arch_spin_XXX as powerpc has io_sync stuff which makes sure the io operations are protected by the lock correctly. There is another special case, see commit 2c610022711 ("locking/qspinlock: Fix spin_unlock_wait() some more") Signed-off-by: Pan Xinh

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