Joanna Rutkowska
2012-May-30 10:14 UTC
Noticeably poor Intel GPU performance on 3.3 and 3.4 dom0 kernels
Hello, I''ve recently been some newer Dom0 kernels (3.3.5, 3.4) under Xen 4.1.2, and have noticed that those kernel noticeably downgrade performance of (at least) Intel GPUs. This is easily noticeable even on such trivial tasks as scrolling a webpage in Firefox or Chrome. This slow GPU performance on 3.3 and 3.4 kernels is in stark contrast with what I see on 3.2.7 Dom0 kernel, where graphics works just great... In order to make sure that this is not caused by power management set too strictly, I played with xenpm and made sure to set the following: 1) xenpm set-scaling-governor performance 2) xenpm set-max-cstate 0 I have verified then that my processor: 1) keeps staying in P0 state (so, max frequency), and 2) keeps staying in C0 state. Those setting didn''t change anything regarding the poor graphics performance, though. Any ideas what else I could test to find out the cause of this? Thanks, joanna. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
Jan Beulich
2012-May-30 10:37 UTC
Re: Noticeably poor Intel GPU performance on 3.3 and 3.4 dom0 kernels
>>> On 30.05.12 at 12:14, Joanna Rutkowska <joanna@invisiblethingslab.com> wrote: > I''ve recently been some newer Dom0 kernels (3.3.5, 3.4) under Xen 4.1.2, > and have noticed that those kernel noticeably downgrade performance of > (at least) Intel GPUs. This is easily noticeable even on such trivial > tasks as scrolling a webpage in Firefox or Chrome. This slow GPU > performance on 3.3 and 3.4 kernels is in stark contrast with what I see > on 3.2.7 Dom0 kernel, where graphics works just great... > > In order to make sure that this is not caused by power management set > too strictly, I played with xenpm and made sure to set the following: > 1) xenpm set-scaling-governor performance > 2) xenpm set-max-cstate 0 > > I have verified then that my processor: 1) keeps staying in P0 state > (so, max frequency), and 2) keeps staying in C0 state. > > Those setting didn''t change anything regarding the poor graphics > performance, though. > > Any ideas what else I could test to find out the cause of this?To check whether the DRM drivers'' supposedly more extensive use of the DMA API is the reason, could you check whether the performance is as bad with "mem=4G" on the Xen command line? Jan
Konrad Rzeszutek Wilk
2012-May-30 14:28 UTC
Re: Noticeably poor Intel GPU performance on 3.3 and 3.4 dom0 kernels
On Wed, May 30, 2012 at 12:14:07PM +0200, Joanna Rutkowska wrote:> Hello, > > I''ve recently been some newer Dom0 kernels (3.3.5, 3.4) under Xen 4.1.2, > and have noticed that those kernel noticeably downgrade performance of > (at least) Intel GPUs. This is easily noticeable even on such trivial > tasks as scrolling a webpage in Firefox or Chrome. This slow GPU > performance on 3.3 and 3.4 kernels is in stark contrast with what I see > on 3.2.7 Dom0 kernel, where graphics works just great... > > In order to make sure that this is not caused by power management set > too strictly, I played with xenpm and made sure to set the following:And are you building with CONFIG_INTEL_IOMMU=y?> 1) xenpm set-scaling-governor performance > 2) xenpm set-max-cstate 0 > > I have verified then that my processor: 1) keeps staying in P0 state > (so, max frequency), and 2) keeps staying in C0 state. > > Those setting didn''t change anything regarding the poor graphics > performance, though. > > Any ideas what else I could test to find out the cause of this? > > Thanks, > joanna. >> _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > http://lists.xen.org/xen-devel
Marek Marczykowski
2012-May-30 14:57 UTC
Re: Noticeably poor Intel GPU performance on 3.3 and 3.4 dom0 kernels
