Re: [RFC PATCH] alispinlock: acceleration from lock integration on multi-core platform

[Ling Ma]

Alan,

The attachment  (alispinlock.tar.bz2) in last email includes our
sample cases for spinlock.
The attachment (lock_test.tar.bz2) in this email includes the patch on
kernel 4.3v ,
which has been applied to actual real kernel locks:
when we run the user space program (thread.c) on 72cores E5-2699v3,
it cause many hot kernel spinlocks from __kmalloc and kfree  respectively
with original spinlock cpu cost 25% and  92715428576 cycles after
lock/unlock 1000000 times
with ali spinlock cpu cost 15% and  48475891244 cycles after
lock/unlock 1000000 times.
So we say in the real world workload the ali spinlock improve
performance by 1.9x
(92715428576 cycles/48475891244 cycles)

Thanks
Ling

the

2016-01-12 21:50 GMT+08:00 One Thousand Gnomes <gnomes@xxxxxxxxxxxxxxxxxxx>:
> On Sat, 9 Jan 2016 06:44:15 +0800
> Ling Ma <ling.ma.program@xxxxxxxxx> wrote:
>
>> The attachment (alispinlock.tar.bz2) includes original spinlock and
>> alispinlock ,
>> we compare them on 70 cores based on kernel 4.3, the alispinlock can
>> improve performance upto 3x.
>>
>> the link: https://www.mail-archive.com/linux-kernel@xxxxxxxxxxxxxxx/msg1035940.html
>> indicates when we introduce the idea for real application(user space
>> application  caused the bottle neck from  kernel spinlock )
>> the spinlock performance is improved by 1.9x (perf top -d1 also tell
>> us the spinlock cost time is reduced from 25% to 15%).
>>
>> Appreciate your comments
>
> So this has not been applied to actual real kernel locks (ie converted
> some of the hot kernel locks to it) and then benchmarked with a real
> world workload. This is just for the theoretical locking overhead ?
>
> Alan

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