Re: [PATCH 11/17] powerpc/qspinlock: allow propagation of yield CPU down the queue

2022-11-10 Thread Nicholas Piggin
On Thu Nov 10, 2022 at 10:42 AM AEST, Jordan Niethe wrote: > On Thu, 2022-07-28 at 16:31 +1000, Nicholas Piggin wrote: > [resend as utf-8, not utf-7] > > Having all CPUs poll the lock word for the owner CPU that should be > > yielded to defeats most of the purpose of using MCS queueing for > >

Re: [PATCH 11/17] powerpc/qspinlock: allow propagation of yield CPU down the queue

2022-11-09 Thread Jordan Niethe
On Thu, 2022-07-28 at 16:31 +1000, Nicholas Piggin wrote: [resend as utf-8, not utf-7] > Having all CPUs poll the lock word for the owner CPU that should be > yielded to defeats most of the purpose of using MCS queueing for > scalability. Yet it may be desirable for queued waiters to to yield > to

Re: [PATCH 11/17] powerpc/qspinlock: allow propagation of yield CPU down the queue

2022-10-06 Thread Laurent Dufour
On 28/07/2022 08:31:14, Nicholas Piggin wrote: > Having all CPUs poll the lock word for the owner CPU that should be > yielded to defeats most of the purpose of using MCS queueing for > scalability. Yet it may be desirable for queued waiters to to yield > to a preempted owner. > > s390 addreses

Re: [PATCH 11/17] powerpc/qspinlock: allow propagation of yield CPU down the queue

2022-08-11 Thread Jordan Niethe
On Thu, 2022-07-28 at 16:31 +1000, Nicholas Piggin wrote: > Having all CPUs poll the lock word for the owner CPU that should be > yielded to defeats most of the purpose of using MCS queueing for > scalability. Yet it may be desirable for queued waiters to to yield > to a preempted owner. > > s390

[PATCH 11/17] powerpc/qspinlock: allow propagation of yield CPU down the queue

2022-07-28 Thread Nicholas Piggin
Having all CPUs poll the lock word for the owner CPU that should be yielded to defeats most of the purpose of using MCS queueing for scalability. Yet it may be desirable for queued waiters to to yield to a preempted owner. s390 addreses this problem by having queued waiters sample the lock word