lkml.org 
[lkml]   [2016]   [Apr]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] powerpc: introduce {cmp}xchg for u8 and u16
On 04/13/2016 07:15 AM, Pan Xinhui wrote:
> Hello Peter,
>
> On 2016年04月12日 22:30, Peter Zijlstra wrote:
>
>>> I am working on the qspinlock implementation on PPC.
>>> Your and Waiman's patches are so nice. :)
>> Thanks!, last time I looked at PPC spinlocks they could not use things
>> like ticket locks because PPC might be a guest and fairness blows etc..
>>
>> You're making the qspinlock-paravirt thing work on PPC, or doing
>> qspinlock only for bare-metal PPC?
>>
> I am making the both work. :)
> qspinlock works on PPC now. I am preparing the patches and will send them out in next weeks :)

What of performance improvement are you seeing in PPC?

> The paravirt work is a little hard.
> currently, there are pv_wait() and pv_kick(). but only pv_kick has the parameter cpu(who will hold the lock as soon as the lock is unlocked).
> We need parameter cpu(who holds the lock now) in pv_wait,too.

That can be doable to a certain extent. However, if the current lock
holder acquired the lock via the fastpath only. The CPU information is
not logged anywhere. For a contended lock, the information should be there.

Cheers,
Longman

\
 
 \ /
  Last update: 2016-04-13 18:01    [W:1.266 / U:0.084 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site