在 2017/2/21 09:58, Guilherme G. Piccoli 写道:
Currently the xmon debugger is set only via kernel boot command-line.
It's disabled by default, and can be enabled with "xmon=on" on the
command-line. Also, xmon may be accessed via sysrq mechanism.
But we cannot enable/disable xmon in runtime, it nee
在 2017/2/17 14:05, Michael Ellerman 写道:
Pan Xinhui 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;
#endif /* CONFIG_SMP */
static
在 2017/2/16 18:57, Guilherme G. Piccoli 写道:
On 16/02/2017 03:09, Michael Ellerman wrote:
Pan Xinhui 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 interrut
fail to dump. So keep xmon in its
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
---
arch/powerpc/xmon/xmon.c | 5 -
1 file changed, 4
在 2017/2/14 10:35, Nicholas Piggin 写道:
On Mon, 13 Feb 2017 19:00:42 -0200
"Guilherme G. Piccoli" wrote:
Currently the xmon debugger is set only via kernel boot command-line.
It's disabled by default, and can be enabled with "xmon=on" on the
command-line. Also, xmon may be accessed via sysrq
'x|X' exit commands. Turn xmon off if 'z'
is following.
Signed-off-by: Pan Xinhui
---
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 100644
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
pSeries run as a guest and might need pv-qspinlock.
Signed-off-by: Pan Xinhui
---
arch/powerpc/kernel/Makefile | 1 +
arch/powerpc/platforms/pseries/Kconfig | 8
2 files changed, 9 insertions(+)
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index
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
---
arch/powerpc/include/asm
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
pSeries/powerNV will use qspinlock from now on.
Signed-off-by: Pan Xinhui
---
arch/powerpc/platforms/Kconfig | 9 +
1 file changed, 9 insertions(+)
diff --git a/arch/powerpc/platforms/Kconfig b/arch/powerpc/platforms/Kconfig
index fbdae83..3559bbf 100644
--- a/arch/powerpc/platforms
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 Xinhui
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
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
---
arch/powerpc/platforms/pseries/Kconfig | 8
1 file changed, 8 insertions
在 2016/12/6 09:23, Boqun Feng 写道:
On Mon, Dec 05, 2016 at 10:19:23AM -0500, Pan Xinhui wrote:
Add two corresponding helper functions to support pv-qspinlock.
For normal use, __spin_yield_cpu will confer current vcpu slices to the
target vcpu(say, a lock holder). If target vcpu is not
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
---
arch/powerpc/platforms/pseries/Kconfig | 8
1 file changed, 8 insertions(+)
diff --git a/arch/powerpc
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 scen
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
pSeries run as a guest and might need pv-qspinlock.
Signed-off-by: Pan Xinhui
---
arch/powerpc/kernel/Makefile | 1 +
arch/powerpc/platforms/pseries/Kconfig | 8
2 files changed, 9 insertions(+)
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index
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
---
arch/powerpc/include/asm
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
pSeries/powerNV will use qspinlock from now on.
Signed-off-by: Pan Xinhui
---
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
index bec90fb..8a87d06 100644
--- a
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 Xinhui
1134.2
=
System Benchmarks Index Score 1072.0 1108.91050.6
--------
Pan Xinhui (6):
powerpc/qspinlock: powerpc support qspinlock
powerpc
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 4f60db0..4423e97 100644
--- a/arch/p
在 2016/11/25 11:07, Michael Ellerman 写道:
In commit d0563a1297e2 ("powerpc: Implement {cmp}xchg for u8 and u16")
we removed the volatile from __cmpxchg().
This is leading to warnings such as:
drivers/gpu/drm/drm_lock.c: In function ‘drm_lock_take’:
arch/powerpc/include/asm/cmpxchg.h:484:37
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*/
if
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
u has been preempted.
Signed-off-by: Pan Xinhui
Acked-by: Radim Krčmář
Acked-by: Paolo Bonzini
---
Documentation/virtual/kvm/msr.txt | 9 -
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/Documentation/virtual/kvm/msr.txt
b/Documentation/virtual/kvm/msr.txt
index 2a71c8f..
