Re: [PATCH 1/6] rteval: Detect isolcpus in systopology

[John Kacur <jkacur@redhat.com>]

On Fri, 30 Jun 2023, Tomas Glozar wrote:

> Works similarly to online_cpus:
> - add CpuList.isolated_cpulist to filter isolated CPUs
> - add SysTopology.isolated_cpus to get list of isolated CPUs
> - add CpuList.nonisolated_cpulist to do the opposite filter
> - add SysTopology.default_cpus to get CPUs that are used for scheduling
>   by default, i.e. online and non-isolated CPUs
> 
> Signed-off-by: Tomas Glozar <tglozar@redhat.com>
> ---
>  rteval/systopology.py | 47 +++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 47 insertions(+)
> 
> diff --git a/rteval/systopology.py b/rteval/systopology.py
> index c8f85c5..19443f9 100644
> --- a/rteval/systopology.py
> +++ b/rteval/systopology.py
> @@ -127,6 +127,11 @@ class CpuList:
>              return True
>          return False
>  
> +    @staticmethod
> +    def isolated_file_exists():
> +        """ Check whether machine / kernel is configured with isolated file """
> +        return os.path.exists(os.path.join(CpuList.cpupath, "isolated"))
> +
>      @staticmethod
>      def longest_sequence(cpulist):
>          """ return index of last element of a sequence that steps by one """
> @@ -214,6 +219,24 @@ class CpuList:
>                  newlist.append(cpu)
>          return newlist
>  
> +    @staticmethod
> +    def isolated_cpulist(cpulist):
> +        """Given a cpulist, return a cpulist of isolated CPUs"""
> +        if not CpuList.isolated_file_exists():
> +            return cpulist
> +        isolated_cpulist = sysread(CpuList.cpupath, "isolated")
> +        isolated_cpulist = CpuList.expand_cpulist(isolated_cpulist)
> +        return list(set(isolated_cpulist) & set(cpulist))
> +
> +    @staticmethod
> +    def nonisolated_cpulist(cpulist):
> +        """Given a cpulist, return a cpulist of non-isolated CPUs"""
> +        if not CpuList.isolated_file_exists():
> +            return cpulist
> +        isolated_cpulist = sysread(CpuList.cpupath, "isolated")
> +        isolated_cpulist = CpuList.expand_cpulist(isolated_cpulist)
> +        return list(set(cpulist).difference(set(isolated_cpulist)))
> +
>  #
>  # class to abstract access to NUMA nodes in /sys filesystem
>  #
> @@ -362,11 +385,35 @@ class SysTopology:
>          cpulist.sort()
>          return cpulist
>  
> +    def isolated_cpus(self):
> +        """ return a list of integers of all isolated cpus """
> +        cpulist = []
> +        for n in self.nodes:
> +            cpulist += CpuList.isolated_cpulist(self.getcpus(n))
> +        cpulist.sort()
> +        return cpulist
> +
> +    def default_cpus(self):
> +        """ return a list of integers of all default schedulable cpus, i.e. online non-isolated cpus """
> +        cpulist = []
> +        for n in self.nodes:
> +            cpulist += CpuList.nonisolated_cpulist(self.getcpus(n))
> +        cpulist.sort()
> +        return cpulist
> +
>      def online_cpus_str(self):
>          """ return a list of strings of numbers of all online cpus """
>          cpulist = [str(cpu) for cpu in self.online_cpus()]
>          return cpulist
>  
> +    def isolated_cpus_str(self):
> +        cpulist = [str(cpu) for cpu in self.isolated_cpus()]
> +        return cpulist
> +
> +    def default_cpus_str(self):
> +        cpulist = [str(cpu) for cpu in self.default_cpus()]
> +        return cpulist
> +
>      def invert_cpulist(self, cpulist):
>          """ return a list of online cpus not in cpulist """
>          return [c for c in self.online_cpus() if c not in cpulist]
> -- 
> 2.41.0
> 
> 
Signed-off-by: John Kacur <jkacur@redhat.com>
--
The code is good, but I don't love the name "default_cpus", but it will 
do. isolated_cpus_str() and default_cpus_str() require docstrings.
I'm signing off on this to move it forward so please send that in a 
separate patch.