From: Waiman Long <longman@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>,
Nicholas Piggin <npiggin@gmail.com>,
linuxppc-dev@lists.ozlabs.org, Will Deacon <will@kernel.org>,
Boqun Feng <boqun.feng@gmail.com>, Ingo Molnar <mingo@redhat.com>,
Anton Blanchard <anton@ozlabs.org>,
linux-kernel@vger.kernel.org,
virtualization@lists.linux-foundation.org,
kvm-ppc@vger.kernel.org, linux-arch@vger.kernel.org
Subject: Re: [PATCH v3 5/6] powerpc/pseries: implement paravirt qspinlocks for SPLPAR
Date: Thu, 23 Jul 2020 14:32:36 -0400 [thread overview]
Message-ID: <845de183-56f5-2958-3159-faa131d46401@redhat.com> (raw)
In-Reply-To: <20200723140011.GR5523@worktop.programming.kicks-ass.net>
On 7/23/20 10:00 AM, Peter Zijlstra wrote:
> On Thu, Jul 09, 2020 at 12:06:13PM -0400, Waiman Long wrote:
>> We don't really need to do a pv_spinlocks_init() if pv_kick() isn't
>> supported.
> Waiman, if you cannot explain how not having kick is a sane thing, what
> are you saying here?
>
The current PPC paravirt spinlock code doesn't do any cpu kick. It does
an equivalence of pv_wait by yielding the cpu to the lock holder only.
The pv_spinlocks_init() is for setting up the hash table for doing
pv_kick. If we don't need to do pv_kick, we don't need the hash table.
I am not saying that pv_kick is not needed for the PPC environment. I
was just trying to adapt the pvqspinlock code to such an environment
first. Further investigation on how to implement some kind of pv_kick
will be something that we may want to do as a follow on.
BTW, do you have any comment on my v2 lock holder cpu info qspinlock
patch? I will have to update the patch to fix the reported 0-day test
problem, but I want to collect other feedback before sending out v3.
Cheers,
Longman
WARNING: multiple messages have this Message-ID (diff)
From: Waiman Long <longman@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: linux-arch@vger.kernel.org, Boqun Feng <boqun.feng@gmail.com>,
virtualization@lists.linux-foundation.org,
linuxppc-dev@lists.ozlabs.org,
Nicholas Piggin <npiggin@gmail.com>,
linux-kernel@vger.kernel.org, Ingo Molnar <mingo@redhat.com>,
kvm-ppc@vger.kernel.org, Will Deacon <will@kernel.org>
Subject: Re: [PATCH v3 5/6] powerpc/pseries: implement paravirt qspinlocks for SPLPAR
Date: Thu, 23 Jul 2020 14:32:36 -0400 [thread overview]
Message-ID: <845de183-56f5-2958-3159-faa131d46401@redhat.com> (raw)
In-Reply-To: <20200723140011.GR5523@worktop.programming.kicks-ass.net>
On 7/23/20 10:00 AM, Peter Zijlstra wrote:
> On Thu, Jul 09, 2020 at 12:06:13PM -0400, Waiman Long wrote:
>> We don't really need to do a pv_spinlocks_init() if pv_kick() isn't
>> supported.
> Waiman, if you cannot explain how not having kick is a sane thing, what
> are you saying here?
>
The current PPC paravirt spinlock code doesn't do any cpu kick. It does
an equivalence of pv_wait by yielding the cpu to the lock holder only.
The pv_spinlocks_init() is for setting up the hash table for doing
pv_kick. If we don't need to do pv_kick, we don't need the hash table.
I am not saying that pv_kick is not needed for the PPC environment. I
was just trying to adapt the pvqspinlock code to such an environment
first. Further investigation on how to implement some kind of pv_kick
will be something that we may want to do as a follow on.
BTW, do you have any comment on my v2 lock holder cpu info qspinlock
patch? I will have to update the patch to fix the reported 0-day test
problem, but I want to collect other feedback before sending out v3.
Cheers,
Longman
WARNING: multiple messages have this Message-ID (diff)
From: Waiman Long <longman@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>,
Nicholas Piggin <npiggin@gmail.com>,
linuxppc-dev@lists.ozlabs.org, Will Deacon <will@kernel.org>,
Boqun Feng <boqun.feng@gmail.com>, Ingo Molnar <mingo@redhat.com>,
Anton Blanchard <anton@ozlabs.org>,
linux-kernel@vger.kernel.org,
virtualization@lists.linux-foundation.org,
kvm-ppc@vger.kernel.org, linux-arch@vger.kernel.org
Subject: Re: [PATCH v3 5/6] powerpc/pseries: implement paravirt qspinlocks for SPLPAR
Date: Thu, 23 Jul 2020 18:32:36 +0000 [thread overview]
Message-ID: <845de183-56f5-2958-3159-faa131d46401@redhat.com> (raw)
In-Reply-To: <20200723140011.GR5523@worktop.programming.kicks-ass.net>
On 7/23/20 10:00 AM, Peter Zijlstra wrote:
> On Thu, Jul 09, 2020 at 12:06:13PM -0400, Waiman Long wrote:
>> We don't really need to do a pv_spinlocks_init() if pv_kick() isn't
>> supported.