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
Signed-off-by: Pan Xinhui
---
arch/x86/xen/spinlock.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/ar
concurrent) | 3531.4 lpm | 3211.9 lpm
System Call Overhead | 10385653.0 lps | 10419979.0 lps
Signed-off-by: Pan Xinhui
Acked-by: Paolo Bonzini
---
arch/x86/kernel/kvm.c | 12
1 file changed, 12 insertions(+)
diff --git a/arch/x86/kernel/kvm.c
kvm_steal_time ::preempted to indicate that if
one vcpu is running or not.
Signed-off-by: Pan Xinhui
Acked-by: Paolo Bonzini
---
arch/x86/include/uapi/asm/kvm_para.h | 4 +++-
arch/x86/kvm/x86.c | 16
2 files changed, 19 insertions(+), 1 deletion(-)
diff --git a
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
Acked-by: Paolo Bonzini
---
include/linux/kvm_host.h | 2 ++
virt/kvm
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
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 moving the
CIF_ENABLED_WAIT
->yiled_count keeps zero on
PowerNV. So we can just skip the machine type check.
Suggested-by: Boqun Feng
Suggested-by: Peter Zijlstra (Intel)
Signed-off-by: Pan Xinhui
---
arch/powerpc/include/asm/spinlock.h | 8
1 file changed, 8 insertions(+)
diff --git a/arch/powerpc/include/asm/spinloc
essaging [kernel.vmlinux] [k] system_call
2.69% sched-messaging [kernel.vmlinux] [k] wait_consider_task
Signed-off-by: Pan Xinhui
Acked-by: Christian Borntraeger
Acked-by: Paolo Bonzini
Tested-by: Juergen Gross
---
kernel/locking/mutex.c | 13 +++--
kernel/locking/rwsem-xad
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
Signed-off-by: Pan Xinhui
Acked-by: Christian Borntraeger
Acked-by: Pa
.
Suggested-by: Peter Zijlstra (Intel)
Signed-off-by: Pan Xinhui
Acked-by: Christian Borntraeger
Acked-by: Paolo Bonzini
Tested-by: Juergen Gross
---
include/linux/sched.h | 12
1 file changed, 12 insertions(+)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index
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 (9):
kernel/sched: introduce vcpu preempted check interface
locking/
在 2016/10/30 00:52, Davidlohr Bueso 写道:
On Fri, 28 Oct 2016, Pan Xinhui wrote:
/*
* If we need to reschedule bail... so we can block.
+ * Use vcpu_is_preempted to detech lock holder preemption issue
^^ detect
ok. thanks for
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
在 2016/10/29 03:43, Konrad Rzeszutek Wilk 写道:
On Fri, Oct 28, 2016 at 04:11:26AM -0400, Pan Xinhui wrote:
From: Juergen Gross
Support the vcpu_is_preempted() functionality under Xen. This will
enhance lock performance on overcommitted hosts (more runnable vcpus
than physical cpus in the
u has been preempted.
Signed-off-by: Pan Xinhui
Acked-by: Radim Krčmář
---
Documentation/virtual/kvm/msr.txt | 9 -
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/Documentation/virtual/kvm/msr.txt
b/Documentation/virtual/kvm/msr.txt
index 2a71c8f..ab2ab76 100644
--- a/Docum
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
Signed-off-by: Pan Xinhui
---
arch/x86/xen/spinlock.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/ar
concurrent) | 3531.4 lpm | 3211.9 lpm
System Call Overhead | 10385653.0 lps | 10419979.0 lps
Signed-off-by: Pan Xinhui
---
arch/x86/kernel/kvm.c | 12
1 file changed, 12 insertions(+)
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
ind
kvm_steal_time ::preempted to indicate that if
one vcpu is running or not.
Signed-off-by: Pan Xinhui
---
arch/x86/include/uapi/asm/kvm_para.h | 4 +++-
arch/x86/kvm/x86.c | 16
2 files changed, 19 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/uapi
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
---
include/linux/kvm_host.h | 2 ++
virt/kvm/kvm_main.c | 20
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
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 moving the
CIF_ENABLED_WAIT
->yiled_count keeps zero on
powerNV. So we can just skip the machine type check.
