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
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, 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
next prev parent reply other threads:[~2016-09-19 5:05 UTC|newest]
Thread overview: 17+ 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 11:30 ` 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 5:05 ` Aneesh Kumar K.V
2016-09-19 7:45 ` Balbir Singh
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=87vaxsxyvy.fsf@linux.vnet.ibm.com \
--to=aneesh.kumar@linux.vnet.ibm.com \
--cc=linux-arch@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=npiggin@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.