From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Paul E. McKenney" Subject: Re: [PATCH RFC 21/26] powerpc: Remove spin_unlock_wait() arch-specific definitions Date: Wed, 5 Jul 2017 16:57:38 -0700 Message-ID: <20170705235738.GK2393@linux.vnet.ibm.com> References: <20170629235918.GA6445@linux.vnet.ibm.com> <1498780894-8253-21-git-send-email-paulmck@linux.vnet.ibm.com> <20170702035807.tnzmkynyevfobt5a@tardis> Reply-To: paulmck@linux.vnet.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, parri.andrea@gmail.com, dave@stgolabs.net, manfred@colorfullife.com, arnd@arndb.de, peterz@infradead.org, netdev@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, will.deacon@arm.com, oleg@redhat.com, mingo@redhat.com, netfilter-devel@vger.kernel.org, tj@kernel.org, stern@rowland.harvard.edu, akpm@linux-foundation.org, torvalds@linux-foundation.org, Paul Mackerras To: Boqun Feng Return-path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:36576 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751896AbdGEX5o (ORCPT ); Wed, 5 Jul 2017 19:57:44 -0400 Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v65Nsa3K132500 for ; Wed, 5 Jul 2017 19:57:43 -0400 Received: from e15.ny.us.ibm.com (e15.ny.us.ibm.com [129.33.205.205]) by mx0a-001b2d01.pphosted.com with ESMTP id 2bgvxcj1uq-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 05 Jul 2017 19:57:43 -0400 Received: from localhost by e15.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 5 Jul 2017 19:57:42 -0400 Content-Disposition: inline In-Reply-To: <20170702035807.tnzmkynyevfobt5a@tardis> Sender: netfilter-devel-owner@vger.kernel.org List-ID: On Sun, Jul 02, 2017 at 11:58:07AM +0800, Boqun Feng wrote: > On Thu, Jun 29, 2017 at 05:01:29PM -0700, Paul E. McKenney wrote: > > There is no agreed-upon definition of spin_unlock_wait()'s semantics, > > and it appears that all callers could do just as well with a lock/unlock > > pair. This commit therefore removes the underlying arch-specific > > arch_spin_unlock_wait(). > > > > Signed-off-by: Paul E. McKenney > > Cc: Benjamin Herrenschmidt > > Cc: Paul Mackerras > > Cc: Michael Ellerman > > Cc: > > Cc: Will Deacon > > Cc: Peter Zijlstra > > Cc: Alan Stern > > Cc: Andrea Parri > > Cc: Linus Torvalds > > Acked-by: Boqun Feng And finally applied in preparation for v2 of the patch series. Thank you!!! Thanx, Paul > Regards, > Boqun > > > --- > > arch/powerpc/include/asm/spinlock.h | 33 --------------------------------- > > 1 file changed, 33 deletions(-) > > > > diff --git a/arch/powerpc/include/asm/spinlock.h b/arch/powerpc/include/asm/spinlock.h > > index 8c1b913de6d7..d256e448ea49 100644 > > --- a/arch/powerpc/include/asm/spinlock.h > > +++ b/arch/powerpc/include/asm/spinlock.h > > @@ -170,39 +170,6 @@ static inline void arch_spin_unlock(arch_spinlock_t *lock) > > lock->slock = 0; > > } > > > > -static inline void arch_spin_unlock_wait(arch_spinlock_t *lock) > > -{ > > - arch_spinlock_t lock_val; > > - > > - smp_mb(); > > - > > - /* > > - * Atomically load and store back the lock value (unchanged). This > > - * ensures that our observation of the lock value is ordered with > > - * respect to other lock operations. > > - */ > > - __asm__ __volatile__( > > -"1: " PPC_LWARX(%0, 0, %2, 0) "\n" > > -" stwcx. %0, 0, %2\n" > > -" bne- 1b\n" > > - : "=&r" (lock_val), "+m" (*lock) > > - : "r" (lock) > > - : "cr0", "xer"); > > - > > - if (arch_spin_value_unlocked(lock_val)) > > - goto out; > > - > > - while (lock->slock) { > > - HMT_low(); > > - if (SHARED_PROCESSOR) > > - __spin_yield(lock); > > - } > > - HMT_medium(); > > - > > -out: > > - smp_mb(); > > -} > > - > > /* > > * Read-write spinlocks, allowing multiple readers > > * but only one writer. > > -- > > 2.5.2 > >