On 30.05.2012 16:28, Konrad Rzeszutek Wilk wrote:> On Wed, May 30, 2012 at 12:14:07PM +0200, Joanna Rutkowska wrote: >> Hello, >> >> I''ve recently been some newer Dom0 kernels (3.3.5, 3.4) under Xen 4.1.2, >> and have noticed that those kernel noticeably downgrade performance of >> (at least) Intel GPUs. This is easily noticeable even on such trivial >> tasks as scrolling a webpage in Firefox or Chrome. This slow GPU >> performance on 3.3 and 3.4 kernels is in stark contrast with what I see >> on 3.2.7 Dom0 kernel, where graphics works just great... >> >> In order to make sure that this is not caused by power management set >> too strictly, I played with xenpm and made sure to set the following: > > And are you building with CONFIG_INTEL_IOMMU=y?Yes: CONFIG_GART_IOMMU=y # CONFIG_CALGARY_IOMMU is not set CONFIG_SWIOTLB=y CONFIG_IOMMU_HELPER=y (...) CONFIG_IOMMU_API=y CONFIG_IOMMU_SUPPORT=y CONFIG_AMD_IOMMU=y # CONFIG_AMD_IOMMU_STATS is not set CONFIG_AMD_IOMMU_V2=m CONFIG_DMAR_TABLE=y CONFIG_INTEL_IOMMU=y CONFIG_INTEL_IOMMU_DEFAULT_ON=y CONFIG_INTEL_IOMMU_FLOPPY_WA=y CONFIG_IRQ_REMAP=y> >> 1) xenpm set-scaling-governor performance >> 2) xenpm set-max-cstate 0 >> >> I have verified then that my processor: 1) keeps staying in P0 state >> (so, max frequency), and 2) keeps staying in C0 state. >> >> Those setting didn''t change anything regarding the poor graphics >> performance, though. >> >> Any ideas what else I could test to find out the cause of this? >> >> Thanks, >> joanna. >> > > > >> _______________________________________________ >> Xen-devel mailing list >> Xen-devel@lists.xen.org >> http://lists.xen.org/xen-devel >-- Best Regards / Pozdrawiam, Marek Marczykowski Invisible Things Lab _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
Konrad Rzeszutek Wilk
2012-May-30 21:21 UTC
Re: Noticeably poor Intel GPU performance on 3.3 and 3.4 dom0 kernels
On Wed, May 30, 2012 at 04:57:00PM +0200, Marek Marczykowski wrote:> On 30.05.2012 16:28, Konrad Rzeszutek Wilk wrote: > > On Wed, May 30, 2012 at 12:14:07PM +0200, Joanna Rutkowska wrote: > >> Hello, > >> > >> I''ve recently been some newer Dom0 kernels (3.3.5, 3.4) under Xen 4.1.2, > >> and have noticed that those kernel noticeably downgrade performance of > >> (at least) Intel GPUs. This is easily noticeable even on such trivial > >> tasks as scrolling a webpage in Firefox or Chrome. This slow GPU > >> performance on 3.3 and 3.4 kernels is in stark contrast with what I see > >> on 3.2.7 Dom0 kernel, where graphics works just great... > >> > >> In order to make sure that this is not caused by power management set > >> too strictly, I played with xenpm and made sure to set the following: > > > > And are you building with CONFIG_INTEL_IOMMU=y? > > Yes: > CONFIG_GART_IOMMU=y > # CONFIG_CALGARY_IOMMU is not set > CONFIG_SWIOTLB=y > CONFIG_IOMMU_HELPER=y > (...) > CONFIG_IOMMU_API=y > CONFIG_IOMMU_SUPPORT=y > CONFIG_AMD_IOMMU=y > # CONFIG_AMD_IOMMU_STATS is not set > CONFIG_AMD_IOMMU_V2=m > CONFIG_DMAR_TABLE=y > CONFIG_INTEL_IOMMU=y > CONFIG_INTEL_IOMMU_DEFAULT_ON=y > CONFIG_INTEL_IOMMU_FLOPPY_WA=y > CONFIG_IRQ_REMAP=yIn that case I think you might need to do some git bisection to figure out which patch caused the slow-down. Are there any obvious things in the kernel logs (you might have to boot it with loglevel=8 debug)?
Joanna Rutkowska
2012-May-31 09:15 UTC
Re: Noticeably poor Intel GPU performance on 3.3 and 3.4 dom0 kernels
On 05/30/12 12:37, Jan Beulich wrote:>>>> On 30.05.12 at 12:14, Joanna Rutkowska <joanna@invisiblethingslab.com> wrote: >> > I''ve recently been some newer Dom0 kernels (3.3.5, 3.4) under Xen 4.1.2, >> > and have noticed that those kernel noticeably downgrade performance of >> > (at least) Intel GPUs. This is easily noticeable even on such trivial >> > tasks as scrolling a webpage in Firefox or Chrome. This slow GPU >> > performance on 3.3 and 3.4 kernels is in stark contrast with what I see >> > on 3.2.7 Dom0 kernel, where graphics works just great... >> > >> > In order to make sure that this is not caused by power management set >> > too strictly, I played with xenpm and made sure to set the following: >> > 1) xenpm set-scaling-governor performance >> > 2) xenpm set-max-cstate 0 >> > >> > I have verified then that my processor: 1) keeps staying in P0 state >> > (so, max frequency), and 2) keeps staying in C0 state. >> > >> > Those setting didn''t change anything regarding the poor graphics >> > performance, though. >> > >> > Any ideas what else I could test to find out the cause of this? > To check whether the DRM drivers'' supposedly more extensive > use of the DMA API is the reason, could you check whether the > performance is as bad with "mem=4G" on the Xen command line?With mem=4G xen option, the graphics performance is just as poor as without. joanna. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel