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SubjectRe: [PATCH] delaying interrupts in mips [ 2.6.32]
On 08/11/2014 03:33 PM, Sadasivan Shaiju wrote:
> Hi David,
>
> Sorry , I didn't check that . I am late in submitting it .

OK. Next time try to apply your patch and test it before submitting.

David Daney

>
> Regards,
> Shaiju.
>
> -----Original Message-----
> From: David Daney [mailto:ddaney@caviumnetworks.com]
> Sent: Monday, August 11, 2014 3:28 PM
> To: Sadasivan Shaiju
> Cc: linux-kernel@vger.kernel.org; ralf@linux-mips.org;
> david.daney@cavium.com; shaiju_sada@yahoo.com
> Subject: Re: [PATCH] delaying interrupts in mips [ 2.6.32]
>
> On 08/11/2014 03:13 PM, Sadasivan Shaiju wrote:
>> Hi ,
>>
>> I work for Montavista (Cavium Inc) as a Technical Lead . I want
>> to push some of the kernel patches to rt community (2.6.32 kernel
>> 2.6.33 rt patch) , so that It will go to the main line These
>> patches are reviewed and approved by our system Architect. I
>> request you to include in the main line .
>
> It is already in the "main line":
>
> commit 1bcfecc028686ea32e49b0f4f6e8a665917cb49a
> Author: Yong Zhang <yong.zhang@windriver.com>
> Date: Thu Jul 19 09:13:53 2012 +0200
>
> MIPS: Octeon: delay enable irq to ->smp_finish()
>
> To prepare for smoothing set_cpu_[active|online]() mess up
>
> Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
> Cc: Sergei Shtylyov <sshtylyov@mvista.com>
> Cc: David Daney <david.daney@cavium.com>
> Acked-by: David Daney <david.daney@cavium.com>
> Patchwork: https://patchwork.linux-mips.org/patch/3845/
> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
>
> Why are you sending it again?
>
> David Daney
>
>
>
> These issues were reported by our
>> customer CISCO .
>>
>> Problem Description:
>> When CONFIG_DEBUG_PREEMPT is enabled the following stack trace occurs.
>>
>> [ 170.814470] BUG: using smp_processor_id() in preemptible [00000000]
>> code: sirq-timer/4/62
>> [ 170.814482] caller is hrtimer_run_pending+0x10/0x20 [ 170.814488]
>> Call Trace:
>> [ 170.814496] [<ffffffff8010d844>] dump_stack+0x8/0x34 [ 170.814507]
>> [<ffffffff803c2598>] debug_smp_processor_id+0xe0/0xf0 [ 170.814517]
>> [<ffffffff80254158>] hrtimer_run_pending+0x10/0x20 [ 170.814528]
>> [<ffffffff80242400>] run_timer_softirq+0x60/0x348 [ 170.814539]
>> [<ffffffff8023ae80>] run_ksoftirqd+0x1c8/0x348 [ 170.814550]
>> [<ffffffff802503f8>] kthread+0x88/0x90 [ 170.814561]
>> [<ffffffff80206c80>] kernel_thread_helper+0x10/0x18
>>
>> Root Cause:
>> Interrupt was occurring before the processor was completely up, and
>> the softirq threads were unable to schedule on the processor and then
>> ran on the wrong CPU.
>>
>> How Solved:
>> Enabling of interrupt has been delayed till smp_finish so that
>> kthread_bind can safely bind threads to any possible CPU.
>>
>> I request you to merge the above patch to the main line . If any
>> questions please contact me atsshaiju@mvista.com
>> (shaiju_sada@yahoo.com)
>>
>> Regards,
>> Shaiju.
>>
>>
>> 0001-Interrupt-delaying-enabling-of-interrupt.patch
>>
>>
>> From 58512475cba93003c23f2b380b573e64eebcabd5 Mon Sep 17 00:00:00
>> 2001
>> From: Sadasivan Shaiju<sshaiju@mvista.com>
>> Date: Mon, 20 Feb 2012 13:25:50 -0800
>> Subject: [PATCH] Interrupt : delaying enabling of interrupt
>>
>> Source: MontaVista Software, LLC
>> MR: 47157
>> Type: Defect Fix
>> Disposition: Local
>> ChangeID: 48c837329556b161f3111e6fded1c9857fa3a149
>> Description:
>>
>> This patch is to delay the enabling of interrupt till smp_finish . So
>> that kthread_bind can safely bind threads to any possible cpu. Without
>> this change interrupt should occur beofre the processor was
>> completely up, and the softirq threads were unable to schedule on the
>> processor and then ran on the wrong CPU.
>>
>> Signed-off-by: Sadasivan Shaiju<sshaiju@mvista.com>
>> ---
>> arch/mips/cavium-octeon/smp.c | 3 ++-
>> 1 files changed, 2 insertions(+), 1 deletions(-)
>>
>> diff --git a/arch/mips/cavium-octeon/smp.c
>> b/arch/mips/cavium-octeon/smp.c index ff21542..c7de7ac 100644
>> --- a/arch/mips/cavium-octeon/smp.c
>> +++ b/arch/mips/cavium-octeon/smp.c
>> @@ -308,7 +308,6 @@ static void octeon_init_secondary(void)
>> octeon_init_cvmcount();
>>
>> octeon_irq_setup_secondary();
>> - raw_local_irq_enable();
>> }
>>
>> /**
>> @@ -365,6 +364,8 @@ static void octeon_smp_finish(void)
>>
>> /* to generate the first CPU timer interrupt */
>> write_c0_compare(read_c0_count() + mips_hpt_frequency / HZ);
>> + /* enable local interrupts */
>> + raw_local_irq_enable();
>> }
>>
>> /**
>> -- 1.7.0.1



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