From: Guo Ren <guoren@kernel.org>
To: Waiman Long <longman@redhat.com>
Cc: "Palmer Dabbelt" <palmer@rivosinc.com>,
"Heiko Stübner" <heiko@sntech.de>,
"Christoph Hellwig" <hch@infradead.org>,
"Arnd Bergmann" <arnd@arndb.de>,
"Peter Zijlstra" <peterz@infradead.org>,
"Will Deacon" <will@kernel.org>,
"Boqun Feng" <boqun.feng@gmail.com>,
"Ingo Molnar" <mingo@redhat.com>,
"Philipp Tomsich" <philipp.tomsich@vrull.eu>,
"Christoph Muellner" <cmuellner@linux.com>,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
"David Laight" <David.Laight@aculab.com>,
linux-riscv <linux-riscv@lists.infradead.org>,
linux-csky@vger.kernel.org, "Guo Ren" <guoren@linux.alibaba.com>
Subject: Re: [PATCH V8 10/10] csky: Add qspinlock support
Date: Mon, 25 Jul 2022 10:30:33 +0800 [thread overview]
Message-ID: <CAJF2gTSf4EX_QpbfgKdYtHK-gShsqh5UcLi5xiMcVDRWx1VxHg@mail.gmail.com> (raw)
In-Reply-To: <0ea27d18-6d45-9673-38b7-78d59325f9d5@redhat.com>
On Mon, Jul 25, 2022 at 10:08 AM Waiman Long <longman@redhat.com> wrote:
>
> On 7/24/22 08:25, guoren@kernel.org wrote:
> > From: Guo Ren <guoren@linux.alibaba.com>
> >
> > Enable qspinlock by the requirements mentioned in a8ad07e5240c9
> > ("asm-generic: qspinlock: Indicate the use of mixed-size atomics").
> >
> > C-SKY only has "ldex/stex" for all atomic operations. So csky give a
> > strong forward guarantee for "ldex/stex." That means when ldex grabbed
> > the cache line into $L1, it would block other cores from snooping the
> > address with several cycles.
> >
> > Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> > Signed-off-by: Guo Ren <guoren@kernel.org>
> > ---
> > arch/csky/Kconfig | 16 ++++++++++++++++
> > arch/csky/include/asm/Kbuild | 2 ++
> > arch/csky/include/asm/cmpxchg.h | 20 ++++++++++++++++++++
> > 3 files changed, 38 insertions(+)
> >
> > diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig
> > index dfdb436b6078..09f7d1f06bca 100644
> > --- a/arch/csky/Kconfig
> > +++ b/arch/csky/Kconfig
> > @@ -354,6 +354,22 @@ config HAVE_EFFICIENT_UNALIGNED_STRING_OPS
> > Say Y here to enable EFFICIENT_UNALIGNED_STRING_OPS. Some CPU models could
> > deal with unaligned access by hardware.
> >
> > +choice
> > + prompt "C-SKY spinlock type"
> > + default CSKY_TICKET_SPINLOCKS
> > +
> > +config CSKY_TICKET_SPINLOCKS
> > + bool "Using ticket spinlock"
> > +
> > +config CSKY_QUEUED_SPINLOCKS
> > + bool "Using queued spinlock"
> > + depends on SMP
> > + select ARCH_USE_QUEUED_SPINLOCKS
> > + help
> > + Make sure your micro arch LL/SC has a strong forward progress guarantee.
> > + Otherwise, stay at ticket-lock/combo-lock.
>
> "combo-lock"? It is a cut-and-paste error. Right?
Yes, it's a typo. No combo-lock for csky.
>
> Cheers,
> Longman
>
--
Best Regards
Guo Ren
prev parent reply other threads:[~2022-07-25 2:30 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-24 12:25 [PATCH V8 00/10] arch: Add qspinlock support with combo style guoren
2022-07-24 12:25 ` [PATCH V8 01/10] asm-generic: ticket-lock: Remove unnecessary atomic_read guoren
2022-07-24 12:25 ` [PATCH V8 02/10] asm-generic: ticket-lock: Use the same struct definitions with qspinlock guoren
2022-07-27 19:20 ` kernel test robot
2022-07-24 12:25 ` [PATCH V8 03/10] asm-generic: ticket-lock: Move into ticket_spinlock.h guoren
2022-07-24 12:25 ` [PATCH V8 04/10] asm-generic: spinlock: Add queued spinlock support in common header guoren
2022-07-24 12:25 ` [PATCH V8 05/10] riscv: Enable ARCH_INLINE_READ*/WRITE*/SPIN* guoren
2022-07-24 12:25 ` [PATCH V8 06/10] riscv: atomic: Clean up unnecessary acquire and release definitions guoren
2022-07-24 12:25 ` [PATCH V8 07/10] riscv: Add qspinlock support guoren
2022-07-28 0:04 ` kernel test robot
2022-07-28 3:35 ` Guo Ren
2022-07-28 8:14 ` Arnd Bergmann
2022-07-28 8:34 ` Guo Ren
2022-07-24 12:25 ` [PATCH V8 08/10] riscv: Add combo spinlock support guoren
2022-07-24 12:25 ` [PATCH V8 09/10] csky: Enable ARCH_INLINE_READ*/WRITE*/SPIN* guoren
2022-07-24 12:25 ` [PATCH V8 10/10] csky: Add qspinlock support guoren
2022-07-25 2:08 ` Waiman Long
2022-07-25 2:30 ` Guo Ren [this message]
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