[PATCH v4 0/5] implement vcpu preempted check

[Pan Xinhui]

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 mahcine type check on ppc, and add config. remove dedicated macro.
>> 	add one patch to drop overload of rwsem_spin_on_owner and mutex_spin_on_owner.
>> 	add more comments
>> 	thanks boqun and Peter's suggestion.
>>
>> This patch set aims to fix lock holder preemption issues.
>>
>> test-case:
>> perf record -a perf bench sched messaging -g 400 -p && perf report
>>
>> 18.09%  sched-messaging  [kernel.vmlinux]  [k] osq_lock
>> 12.28%  sched-messaging  [kernel.vmlinux]  [k] rwsem_spin_on_owner
>>  5.27%  sched-messaging  [kernel.vmlinux]  [k] mutex_unlock
>>  3.89%  sched-messaging  [kernel.vmlinux]  [k] wait_consider_task
>>  3.64%  sched-messaging  [kernel.vmlinux]  [k] _raw_write_lock_irq
>>  3.41%  sched-messaging  [kernel.vmlinux]  [k] mutex_spin_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
>>
>> We also have observed some performace improvements.
>>
>> PPC test result:
>>
>> 1 copy - 0.94%
>> 2 copy - 7.17%
>> 4 copy - 11.9%
>> 8 copy -  3.04%
>> 16 copy - 15.11%
>>
>> details below:
>> Without patch:
>>
>> 1 copy - File Write 4096 bufsize 8000 maxblocks      2188223.0 KBps  (30.0 s, 1 samples)
>> 2 copy - File Write 4096 bufsize 8000 maxblocks      1804433.0 KBps  (30.0 s, 1 samples)
>> 4 copy - File Write 4096 bufsize 8000 maxblocks      1237257.0 KBps  (30.0 s, 1 samples)
>> 8 copy - File Write 4096 bufsize 8000 maxblocks      1032658.0 KBps  (30.0 s, 1 samples)
>> 16 copy - File Write 4096 bufsize 8000 maxblocks       768000.0 KBps  (30.1 s, 1 samples)
>>
>> With patch:
>>
>> 1 copy - File Write 4096 bufsize 8000 maxblocks      2209189.0 KBps  (30.0 s, 1 samples)
>> 2 copy - File Write 4096 bufsize 8000 maxblocks      1943816.0 KBps  (30.0 s, 1 samples)
>> 4 copy - File Write 4096 bufsize 8000 maxblocks      1405591.0 KBps  (30.0 s, 1 samples)
>> 8 copy - File Write 4096 bufsize 8000 maxblocks      1065080.0 KBps  (30.0 s, 1 samples)
>> 16 copy - File Write 4096 bufsize 8000 maxblocks       904762.0 KBps  (30.0 s, 1 samples)
>>
>> X86 test result:
>> 	test-case			after-patch	  before-patch
>> Execl Throughput                       |    18307.9 lps  |    11701.6 lps
>> File Copy 1024 bufsize 2000 maxblocks  |  1352407.3 KBps |   790418.9 KBps
>> File Copy 256 bufsize 500 maxblocks    |   367555.6 KBps |   222867.7 KBps
>> File Copy 4096 bufsize 8000 maxblocks  |  3675649.7 KBps |  1780614.4 KBps
>> Pipe Throughput                        | 11872208.7 lps  | 11855628.9 lps
>> Pipe-based Context Switching           |  1495126.5 lps  |  1490533.9 lps
>> Process Creation                       |    29881.2 lps  |    28572.8 lps
>> Shell 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
>>
>> Pan Xinhui (5):
>>   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, kvm: support vcpu preempted check
>
> The attached patch adds Xen support for x86. Please tell me whether you
> want to add this patch to your series or if I should post it when your
> series has been accepted.
>
hi, Juergen
	Your patch is pretty small and nice :) thanks!
I can include your patch into my next patchset after this patchset reviewed. :)


> You can add my
>
> Tested-by: Juergen Gross <jgross at suse.com>
>
> for patches 1-3 and 5 (paravirt parts only).
>

Thanks a lot!

xinhui

>
> Juergen
>
>>
>>  arch/powerpc/include/asm/spinlock.h   |  8 ++++++++
>>  arch/x86/include/asm/paravirt_types.h |  6 ++++++
>>  arch/x86/include/asm/spinlock.h       |  8 ++++++++
>>  arch/x86/include/uapi/asm/kvm_para.h  |  3 ++-
>>  arch/x86/kernel/kvm.c                 | 11 +++++++++++
>>  arch/x86/kernel/paravirt.c            | 11 +++++++++++
>>  arch/x86/kvm/x86.c                    | 12 ++++++++++++
>>  include/linux/sched.h                 | 12 ++++++++++++
>>  kernel/locking/mutex.c                | 15 +++++++++++++--
>>  kernel/locking/osq_lock.c             | 10 +++++++++-
>>  kernel/locking/rwsem-xadd.c           | 16 +++++++++++++---
>>  11 files changed, 105 insertions(+), 7 deletions(-)
>>
>