From: Frank Rowand <frank.rowand@am.sony.com>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Chris Mason <chris.mason@oracle.com>,
"Rowand, Frank" <Frank_Rowand@sonyusa.com>,
Ingo Molnar <mingo@elte.hu>, Thomas Gleixner <tglx@linutronix.de>,
Mike Galbraith <efault@gmx.de>, Oleg Nesterov <oleg@redhat.com>,
Paul Turner <pjt@google.com>, Jens Axboe <axboe@kernel.dk>,
Yong Zhang <yong.zhang0@gmail.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Russell King <rmk+kernel@arm.linux.org.uk>,
Martin Schwidefsky <schwidefsky@de.ibm.com>,
Chris Metcalf <cmetcalf@tilera.com>,
Jesper Nilsson <jesper.nilsson@axis.com>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Ralf Baechle <ralf@linux-mips.org>
Subject: Re: [PATCH 01/22] sched: Provide scheduler_ipi() callback in response to smp_send_reschedule()
Date: Thu, 10 Mar 2011 17:36:08 -0800 [thread overview]
Message-ID: <4D797C88.7080607@am.sony.com> (raw)
In-Reply-To: <20110302174120.313761743@chello.nl>
On 03/02/11 09:38, Peter Zijlstra wrote:
> For future rework of try_to_wake_up() we'd like to push part of that
> onto the CPU the task is actually going to run on, in order to do so we
> need a generic callback from the existing scheduler IPI.
>
> This patch introduces such a generic callback: scheduler_ipi() and
> implements it as a NOP.
>
> BenH notes: PowerPC might use this IPI on offline CPUs under rare
> conditions!!
>
> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
> Acked-by: Chris Metcalf <cmetcalf@tilera.com>
> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
> LKML-Reference: <new-submission>
> ---
> arch/alpha/kernel/smp.c | 3 +--
> arch/arm/kernel/smp.c | 5 +----
> arch/blackfin/mach-common/smp.c | 3 +++
> arch/cris/arch-v32/kernel/smp.c | 13 ++++++++-----
> arch/ia64/kernel/irq_ia64.c | 2 ++
> arch/ia64/xen/irq_xen.c | 10 +++++++++-
> arch/m32r/kernel/smp.c | 4 +---
> arch/mips/cavium-octeon/smp.c | 2 ++
> arch/mips/kernel/smtc.c | 2 +-
> arch/mips/mti-malta/malta-int.c | 2 ++
> arch/mips/pmc-sierra/yosemite/smp.c | 4 ++++
> arch/mips/sgi-ip27/ip27-irq.c | 2 ++
> arch/mips/sibyte/bcm1480/smp.c | 7 +++----
> arch/mips/sibyte/sb1250/smp.c | 7 +++----
> arch/mn10300/kernel/smp.c | 5 +----
> arch/parisc/kernel/smp.c | 5 +----
> arch/powerpc/kernel/smp.c | 3 ++-
> arch/s390/kernel/smp.c | 6 +++---
> arch/sh/kernel/smp.c | 2 ++
> arch/sparc/kernel/smp_32.c | 2 +-
> arch/sparc/kernel/smp_64.c | 1 +
> arch/tile/kernel/smp.c | 6 +-----
> arch/um/kernel/smp.c | 2 +-
> arch/x86/kernel/smp.c | 5 ++---
> arch/x86/xen/smp.c | 5 ++---
> include/linux/sched.h | 1 +
> 26 files changed, 60 insertions(+), 49 deletions(-)
>
< snip >
In this patch the tabs turned into spaces. (None of the other
patches have this problem.)
> Index: linux-2.6/arch/sparc/kernel/smp_32.c
> ===================================================================
> --- linux-2.6.orig/arch/sparc/kernel/smp_32.c
> +++ linux-2.6/arch/sparc/kernel/smp_32.c
> @@ -125,7 +125,7 @@ struct linux_prom_registers smp_penguin_
>
> void smp_send_reschedule(int cpu)
> {
> - /* See sparc64 */
> + scheduler_ipi();
> }
If I understand correctly, this is calling scheduler_ipi() on the
cpu that should be sending an IPI, not on the cpu receiving the IPI.
