Messages in this thread | | | From | "Liu, Chuansheng" <> | Subject | RE: [PATCH] lib/spinlock_debug: Tweak the loop time to fit different _delay() | Date | Wed, 30 Apr 2014 09:30:55 +0000 |
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Hello Peter,
> -----Original Message----- > From: Peter Zijlstra [mailto:peterz@infradead.org] > Sent: Wednesday, April 30, 2014 4:55 PM > To: Wang, Xiaoming > Cc: mingo@redhat.com; linux-kernel@vger.kernel.org; Liu, Chuansheng > Subject: Re: [PATCH] lib/spinlock_debug: Tweak the loop time to fit different > _delay() > > On Wed, Apr 30, 2014 at 06:40:38PM -0400, Wang, Xiaoming wrote: > > loops_per_jiffy*Hz is not always 1 second exactly > > it depends on the realization of _delay() . > > delay_tsc is used as _delay() in arch/x86/lib/delay.c > > This just states delay() is broken. The primary response should be to > try and fix that, no?
delay(1s_count) is accurate, but delay(1) is not accurate indeed, since executing some instruction, then the 1 cycle delay maybe be used already.
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