[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Xen-devel] Re: [Xen-ia64-devel] [PATCH][IA64] configure VHPT size per HVM domain



Hi Kouya.

I guess Linux PV domains (especially dom0) possibly can gain similar
performance improvement by increasing VHPT size too.
So would it be easy to make vhpt parameter non hvm specific?
I know your concern is hvm domain, though.

On Tue, Oct 16, 2007 at 03:21:39PM +0900, Kouya Shimura wrote:
Content-Description: message body text
> Hi Keir and Alex,
> 
> A Virtual Hash Page Table(VHPT) is a special feature of IA64.
> It's an extension of TLB that resides in memory and can be 
> automatically searched by the processor.
> 
> This patch allows user to configure VHPT size per HVM domain.
> 
> We have an interesting result.
> We tried some large transaction benchmark,
> for VHPT size in 512K, 2M, 4M, 8M:
>  - Linux is getting a better score (totally 20% up)
>  - Windows is getting a worse score (totally 10% down)
> 
> The reason of windows degradation is, windows OS flushes 
> TLB more frequently. Xen hypervisor must clear the memory of VHPT
> with TLB flushing, that becomes an overhead.
> 
> This patch is significant for IA64 to support both linux guest
> and windows guest simultaneously.
> 
> Thanks,
> Kouya
> 
> Signed-off-by: Kouya Shimura <kouya@xxxxxxxxxxxxxx>
> 

