Re: [KVM-AUTOTEST PATCH] KVM test: Add hugepage variant

[Ryan Harper <ryanh@us.ibm.com>]

* Lucas Meneghel Rodrigues <lmr@redhat.com> [2009-07-28 22:40]:
> This patch adds a small setup script to set up huge memory
> pages during the kvm tests execution. Also, added hugepage setup to the
> fc8_quick sample.
> 
> Signed-off-by: Luká?? Doktor <ldoktor@redhat.com>
> Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>

Looks good.  one nit below.

Signed-off-by: Ryan Harper <ryanh@us.ibm.com>

> ---
>  client/tests/kvm/kvm_tests.cfg.sample |    8 +++
>  client/tests/kvm/kvm_vm.py            |   11 +++
>  client/tests/kvm/scripts/hugepage.py  |  109 +++++++++++++++++++++++++++++++++
>  3 files changed, 128 insertions(+), 0 deletions(-)
>  create mode 100644 client/tests/kvm/scripts/hugepage.py
> 
> diff --git a/client/tests/kvm/kvm_tests.cfg.sample b/client/tests/kvm/kvm_tests.cfg.sample
> index 2d75a66..7cd12cb 100644
> --- a/client/tests/kvm/kvm_tests.cfg.sample
> +++ b/client/tests/kvm/kvm_tests.cfg.sample
> @@ -587,6 +587,13 @@ variants:
> 
> 
>  variants:
> +    - @kvm_smallpages:
> +    - kvm_hugepages:
> +        pre_command = "/usr/bin/python scripts/hugepage.py /mnt/kvm_hugepage"
> +        extra_params += " -mem-path /mnt/kvm_hugepage"
> +
> +
> +variants:
>      - @basic:
>          only Fedora Windows
>      - @full:
> @@ -598,6 +605,7 @@ variants:
>          only Fedora.8.32
>          only install setup boot shutdown
>          only rtl8139
> +        only kvm_hugepages
>      - @sample1:
>          only qcow2
>          only ide
> diff --git a/client/tests/kvm/kvm_vm.py b/client/tests/kvm/kvm_vm.py
> index d96b359..eba9b84 100644
> --- a/client/tests/kvm/kvm_vm.py
> +++ b/client/tests/kvm/kvm_vm.py
> @@ -397,6 +397,17 @@ class VM:
>                  self.destroy()
>                  return False
> 
> +            # Get the output so far, to see if we have any problems with
> +            # hugepage setup.
> +            output = self.process.get_output()
> +
> +            if "alloc_mem_area" in output:
> +                logging.error("Could not allocate hugepage memory; "
> +                              "qemu command:\n%s" % qemu_command)
> +                logging.error("Output:" + kvm_utils.format_str_for_message(
> +                              self.process.get_output()))
> +                return False
> +
>              logging.debug("VM appears to be alive with PID %d",
>                            self.process.get_pid())
>              return True
> diff --git a/client/tests/kvm/scripts/hugepage.py b/client/tests/kvm/scripts/hugepage.py
> new file mode 100644
> index 0000000..dc36da4
> --- /dev/null
> +++ b/client/tests/kvm/scripts/hugepage.py
> @@ -0,0 +1,109 @@
> +#!/usr/bin/python
> +# -*- coding: utf-8 -*-
> +import os, sys, time
> +
> +"""
> +Simple script to allocate enough hugepages for KVM testing purposes.
> +"""
> +
> +class HugePageError(Exception):
> +    """
> +    Simple wrapper for the builtin Exception class.
> +    """
> +    pass
> +
> +
> +class HugePage:
> +    def __init__(self, hugepage_path=None):
> +        """
> +        Gets environment variable values and calculates the target number
> +        of huge memory pages.
> +
> +        @param hugepage_path: Path where to mount hugetlbfs path, if not
> +                yet configured.
> +        """
> +        self.vms = len(os.environ['KVM_TEST_vms'].split())
> +        self.mem = int(os.environ['KVM_TEST_mem'])
> +        try:
> +            self.max_vms = int(os.environ['KVM_TEST_max_vms'])
> +        except KeyError:
> +            self.max_vms = 0
> +
> +        if hugepage_path:
> +            self.hugepage_path = hugepage_path
> +        else:
> +            self.hugepage_path = '/mnt/kvm_hugepage'
> +
> +        self.hugepage_size = self.get_hugepage_size()
> +        self.target_hugepages = self.get_target_hugepages()
> +
> +
> +    def get_hugepage_size(self):
> +        """
> +        Get the current system setting for huge memory page size.
> +        """
> +        meminfo = open('/proc/meminfo', 'r').readlines()
> +        huge_line_list = [h for h in meminfo if h.startswith("Hugepagesize")]
> +        try:
> +            return int(huge_line_list[0].split()[1])
> +        except ValueError, e:
> +            raise HugePageError("Could not get huge page size setting from "
> +                                "/proc/meminfo: %s" % e)
> +
> +
> +    def get_target_hugepages(self):
> +        """
> +        Calculate the target number of hugepages for testing purposes.
> +        """
> +        if self.vms < self.max_vms:
> +            self.vms = self.max_vms
> +        vmsm = (self.vms * self.mem) + (self.vms * 64)

Nit: Maybe a comment about the fudge factor being added in?

> +        return int(vmsm * 1024 / self.hugepage_size)
> +
> +
> +    def set_hugepages(self):
> +        """
> +        Sets the hugepage limit to the target hugepage value calculated.
> +        """
> +        hugepage_cfg = open("/proc/sys/vm/nr_hugepages", "r+")
> +        hp = hugepage_cfg.readline()
> +        while int(hp) < self.target_hugepages:
> +            loop_hp = hp
> +            hugepage_cfg.write(str(self.target_hugepages))
> +            hugepage_cfg.flush()
> +            hugepage_cfg.seek(0)
> +            hp = int(hugepage_cfg.readline())
> +            if loop_hp == hp:
> +                raise HugePageError("Cannot set the kernel hugepage setting "
> +                                    "to the target value of %d hugepages." %
> +                                    self.target_hugepages)
> +        hugepage_cfg.close()
> +
> +
> +    def mount_hugepage_fs(self):
> +        """
> +        Verify if there's a hugetlbfs mount set. If there's none, will set up
> +        a hugetlbfs mount using the class attribute that defines the mount
> +        point.
> +        """
> +        if not os.path.ismount(self.hugepage_path):
> +            if not os.path.isdir(self.hugepage_path):
> +                os.makedirs(self.hugepage_path)
> +            cmd = "mount -t hugetlbfs none %s" % self.hugepage_path
> +            if os.system(cmd):
> +                raise HugePageError("Cannot mount hugetlbfs path %s" %
> +                                    self.hugepage_path)
> +
> +
> +    def setup(self):
> +        self.set_hugepages()
> +        self.mount_hugepage_fs()
> +
> +
> +if __name__ == "__main__":
> +    if len(sys.argv) < 2:
> +        huge_page = HugePage()
> +    else:
> +        huge_page = HugePage(sys.argv[1])
> +
> +    huge_page.setup()
> -- 
> 1.6.2.5
> 
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-- 
Ryan Harper
Software Engineer; Linux Technology Center
IBM Corp., Austin, Tx
ryanh@us.ibm.com