Suggested-by: Boqun Feng
Suggested-by: Peter Zijlstra (Intel)
Signed-off-by: Pan Xinhui
---
arch/powerpc/include/asm/spinlock.h | 8
1 file changed, 8 insertions(+)
diff --git a/arch/powerpc/include/
essaging [kernel.vmlinux] [k] system_call
2.69% sched-messaging [kernel.vmlinux] [k] wait_consider_task
Signed-off-by: Pan Xinhui
Acked-by: Christian Borntraeger
Tested-by: Juergen Gross
---
kernel/locking/mutex.c | 15 +--
kernel/locking/rwsem-xadd.c | 16 +---
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
Signed-off-by: Pan Xinhui
Acked-by: Christian Borntraeger
Tested-by: Ju
.
Suggested-by: Peter Zijlstra (Intel)
Signed-off-by: Pan Xinhui
Acked-by: Christian Borntraeger
Tested-by: Juergen Gross
---
include/linux/sched.h | 12
1 file changed, 12 insertions(+)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 348f51b..44c1ce7 100644
0419979.0 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 overl
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, &vcpu->arch.st.stime,
+
在 2016/10/21 09:23, Boqun Feng 写道:
On Thu, Oct 20, 2016 at 05:27:54PM -0400, Pan Xinhui wrote:
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) s
n preempted.
Signed-off-by: Pan Xinhui
---
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/Documentation/virtual/kvm/msr.txt
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 moving the
CIF_ENABLED_WAIT
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
Signed-off-by: Pan Xinhui
---
arch/x86/xen/spinlock.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/ar
Call Overhead | 10385653.0 lps | 10419979.0 lps
Signed-off-by: Pan Xinhui
---
arch/x86/include/uapi/asm/kvm_para.h | 3 ++-
arch/x86/kernel/kvm.c| 12
arch/x86/kvm/x86.c | 18 ++
3 files changed, 32 insertions(+), 1
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
->yiled_count keeps zero on
powerNV. So we can just skip the machine type check.
Suggested-by: Boqun Feng
Suggested-by: Peter Zijlstra (Intel)
Signed-off-by: Pan Xinhui
---
arch/powerpc/include/asm/spinlock.h | 8
1 file changed, 8 insertions(+)
diff --git a/arch/powerpc/include/
essaging [kernel.vmlinux] [k] system_call
2.69% sched-messaging [kernel.vmlinux] [k] wait_consider_task
Signed-off-by: Pan Xinhui
Acked-by: Christian Borntraeger
Tested-by: Juergen Gross
---
kernel/locking/mutex.c | 15 +--
kernel/locking/rwsem-xadd.c | 16 +---
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
Signed-off-by: Pan Xinhui
Acked-by: Christian Borntraeger
Tested-by: Ju
.
Suggested-by: Peter Zijlstra (Intel)
Signed-off-by: Pan Xinhui
Acked-by: Christian Borntraeger
Tested-by: Juergen Gross
---
include/linux/sched.h | 12
1 file changed, 12 insertions(+)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 348f51b..44c1ce7 100644
ll 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/sch
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 as
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
在 2016/10/19 14:47, Christian Borntraeger 写道:
On 10/19/2016 12:20 PM, Pan Xinhui wrote:
change from v3:
add x86 vcpu preempted check patch
If you want you could add the s390 patch that I provided for your last version.
I also gave my Acked-by for all previous patches.
hi
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
---
arch/x86/include/asm/paravirt_types.h | 6
->yiled_count keeps zero on
powerNV. So we can just skip the machine type check.
