From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
To: linux-arch@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org, Nicholas Piggin <npiggin@gmail.com>
Subject: Re: [PATCH][RFC] Implement arch primitives for busywait loops
Date: Mon, 19 Sep 2016 10:35:37 +0530 [thread overview]
Message-ID: <87vaxsxyvy.fsf@linux.vnet.ibm.com> (raw)
In-Reply-To: <20160916085736.7857-1-npiggin@gmail.com>
> diff --git a/include/linux/bit_spinlock.h b/include/linux/bit_spinlock.h
> index 3b5bafc..695743c 100644
> --- a/include/linux/bit_spinlock.h
> +++ b/include/linux/bit_spinlock.h
> @@ -25,9 +25,8 @@ static inline void bit_spin_lock(int bitnum, unsigned long *addr)
> #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
> while (unlikely(test_and_set_bit_lock(bitnum, addr))) {
> preempt_enable();
> - do {
> - cpu_relax();
> - } while (test_bit(bitnum, addr));
> + spin_do {
> + } spin_while (test_bit(bitnum, addr));
> preempt_disable();
> }
> #endif
That usage is strange, with nothing in the do{ }while loop. May be add a
macro for usages like this ?
-aneesh
WARNING: multiple messages have this Message-ID (diff)
From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
To: Nicholas Piggin <npiggin@gmail.com>, linux-arch@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH][RFC] Implement arch primitives for busywait loops
Date: Mon, 19 Sep 2016 10:35:37 +0530 [thread overview]
Message-ID: <87vaxsxyvy.fsf@linux.vnet.ibm.com> (raw)
Message-ID: <20160919050537.m-PBi-Hbd1jdgLKqaf4T_qV56oLw1wUiQoaKmwuUdQA@z> (raw)
In-Reply-To: <20160916085736.7857-1-npiggin@gmail.com>
> diff --git a/include/linux/bit_spinlock.h b/include/linux/bit_spinlock.h
> index 3b5bafc..695743c 100644
> --- a/include/linux/bit_spinlock.h
> +++ b/include/linux/bit_spinlock.h
> @@ -25,9 +25,8 @@ static inline void bit_spin_lock(int bitnum, unsigned long *addr)
> #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
> while (unlikely(test_and_set_bit_lock(bitnum, addr))) {
> preempt_enable();
> - do {
> - cpu_relax();
> - } while (test_bit(bitnum, addr));
> + spin_do {
> + } spin_while (test_bit(bitnum, addr));
> preempt_disable();
> }
> #endif
That usage is strange, with nothing in the do{ }while loop. May be add a
macro for usages like this ?
-aneesh
next prev parent reply other threads:[~2016-09-19 5:05 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-16 8:57 [PATCH][RFC] Implement arch primitives for busywait loops Nicholas Piggin
2016-09-16 11:30 ` David Laight
2016-09-16 11:52 ` Nicholas Piggin
2016-09-16 11:57 ` David Laight
2016-09-16 11:57 ` David Laight
2016-09-16 12:06 ` Nicholas Piggin
2016-09-16 12:59 ` Nicholas Piggin
2016-09-19 5:05 ` Aneesh Kumar K.V [this message]
2016-09-19 5:05 ` Aneesh Kumar K.V
2016-09-19 7:45 ` Balbir Singh
2016-09-19 8:48 ` Nicholas Piggin
2016-09-19 8:48 ` Nicholas Piggin
2016-09-20 11:19 ` Christian Borntraeger
2016-09-20 12:27 ` Nicholas Piggin
2016-09-20 12:35 ` Christian Borntraeger
2016-09-20 12:46 ` Nicholas Piggin
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