If so, smp_send_reschedule() needs to send an IPI, and the scheduler_ipi()
put in the place where the IPI is processed.
-Frank
next prev parent reply other threads:[~2011-03-11 1:36 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-02 17:38 [PATCH 00/22] sched: Reduce runqueue lock contention -v5 Peter Zijlstra
2011-03-02 17:38 ` [PATCH 01/22] sched: Provide scheduler_ipi() callback in response to smp_send_reschedule() Peter Zijlstra
2011-03-11 1:36 ` Frank Rowand [this message]
2011-03-16 8:30 ` Peter Zijlstra
2011-03-11 15:07 ` [01/22] " Milton Miller
2011-03-11 15:27 ` Peter Zijlstra
2011-03-15 3:59 ` Milton Miller
2011-03-15 9:13 ` Peter Zijlstra
2011-03-02 17:38 ` [PATCH 02/22] sched: Always provide p->on_cpu Peter Zijlstra
2011-03-02 17:38 ` [PATCH 03/22] mutex: Use p->on_cpu for the adaptive spin Peter Zijlstra
2011-03-02 17:38 ` [PATCH 04/22] sched: Change the ttwu success details Peter Zijlstra
2011-03-02 17:38 ` [PATCH 05/22] sched: Clean up ttwu stats Peter Zijlstra
2011-03-02 17:38 ` [PATCH 06/22] sched: Provide p->on_rq Peter Zijlstra
2011-03-02 17:38 ` [PATCH 07/22] sched: Serialize p->cpus_allowed and ttwu() using p->pi_lock Peter Zijlstra
2011-03-02 17:38 ` [PATCH 08/22] sched: Drop the rq argument to sched_class::select_task_rq() Peter Zijlstra
2011-03-02 17:38 ` [PATCH 09/22] sched: Remove rq argument to sched_class::task_waking() Peter Zijlstra
2011-03-02 17:38 ` [PATCH 10/22] sched: Deal with non-atomic min_vruntime reads on 32bits Peter Zijlstra
2011-03-02 17:38 ` [PATCH 11/22] sched: Delay task_contributes_to_load() Peter Zijlstra
2011-03-02 17:38 ` [PATCH 12/22] sched: Also serialize ttwu_local() with p->pi_lock Peter Zijlstra
2011-03-02 17:38 ` [PATCH 13/22] sched: Add p->pi_lock to task_rq_lock() Peter Zijlstra
2011-03-02 17:38 ` [PATCH 14/22] sched: Drop rq->lock from first part of wake_up_new_task() Peter Zijlstra
2011-03-02 17:38 ` [PATCH 15/22] sched: Drop rq->lock from sched_exec() Peter Zijlstra
2011-03-02 17:38 ` [PATCH 16/22] sched: Remove rq->lock from the first half of ttwu() Peter Zijlstra
2011-03-02 17:38 ` [PATCH 17/22] sched: Remove rq argument from ttwu_stat() Peter Zijlstra
2011-03-02 17:38 ` [PATCH 18/22] sched: Rename ttwu_post_activation Peter Zijlstra
2011-03-02 17:38 ` [PATCH 19/22] sched: Restructure ttwu some more Peter Zijlstra
2011-03-02 17:38 ` [PATCH 20/22] sched: Move the second half of ttwu() to the remote cpu Peter Zijlstra
2011-03-11 1:44 ` Frank Rowand
2011-03-16 8:32 ` Peter Zijlstra
2011-03-02 17:38 ` [PATCH 21/22] sched: Remove need_migrate_task() Peter Zijlstra
2011-03-02 17:38 ` [PATCH 22/22] sched: Remove TASK_WAKING Peter Zijlstra
2011-03-11 1:49 ` Frank Rowand
2011-03-16 9:53 ` Peter Zijlstra
2011-03-11 1:51 ` [PATCH 00/22] sched: Reduce runqueue lock contention -v5 Frank Rowand
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