> Waiman, if you cannot explain how not having kick is a sane thing, what
> are you saying here?
>
The current PPC paravirt spinlock code doesn't do any cpu kick. It does
an equivalence of pv_wait by yielding the cpu to the lock holder only.
The pv_spinlocks_init() is for setting up the hash table for doing
pv_kick. If we don't need to do pv_kick, we don't need the hash table.
I am not saying that pv_kick is not needed for the PPC environment. I
was just trying to adapt the pvqspinlock code to such an environment
first. Further investigation on how to implement some kind of pv_kick
will be something that we may want to do as a follow on.
BTW, do you have any comment on my v2 lock holder cpu info qspinlock
patch? I will have to update the patch to fix the reported 0-day test
problem, but I want to collect other feedback before sending out v3.
Cheers,
Longman
next prev parent reply other threads:[~2020-07-23 18:32 UTC|newest]
Thread overview: 153+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-06 4:35 [PATCH v3 0/6] powerpc: queued spinlocks and rwlocks Nicholas Piggin
2020-07-06 4:35 ` Nicholas Piggin
2020-07-06 4:35 ` Nicholas Piggin
2020-07-06 4:35 ` [PATCH v3 1/6] powerpc/powernv: must include hvcall.h to get PAPR defines Nicholas Piggin
2020-07-06 4:35 ` Nicholas Piggin
2020-07-06 4:35 ` Nicholas Piggin
2020-07-09 10:05 ` Michael Ellerman
2020-07-09 10:05 ` Michael Ellerman
2020-07-09 10:05 ` Michael Ellerman
2020-07-09 10:05 ` Michael Ellerman
2020-07-09 10:05 ` Michael Ellerman
2020-07-06 4:35 ` [PATCH v3 2/6] powerpc/pseries: move some PAPR paravirt functions to their own file Nicholas Piggin
2020-07-06 4:35 ` Nicholas Piggin
2020-07-06 4:35 ` Nicholas Piggin
2020-07-09 10:11 ` Michael Ellerman
2020-07-09 10:11 ` Michael Ellerman
2020-07-09 10:11 ` Michael Ellerman
2020-07-09 10:11 ` Michael Ellerman
2020-07-09 10:11 ` Michael Ellerman
2020-07-06 4:35 ` [PATCH v3 3/6] powerpc: move spinlock implementation to simple_spinlock Nicholas Piggin
2020-07-06 4:35 ` Nicholas Piggin
2020-07-06 4:35 ` Nicholas Piggin
2020-07-09 10:15 ` Michael Ellerman
2020-07-09 10:15 ` Michael Ellerman
2020-07-09 10:15 ` Michael Ellerman
2020-07-09 10:15 ` Michael Ellerman
2020-07-09 10:15 ` Michael Ellerman
2020-07-06 4:35 ` [PATCH v3 4/6] powerpc/64s: implement queued spinlocks and rwlocks Nicholas Piggin
2020-07-06 4:35 ` Nicholas Piggin
2020-07-06 4:35 ` Nicholas Piggin
2020-07-09 10:20 ` Michael Ellerman
2020-07-09 10:20 ` Michael Ellerman
2020-07-09 10:20 ` Michael Ellerman
2020-07-09 10:20 ` Michael Ellerman
2020-07-09 10:20 ` Michael Ellerman
2020-07-09 10:33 ` Peter Zijlstra
2020-07-09 10:33 ` Peter Zijlstra
2020-07-09 10:33 ` Peter Zijlstra
2020-07-23 14:37 ` Michal Suchánek
2020-07-23 14:37 ` Michal Suchánek
2020-07-23 14:37 ` Michal Suchánek
2020-07-06 4:35 ` [PATCH v3 5/6] powerpc/pseries: implement paravirt qspinlocks for SPLPAR Nicholas Piggin
2020-07-06 4:35 ` Nicholas Piggin
2020-07-06 4:35 ` Nicholas Piggin
2020-07-09 10:53 ` Michael Ellerman
2020-07-09 10:53 ` Michael Ellerman
2020-07-09 10:53 ` Michael Ellerman
2020-07-09 10:53 ` Michael Ellerman
2020-07-09 10:53 ` Michael Ellerman
2020-07-09 11:03 ` Peter Zijlstra
2020-07-09 11:03 ` Peter Zijlstra
2020-07-09 11:03 ` Peter Zijlstra
2020-07-09 16:06 ` Waiman Long
2020-07-09 16:06 ` Waiman Long
2020-07-09 16:06 ` Waiman Long