> diff -r 2863852e02f6 tools/examples/xmexample.vti
> --- a/tools/examples/xmexample.vti    Mon Oct 15 11:41:28 2007 -0600
> +++ b/tools/examples/xmexample.vti    Tue Oct 16 11:31:53 2007 +0900
> @@ -34,6 +34,10 @@ name = "ExampleVTIDomain"
>  #cpus = ""         # leave to Xen to pick
>  #cpus = "0"        # all vcpus run on CPU0
>  #cpus = "0-3,5,^1" # run on cpus 0,2,3,5
> +
> +# VHPT size(2**n), default=23 (8MB), minimum=15 (32KB).
> +# In Windows OS, smaller size shows better performance.
> +#vhpt = 23
>  
>  # Optionally define mac and/or bridge for the network interfaces.
>  # Random MACs are assigned if not given.
> diff -r 2863852e02f6 tools/python/xen/lowlevel/xc/xc.c
> --- a/tools/python/xen/lowlevel/xc/xc.c       Mon Oct 15 11:41:28 2007 -0600
> +++ b/tools/python/xen/lowlevel/xc/xc.c       Tue Oct 16 10:03:46 2007 +0900
> @@ -538,15 +538,20 @@ static PyObject *pyxc_hvm_build(XcObject
>  #endif
>      char *image;
>      int store_evtchn, memsize, vcpus = 1, pae = 0, acpi = 0, apic = 1;
> +    int vhpt = 0;
>      unsigned long store_mfn;
>  
>      static char *kwd_list[] = { "domid", "store_evtchn",
>                               "memsize", "image", "vcpus", "pae", "acpi",
> -                             "apic", NULL };
> -    if ( !PyArg_ParseTupleAndKeywords(args, kwds, "iiis|iiii", kwd_list,
> -                                      &dom, &store_evtchn, &memsize,
> -                                      &image, &vcpus, &pae, &acpi, &apic) )
> -        return NULL;
> +                             "apic", "vhpt", NULL };
> +    if ( !PyArg_ParseTupleAndKeywords(args, kwds, "iiis|iiiii", kwd_list,
> +                                      &dom, &store_evtchn, &memsize, &image,
> +                                      &vcpus, &pae, &acpi, &apic, &vhpt) )
> +        return NULL;
> +
> +#ifdef __ia64__
> +    xc_set_hvm_param(self->xc_handle, dom, HVM_PARAM_VHPT_SIZE, vhpt);
> +#endif
>  
>      if ( xc_hvm_build(self->xc_handle, dom, memsize, image) != 0 )
>          return pyxc_error_to_exception();
> diff -r 2863852e02f6 tools/python/xen/xend/XendConfig.py
> --- a/tools/python/xen/xend/XendConfig.py     Mon Oct 15 11:41:28 2007 -0600
> +++ b/tools/python/xen/xend/XendConfig.py     Tue Oct 16 10:21:25 2007 +0900
> @@ -127,7 +127,7 @@ XENAPI_PLATFORM_CFG = [ 'acpi', 'apic', 
>                          'nographic', 'pae', 'rtc_timeoffset', 'serial', 
> 'sdl',
>                          'soundhw','stdvga', 'usb', 'usbdevice', 'vnc',
>                          'vncconsole', 'vncdisplay', 'vnclisten',
> -                        'vncpasswd', 'vncunused', 'xauthority', 'pci']
> +                        'vncpasswd', 'vncunused', 'xauthority', 'pci', 
> 'vhpt']
>  
>  # Xen API console 'other_config' keys.
>  XENAPI_CONSOLE_OTHER_CFG = ['vncunused', 'vncdisplay', 'vnclisten',
> diff -r 2863852e02f6 tools/python/xen/xend/image.py
> --- a/tools/python/xen/xend/image.py  Mon Oct 15 11:41:28 2007 -0600
> +++ b/tools/python/xen/xend/image.py  Tue Oct 16 10:03:46 2007 +0900
> @@ -277,6 +277,7 @@ class HVMImageHandler(ImageHandler):
>          self.pae  = int(vmConfig['platform'].get('pae',  0))
>          self.apic = int(vmConfig['platform'].get('apic', 0))
>          self.acpi = int(vmConfig['platform'].get('acpi', 0))
> +        self.vhpt = int(vmConfig['platform'].get('vhpt', 0))
>          
>  
>      def buildDomain(self):
> @@ -292,6 +293,7 @@ class HVMImageHandler(ImageHandler):
>          log.debug("pae            = %d", self.pae)
>          log.debug("acpi           = %d", self.acpi)
>          log.debug("apic           = %d", self.apic)
> +        log.debug("vhpt           = %d", self.vhpt)
>  
>          rc = xc.hvm_build(domid          = self.vm.getDomid(),
>                            image          = self.kernel,
> @@ -300,7 +302,8 @@ class HVMImageHandler(ImageHandler):
>                            vcpus          = self.vm.getVCpuCount(),
>                            pae            = self.pae,
>                            acpi           = self.acpi,
> -                          apic           = self.apic)
> +                          apic           = self.apic,
> +                          vhpt           = self.vhpt)
>          rc['notes'] = { 'SUSPEND_CANCEL': 1 }
>          return rc
>  
> diff -r 2863852e02f6 tools/python/xen/xm/create.py
> --- a/tools/python/xen/xm/create.py   Mon Oct 15 11:41:28 2007 -0600
> +++ b/tools/python/xen/xm/create.py   Tue Oct 16 11:22:10 2007 +0900
> @@ -209,6 +209,10 @@ gopts.var('vcpu_avail', val='VCPUS',
>  gopts.var('vcpu_avail', val='VCPUS',
>            fn=set_long, default=None,
>            use="Bitmask for virtual CPUs to make available immediately.")
> +
> +gopts.var('vhpt', val='VHPT',
> +          fn=set_int, default=0,
> +          use="VHPT Size(2**n) of IA64 HVM domain.")
>  
>  gopts.var('cpu_cap', val='CAP',
>            fn=set_int, default=None,
> @@ -721,7 +725,7 @@ def configure_hvm(config_image, vals):
>               'localtime', 'serial', 'stdvga', 'isa', 'nographic', 'soundhw',
>               'vnc', 'vncdisplay', 'vncunused', 'vncconsole', 'vnclisten',
>               'sdl', 'display', 'xauthority', 'rtc_timeoffset', 'monitor',
> -             'acpi', 'apic', 'usb', 'usbdevice', 'keymap', 'pci' ]
> +             'acpi', 'apic', 'usb', 'usbdevice', 'keymap', 'pci', 'vhpt' ]
>      for a in args:
>          if a in vals.__dict__ and vals.__dict__[a] is not None:
>              config_image.append([a, vals.__dict__[a]])
> diff -r 2863852e02f6 xen/arch/ia64/vmx/vmmu.c
> --- a/xen/arch/ia64/vmx/vmmu.c        Mon Oct 15 11:41:28 2007 -0600
> +++ b/xen/arch/ia64/vmx/vmmu.c        Tue Oct 16 10:12:40 2007 +0900
> @@ -96,8 +96,14 @@ static int init_domain_vhpt(struct vcpu 
>  static int init_domain_vhpt(struct vcpu *v)
>  {
>      int rc;
> -
> -    rc = thash_alloc(&(v->arch.vhpt), default_vhpt_sz, "vhpt");
> +    u64 size = v->domain->arch.hvm_domain.params[HVM_PARAM_VHPT_SIZE];
> +
> +    if (size == 0)
> +        size = default_vhpt_sz;
> +    else
> +        size = canonicalize_vhpt_size(size);
> +
> +    rc = thash_alloc(&(v->arch.vhpt), size, "vhpt");
>      v->arch.arch_vmx.mpta = v->arch.vhpt.pta.val;
>      return rc;
>  }
> diff -r 2863852e02f6 xen/include/public/hvm/params.h
> --- a/xen/include/public/hvm/params.h Mon Oct 15 11:41:28 2007 -0600
> +++ b/xen/include/public/hvm/params.h Tue Oct 16 10:03:54 2007 +0900
> @@ -52,7 +52,8 @@
>  
>  #ifdef __ia64__
>  #define HVM_PARAM_NVRAM_FD     7
> -#define HVM_NR_PARAMS          8
> +#define HVM_PARAM_VHPT_SIZE    8
> +#define HVM_NR_PARAMS          9
>  #else
>  #define HVM_NR_PARAMS          7
>  #endif

> _______________________________________________
> Xen-ia64-devel mailing list
> Xen-ia64-devel@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-ia64-devel

-- 
yamahata

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel


 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.