lkml.org 
[lkml]   [2013]   [Jan]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH 0/2] perf: add new uncore command
From
On Thu, Jan 31, 2013 at 3:21 PM, Ingo Molnar <mingo@kernel.org> wrote:
>
> * Stephane Eranian <eranian@google.com> wrote:
>
>> This patchset adds a new command to perf: perf uncore.
>> It is used to measure processor socket-level metrics
>> on a system-wide basis and at all priv levels.
>>
>> The command comes with a set of predefined key metrics
>> which are useful to measure multi-socket system imbalance
>> and various bandwidths.
>>
>> The following metrics are currently defined:
>> - memory bandwidth (Nehalem, Westmere, SandyBridge-EP)
>> - PCIe bandwidth (SandyBridge-EP)
>> - QPI bandwidth (SandyBridge-EP)
>> - C-state residency (SandyBridge-EP)
>>
>> Others can be added in the future.
>>
>> The command provides options to modify the unit of the metrics
>> (default: MB/s for bandwidth).
>>
>> Example on Nehalem:
>>
>> # perf uncore
>> #------------------------------
>> # Socket0 |
>> #------------------------------
>> # RAM Bandwidth |
>> # Wr Rd|
>> # MB/s MB/s|
>> #------------------------------
>> 4954.99 14897.29
>> 4953.97 14894.56
>> 4947.52 14874.97
>>
>> To make plotting easier, the output can be augmented with a timestamp:
>>
>> # perf uncore -T
>> #----------------------------------------
>> # | Socket0 |
>> # |------------------------------
>> # Time | RAM Bandwidth |
>> # in | Wr Rd|
>> # secs | MB/s MB/s|
>> #----------------------------------------
>> 1 4952.50 14890.49
>> 2 4955.55 14900.19
>> 3 4949.13 14879.60
>> 4 4954.66 14896.26
>
> Looks really useful - how about naming it in a bit more generic
> way, because I'm quite sure this command will become popular and
> 'perf uncore' is a bit un-intutive.
>
> A couple of possibilities:
>
> perf system
> perf hw
> perf hw-stat
>
I am fine with that. I prefer hw or systems for the command name.

> and also adding subcommands instead of options for the various
> views/metrics, such as:
>
> perf hw ram
> perf hw pci
> perf hw qpi
> perf hw cstate

Yes, could do that. Even though having all of them measure at once
is also useful (this is how it currently works by default).

> etc.
>
> A plain 'perf hw' command would then list the available
> sub-commands and inform the user about the (current) set of
> hw subsystems that provide metrics.
>
Yes. this is what perf uncore -L already does.

For instance on SNB-EP:
$ perf uncore -L
mem_bw : SNB-EP MEM Bandwidth
qpi_bw : SNB-EP QPI Bandwidth
pcie_bw : SNB-EP PCIe Bandwidth
cstate : SNB-EP C-state residency


\
 
 \ /
  Last update: 2013-01-31 16:03    [W:0.125 / U:0.056 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site