lkml.org 
[lkml]   [2013]   [Sep]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 0/3] KVM: Make kvm_lock non-raw
Il 22/09/2013 09:42, Gleb Natapov ha scritto:
> On Mon, Sep 16, 2013 at 04:06:10PM +0200, Paolo Bonzini wrote:
>> Paul Gortmaker reported a BUG on preempt-rt kernels, due to taking the
>> mmu_lock within the raw kvm_lock in mmu_shrink_scan. He provided a
>> patch that shrunk the kvm_lock critical section so that the mmu_lock
>> critical section does not nest with it, but in the end there is no reason
>> for the vm_list to be protected by a raw spinlock. Only manipulations
>> of kvm_usage_count and the consequent hardware_enable/disable operations
>> are not preemptable.
>>
>> This small series thus splits the kvm_lock in the "raw" part and the
>> "non-raw" part.
>>
>> Paul, could you please provide your Tested-by?
>>
> Reviewed-by: Gleb Natapov <gleb@redhat.com>
>
> But why should it go to stable?

It is a regression from before the kvm_lock was made raw. Secondarily,
it takes a much longer time before a patch hits -rt trees (can even be
as much as a year) and this patch does nothing on non-rt trees. So
without putting it into stable it would get no actual coverage.

Paolo


\
 
 \ /
  Last update: 2013-09-22 11:21    [W:0.119 / U:0.016 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site