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From: Guo Ren <guoren@kernel.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Alex Kogan <alex.kogan@oracle.com>,
	linux@armlinux.org.uk, mingo@redhat.com, will.deacon@arm.com,
	arnd@arndb.de, longman@redhat.com, linux-arch@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, tglx@linutronix.de, bp@alien8.de,
	hpa@zytor.com, x86@kernel.org, guohanjun@huawei.com,
	jglauber@marvell.com, steven.sistare@oracle.com,
	daniel.m.jordan@oracle.com, dave.dice@oracle.com
Subject: Re: [PATCH v15 3/6] locking/qspinlock: Introduce CNA into the slow path of qspinlock
Date: Thu, 3 Aug 2023 18:28:51 +0800	[thread overview]
Message-ID: <CAJF2gTQFZEpHK45hd9HXxHxJc4gaCuDQ4wZ2adDzHwGQjA6VFw@mail.gmail.com> (raw)
In-Reply-To: <20230803085004.GF212435@hirez.programming.kicks-ass.net>

On Thu, Aug 3, 2023 at 4:50 PM Peter Zijlstra <peterz@infradead.org> wrote:
>
> On Wed, Aug 02, 2023 at 07:14:05PM -0400, Guo Ren wrote:
>
> > The pv_ops is belongs to x86 custom frame work, and it prevent other
> > architectures connect to the CNA spinlock.
>
> static_call() exists as a arch neutral variant of this.
Emm... we have used static_call() in the riscv queued_spin_lock_:
https://lore.kernel.org/all/20230802164701.192791-20-guoren@kernel.org/

But we met a compile problem:

  GEN     .vmlinux.objs
  MODPOST Module.symvers
ERROR: modpost: "__SCK__pv_queued_spin_unlock" [arch/riscv/kvm/kvm.ko]
undefined!
ERROR: modpost: "__SCK__pv_queued_spin_unlock"
[kernel/locking/locktorture.ko] undefined!
ERROR: modpost: "__SCK__pv_queued_spin_unlock" [mm/z3fold.ko] undefined!
ERROR: modpost: "__SCK__pv_queued_spin_unlock"
[fs/nfs_common/grace.ko] undefined!
ERROR: modpost: "__SCK__pv_queued_spin_unlock" [fs/quota/quota_v1.ko] undefined!
ERROR: modpost: "__SCK__pv_queued_spin_unlock" [fs/quota/quota_v2.ko] undefined!
ERROR: modpost: "__SCK__pv_queued_spin_unlock"
[fs/quota/quota_tree.ko] undefined!
ERROR: modpost: "__SCK__pv_queued_spin_unlock" [fs/fuse/virtiofs.ko] undefined!
ERROR: modpost: "__SCK__pv_queued_spin_unlock" [fs/dlm/dlm.ko] undefined!
ERROR: modpost: "__SCK__pv_queued_spin_unlock" [fs/fscache/fscache.ko]
undefined!
WARNING: modpost: suppressed 839 unresolved symbol warnings because
there were too many)
/home/guoren/source/kernel/linux/scripts/Makefile.modpost:144: recipe
for target 'Module.symvers' failed

Our solution is:
EXPORT_SYMBOL(__SCK__pv_queued_spin_unlock);

What do you think about it?

>
> > I'm working on riscv qspinlock on sg2042 64 cores 2/4 NUMA nodes
> > platforms. Here are the patches about riscv CNA qspinlock:
> > https://lore.kernel.org/linux-riscv/20230802164701.192791-19-guoren@kernel.org/
> >
> > What's the next plan for this patch series? I think the two-queue design
> > has satisfied most platforms with two NUMA nodes.
>
> What has been your reason for working on CNA? What lock has been so
> contended you need this?
I wrote the reason here:
https://lore.kernel.org/all/20230802164701.192791-1-guoren@kernel.org/

The target platform is: https://www.sophon.ai/

The two NUMA nodes platform has come out, so we want to measure the
benefit of CNA qspinlock.

Any feedbacks are welcome :)

-- 
Best Regards
 Guo Ren

  reply	other threads:[~2023-08-03 10:29 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-14 20:07 [PATCH v15 0/6] Add NUMA-awareness to qspinlock Alex Kogan
2021-05-14 20:07 ` [PATCH v15 1/6] locking/qspinlock: Rename mcs lock/unlock macros and make them more generic Alex Kogan
2021-05-14 20:07 ` [PATCH v15 2/6] locking/qspinlock: Refactor the qspinlock slow path Alex Kogan
2021-05-14 20:07 ` [PATCH v15 3/6] locking/qspinlock: Introduce CNA into the slow path of qspinlock Alex Kogan
2021-09-22 19:25   ` Davidlohr Bueso
2021-09-22 19:52     ` Waiman Long
2023-08-04  1:49     ` Guo Ren
2021-09-30 10:05   ` Barry Song
2023-08-02 23:14   ` Guo Ren
2023-08-03  8:50     ` Peter Zijlstra
2023-08-03 10:28       ` Guo Ren [this message]
2023-08-03 11:56         ` Peter Zijlstra
2023-08-04  1:33           ` Guo Ren
2023-08-04  1:38             ` Guo Ren
2023-08-04  8:25             ` Peter Zijlstra
2023-08-04 14:17               ` Guo Ren
2023-08-04 18:23                 ` Peter Zijlstra
2023-08-05  0:19                   ` Guo Ren
2021-05-14 20:07 ` [PATCH v15 4/6] locking/qspinlock: Introduce starvation avoidance into CNA Alex Kogan
2021-05-14 20:07 ` [PATCH v15 5/6] locking/qspinlock: Avoid moving certain threads between waiting queues in CNA Alex Kogan
2021-05-14 20:07 ` [PATCH v15 6/6] locking/qspinlock: Introduce the shuffle reduction optimization into CNA Alex Kogan
2021-09-30  9:44 ` [PATCH v15 0/6] Add NUMA-awareness to qspinlock Barry Song
2021-09-30 16:58   ` Waiman Long
2021-09-30 22:57     ` Barry Song
2021-09-30 23:51   ` Alex Kogan
2021-12-13 20:37 ` Alex Kogan
2021-12-15 15:13   ` Alex Kogan
2022-04-11 17:09 ` Alex Kogan

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