Suggested-by: Boqun Feng
Suggested-by: Peter Zijlstra (Intel)
Signed-off-by: Pan Xinhui
---
arch/powerpc/include/asm/spinlock.h | 8
1 file changed, 8 insertions(+)
diff --git a/arch/powerpc/include/
essaging [kernel.vmlinux] [k] system_call
2.69% sched-messaging [kernel.vmlinux] [k] wait_consider_task
Signed-off-by: Pan Xinhui
---
kernel/locking/mutex.c | 15 +--
kernel/locking/rwsem-xadd.c | 16 +---
2 files changed, 26 insertions(+), 5 deletions(-)
diff --git
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
Signed-off-by: Pan Xinhui
---
kernel/locking/osq_lock.c | 10 +-
1 f
(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
Pan Xinhui (5):
kernel/sched: introduce vcpu preempted check interface
locking/osq: Drop
.
Suggested-by: Peter Zijlstra (Intel)
Signed-off-by: Pan Xinhui
---
include/linux/sched.h | 12
1 file changed, 12 insertions(+)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 348f51b..44c1ce7 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
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,
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 availab
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
在 2016/9/29 18:10, Peter Zijlstra 写道:
On Thu, Jul 21, 2016 at 07:45:10AM -0400, Pan Xinhui wrote:
change from v2:
no code change, fix typos, update some comments
change from v1:
a simplier definition of default vcpu_is_preempted
skip mahcine type check on ppc, and add
pSeries run as a guest and might need pv-qspinlock.
Signed-off-by: Pan Xinhui
---
arch/powerpc/kernel/Makefile | 1 +
arch/powerpc/platforms/pseries/Kconfig | 8
2 files changed, 9 insertions(+)
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index
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
---
arch/powerpc/include/asm
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
pseries will use qspinlock by default.
Signed-off-by: Pan Xinhui
---
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..f669323 100644
--- a/arch/powerpc
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 Xinh
ed-by: Boqun Feng
Signed-off-by: Pan Xinhui
---
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 8a99abf..ce655aa 100644
--- a/kernel/locking/qspinlock_parav
1008.3 1122.61134.2
=
System Benchmarks Index Score 1072.0 1108.91050.6
--------
Pan Xinhui (6):
pv-qspin
nterface 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 v
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
Signed-off-by: Pan Xinhui
---
kernel/locking/osq_lock.c | 10 +-
1 f
essaging [kernel.vmlinux] [k] system_call
2.69% sched-messaging [kernel.vmlinux] [k] wait_consider_task
Signed-off-by: Pan Xinhui
---
kernel/locking/mutex.c | 15 +--
kernel/locking/rwsem-xadd.c | 16 +---
2 files changed, 26 insertions(+), 5 deletions(-)
diff --git
->yield_count keeps zero on
powerNV. So we can just skip the machine type check.
Suggested-by: Boqun Feng
Suggested-by: Peter Zijlstra (Intel)
Signed-off-by: Pan Xinhui
---
arch/powerpc/include/asm/spinlock.h | 18 ++
1 file changed, 18 insertions(+)
diff --git a/arch/powerpc/incl
check.
Suggested-by: Peter Zijlstra (Intel)
Signed-off-by: Pan Xinhui
---
include/linux/sched.h | 12
1 file changed, 12 insertions(+)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 6e42ada..cbe0574 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
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
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
Signed-off-by: Pan Xinhui
---
kernel/locking/osq_lock.c | 10 +-
1 f
essaging [kernel.vmlinux] [k] system_call
2.69% sched-messaging [kernel.vmlinux] [k] wait_consider_task
Signed-off-by: Pan Xinhui
---
kernel/locking/mutex.c | 15 +--
kernel/locking/rwsem-xadd.c | 16 +---
2 files changed, 26 insertions(+), 5 deletions(-)
diff --git
->yiled_count keeps zero on
powerNV. So we can just skip the machine type.
Suggested-by: Boqun Feng
Suggested-by: Peter Zijlstra (Intel)
Signed-off-by: Pan Xinhui
---
arch/powerpc/include/asm/spinlock.h | 18 ++
1 file changed, 18 insertions(+)
diff --git a/arch/powerpc/include/
.
Suggested-by: Peter Zijlstra (Intel)
Signed-off-by: Pan Xinhui
---
include/linux/sched.h | 12
1 file changed, 12 insertions(+)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 6e42ada..cbe0574 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
] 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 ch
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/
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
---
kernel/locking/osq_lock.c | 16 +++-
1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/ker
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