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From: Peter Zijlstra <peterz@infradead.org>
To: "Wang, Xiaoming" <xiaoming.wang@intel.com>
Cc: "mingo@redhat.com" <mingo@redhat.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"Liu, Chuansheng" <chuansheng.liu@intel.com>
Subject: Re: [PATCH] lib/spinlock_debug: avoid one thread can not obtain the spinlock for a long time.
Date: Wed, 30 Apr 2014 09:43:07 +0200	[thread overview]
Message-ID: <20140430074307.GX11096@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <FA47D36D6EC9FE4CB463299737C09B9901C14B96@shsmsx102.ccr.corp.intel.com>

On Wed, Apr 30, 2014 at 06:17:48AM +0000, Wang, Xiaoming wrote:
> Dear Peter
> 	If we wait the end of loop as loops_per_jiffy. 
> It may last more than 130s and local IRQ disabled at interval 
> which may cause Hard LOCKUP. We break out in 1 second and
> dump the stack for debug.

Yeah, so? That makes shoddy engineering alright then?

So either fix the loops_per_jiffy thing, it is supposed to wait for 1
second after all, or explain why its broken and entirely replace it.

What you do not do is make a loop with 2 differently broken timeouts and
hope one works.

      reply	other threads:[~2014-04-30  7:43 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-04-30 17:04 Wang, Xiaoming
2014-04-30  6:06 ` Peter Zijlstra
2014-04-30  6:17   ` Wang, Xiaoming
2014-04-30  7:43     ` Peter Zijlstra [this message]

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