lkml.org 
[lkml]   [2013]   [Feb]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH -v4 5/5] x86,smp: limit spinlock delay on virtual machines
On 01/26/2013 07:47 AM, Borislav Petkov wrote:
> On Sat, Jan 26, 2013 at 01:00:43PM +0100, Ingo Molnar wrote:
>>> +void __init init_spinlock_delay(void)
>>> +{
>>> + if (x86_hyper)
>>> + max_spinlock_delay = MAX_SPINLOCK_DELAY_GUEST;
>>
>> I realize that you took existing code and extended it, but that
>> chunk of code looks pretty disgusting visually now - at minimum
>> it should be vertically aligned as most other kernel code does.
>>
>> The comment should also tell that the unit of these values is
>> 'spinlock-op loops' or so.

Will do.

> Also, with currently making PARAVIRT_GUEST optional, x86_hyper is maybe
> a bad choice of a variable to test.
>
> Maybe instead to this:
>
> if (IS_ENABLED(CONFIG_PARAVIRT_GUEST))
> ...

We need to know whether we are actually running on top of a
hypervisor, not whether we have the code compiled in to do
so.

After all, the majority of distribution kernels will have
CONFIG_PARAVIRT_GUEST set, but the majority of those kernels
will be running bare metal...

--
All rights reversed


\
 
 \ /
  Last update: 2013-02-04 15:26    [W:1.080 / U:0.084 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site