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

Pan Xinhui
2016-10-19T17:08:02Z

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@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(-)
>>
>

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