Re: Perf event operation with hotplug cpus and cgroups

2015-03-23 Thread William Cohen
On 03/20/2015 04:20 PM, Peter Zijlstra wrote: > On Fri, Mar 20, 2015 at 03:41:54PM -0400, William Cohen wrote: >> >> There isn't any desire to aggregate the different cgroup data >> together. The desired grouping is measurements per cgroup, kind of >> like the pid scoping for perf but for a cgroup.

Re: Perf event operation with hotplug cpus and cgroups

2015-03-20 Thread Peter Zijlstra
On Fri, Mar 20, 2015 at 03:41:54PM -0400, William Cohen wrote: > > There isn't any desire to aggregate the different cgroup data > together. The desired grouping is measurements per cgroup, kind of > like the pid scoping for perf but for a cgroup. It is just that the > way that the perf event mea

Re: Perf event operation with hotplug cpus and cgroups

2015-03-20 Thread William Cohen
On 03/20/2015 03:22 PM, Peter Zijlstra wrote: > On Fri, Mar 20, 2015 at 03:10:39PM -0400, William Cohen wrote: >> cgroup monitoring >> >> The cgroup monitoring is built on the perf event per cpu monitoring. >> If the cgroup is not pinned to a particular set of processors, then >> systemwide monitor

Re: Perf event operation with hotplug cpus and cgroups

2015-03-20 Thread Peter Zijlstra
On Fri, Mar 20, 2015 at 03:10:39PM -0400, William Cohen wrote: > cgroup monitoring > > The cgroup monitoring is built on the perf event per cpu monitoring. > If the cgroup is not pinned to a particular set of processors, then > systemwide monitoring for that cgroup needs to be done and a perf > ev

Perf event operation with hotplug cpus and cgroups

2015-03-20 Thread William Cohen
The current perf event interface avoids complexity in the kernel by making the user-space responsible for opening a file descriptor for each cpu to monitor performance events. However, there are two use cases where this approach has issues: handling system-wide measurements with hotplug cpus and m