From mboxrd@z Thu Jan  1 00:00:00 1970
From: Avi Kivity <avi@redhat.com>
Subject: Re: [PATCH RFC v2 5/6] KVM: moving dirty bitmaps to user space
Date: Fri, 23 Apr 2010 13:28:53 +0300
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References: <20100420195349.dab60b1d.yoshikawa.takuya@oss.ntt.co.jp> <20100420200225.efca602f.yoshikawa.takuya@oss.ntt.co.jp> <4BCEE0E4.6060707@redhat.com> <4BD011E8.6020502@oss.ntt.co.jp>
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	kvm-ppc@vger.kernel.org, fernando@oss.ntt.co.jp
To: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
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On 04/22/2010 12:07 PM, Takuya Yoshikawa wrote:
>
>>
>>> + slots->memslots[i].dirty_bitmap = NULL;
>>> + slots->memslots[i].dirty_bitmap_old = NULL;
>>> kvm_free_physmem_slot(&slots->memslots[i], NULL);
>>> + }
>>>
>>>
>>> +/*
>>> + * Please use generic *_user bitops once they become available.
>>> + * Be careful setting the bit won't be done atomically.
>>> + */
>>
>> Please introduce the user bitops as part of this patchset.
>>
>
> OK, I will do in the next version. In this RFC, I would be happy if I can
> know the overall design is right or not.
>

Everything looks reasonable to me.

Do you have performance numbers?  I'm interested in both measurements of 
KVM_SWITCH_DIRTY_LOG under various conditions and macro benchmarks (for 
example, total guest throughput improvement under Kemari).

-- 
Do not meddle in the internals of kernels, for they are subtle and quick to panic.