2020-07-23 14:00 ` Peter Zijlstra
2020-07-23 14:00 ` Peter Zijlstra
2020-07-23 14:00 ` Peter Zijlstra
2020-07-23 18:32 ` Waiman Long [this message]
2020-07-23 18:32 ` Waiman Long
2020-07-23 18:32 ` Waiman Long
2020-07-23 18:47 ` peterz
2020-07-23 18:47 ` peterz
2020-07-23 18:47 ` peterz
2020-07-23 18:47 ` peterz
2020-07-23 19:04 ` Waiman Long
2020-07-23 19:04 ` Waiman Long
2020-07-23 19:04 ` Waiman Long
2020-07-23 19:58 ` peterz
2020-07-23 19:58 ` peterz
2020-07-23 19:58 ` peterz
2020-07-23 20:30 ` Segher Boessenkool
2020-07-23 20:30 ` Segher Boessenkool
2020-07-23 20:30 ` Segher Boessenkool
2020-07-23 21:58 ` Waiman Long
2020-07-23 21:58 ` Waiman Long
2020-07-23 21:58 ` Waiman Long
2020-07-24 8:16 ` Will Deacon
2020-07-24 8:16 ` Will Deacon
2020-07-24 8:16 ` Will Deacon
2020-07-24 19:10 ` Waiman Long
2020-07-24 19:10 ` Waiman Long
2020-07-24 19:10 ` Waiman Long
2020-07-25 3:02 ` Waiman Long
2020-07-25 3:02 ` Waiman Long
2020-07-25 3:02 ` Waiman Long
2020-07-25 17:26 ` Peter Zijlstra
2020-07-25 17:26 ` Peter Zijlstra
2020-07-25 17:26 ` Peter Zijlstra
2020-07-25 17:26 ` Peter Zijlstra
2020-07-25 17:36 ` Waiman Long
2020-07-25 17:36 ` Waiman Long
2020-07-25 17:36 ` Waiman Long
2020-07-23 14:09 ` Nicholas Piggin
2020-07-23 14:09 ` Nicholas Piggin
2020-07-23 14:09 ` Nicholas Piggin
2020-07-06 4:35 ` [PATCH v3 6/6] powerpc/qspinlock: optimised atomic_try_cmpxchg_lock that adds the lock hint Nicholas Piggin
2020-07-06 4:35 ` Nicholas Piggin
2020-07-06 4:35 ` Nicholas Piggin
2020-07-06 18:39 ` [PATCH v3 0/6] powerpc: queued spinlocks and rwlocks Waiman Long
2020-07-06 18:39 ` Waiman Long
2020-07-06 18:39 ` Waiman Long
2020-07-07 5:57 ` Nicholas Piggin
2020-07-07 5:57 ` Nicholas Piggin
2020-07-07 5:57 ` Nicholas Piggin
2020-07-08 3:33 ` Waiman Long
2020-07-08 3:33 ` Waiman Long
2020-07-08 3:33 ` Waiman Long
2020-07-08 5:10 ` Nicholas Piggin
2020-07-08 5:10 ` Nicholas Piggin
2020-07-08 5:10 ` Nicholas Piggin
2020-07-08 23:50 ` Waiman Long
2020-07-08 23:50 ` Waiman Long
2020-07-08 23:50 ` Waiman Long
2020-07-08 23:58 ` Waiman Long
2020-07-08 23:58 ` Waiman Long
2020-07-08 23:58 ` Waiman Long
2020-07-08 8:32 ` Peter Zijlstra
2020-07-08 8:32 ` Peter Zijlstra
2020-07-08 8:32 ` Peter Zijlstra
2020-07-08 8:32 ` Peter Zijlstra
2020-07-08 23:53 ` Waiman Long
2020-07-08 23:53 ` Waiman Long
2020-07-08 23:53 ` Waiman Long
2020-07-08 8:41 ` Peter Zijlstra
2020-07-08 8:41 ` Peter Zijlstra
2020-07-08 8:41 ` Peter Zijlstra
2020-07-08 23:54 ` Waiman Long
2020-07-08 23:54 ` Waiman Long
2020-07-08 23:54 ` Waiman Long
2020-07-09 8:31 ` Peter Zijlstra
2020-07-09 8:31 ` Peter Zijlstra
2020-07-09 8:31 ` Peter Zijlstra
2020-07-09 8:31 ` Peter Zijlstra
2020-07-21 11:20 ` Nicholas Piggin
2020-07-21 11:20 ` Nicholas Piggin
2020-07-21 11:20 ` Nicholas Piggin
2020-07-21 11:08 ` Nicholas Piggin
2020-07-21 11:08 ` Nicholas Piggin
2020-07-21 11:08 ` Nicholas Piggin
2020-07-21 11:08 ` Nicholas Piggin
2020-07-21 14:36 ` Waiman Long
2020-07-21 14:36 ` Waiman Long
2020-07-21 14:36 ` Waiman Long
2020-07-23 13:30 ` Nicholas Piggin
2020-07-23 13:30 ` Nicholas Piggin
2020-07-23 13:30 ` Nicholas Piggin
2020-07-23 14:29 ` Waiman Long
2020-07-23 14:29 ` Waiman Long
2020-07-23 14:29 ` Waiman Long
2020-07-23 16:12 ` Nicholas Piggin
2020-07-23 16:12 ` Nicholas Piggin
2020-07-23 16:12 ` Nicholas Piggin
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