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From: Anthony Liguori <anthony-rdkfGonbjUSkNkDKm+mE6A@public.gmane.org>
To: Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
Cc: kvm-devel <kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org>
Subject: Re: [PATCH] Lazy FPU for SVM
Date: Tue, 24 Apr 2007 08:59:46 -0500	[thread overview]
Message-ID: <462E0D52.5000707@codemonkey.ws> (raw)
In-Reply-To: <462DDE52.5040303-atKUWr5tajBWk0Htik3J/w@public.gmane.org>

Avi Kivity wrote:
> Anthony Liguori wrote:
>
> [updated patch]
>
> Applied.
>
>   
>> Hard to say exactly because of the noise.  I did two runs of 4
>> test/vmexit:
>>
>> Before 4091, 4194, 4559, 4439
>> After: 3979, 4324, 3918, 3910
>>
>> So there's definitely a speedup, but probably only 100-200 cycles.
>>
>>     
>
> Running on an idle, headless server with the vcpu pinned reduces
> variability to a few cycles in the after case.  Strangely, the
> variability is high in the before case.  I get a similar disappointing
> result of 100-200 cycles.
>   

I previously measured how long fx_save/fx_restore took and it was right 
around 150 cycles on AMD.

Regards,

Anthony Liguori


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  parent reply	other threads:[~2007-04-24 13:59 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-04-23  2:56 [PATCH] Lazy FPU for SVM Anthony Liguori
     [not found] ` <462C2048.4040700-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
2007-04-23  6:50   ` Avi Kivity
     [not found]     ` <462C574E.2030304-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
2007-04-23 14:32       ` Anthony Liguori
     [not found]         ` <462CC380.5020405-rdkfGonbjUSkNkDKm+mE6A@public.gmane.org>
2007-04-24 10:39           ` Avi Kivity
     [not found]             ` <462DDE52.5040303-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
2007-04-24 13:59               ` Anthony Liguori [this message]
     [not found]                 ` <462E0D52.5000707-rdkfGonbjUSkNkDKm+mE6A@public.gmane.org>
2007-04-24 14:32                   ` Avi Kivity
2007-04-25  8:03           ` [PATCH] Remove redundant MSR save/restore Dong, Eddie
     [not found]             ` <10EA09EFD8728347A513008B6B0DA77A01599D74-wq7ZOvIWXbNpB2pF5aRoyrfspsVTdybXVpNB7YpNyf8@public.gmane.org>
2007-04-25  8:17               ` Avi Kivity
     [not found]                 ` <462F0E90.8010307-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
2007-04-25  8:53                   ` Dong, Eddie
     [not found]                     ` <10EA09EFD8728347A513008B6B0DA77A01599E01-wq7ZOvIWXbNpB2pF5aRoyrfspsVTdybXVpNB7YpNyf8@public.gmane.org>
2007-04-25  9:28                       ` Avi Kivity
2007-04-25  7:30   ` [PATCH] Remove heavy is_empty_shadow_page call Dong, Eddie
     [not found]     ` <10EA09EFD8728347A513008B6B0DA77A01599D2B-wq7ZOvIWXbNpB2pF5aRoyrfspsVTdybXVpNB7YpNyf8@public.gmane.org>
2007-04-25  8:03       ` Avi Kivity
     [not found]         ` <462F0B40.9060109-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
2007-04-25  8:09           ` Dong, Eddie
     [not found]             ` <10EA09EFD8728347A513008B6B0DA77A01599D87-wq7ZOvIWXbNpB2pF5aRoyrfspsVTdybXVpNB7YpNyf8@public.gmane.org>
2007-04-25  8:20               ` Avi Kivity
2007-04-25  8:40       ` Michael Riepe
     [not found]         ` <462F13E0.80104-0QoEqw4nQxo@public.gmane.org>
2007-04-25  8:45           ` Dong, Eddie
2007-04-25  8:49           ` Avi Kivity

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