diff options
| author |   José Pekkarinen <jose.pekkarinen@nokia.com> | 2016-04-11 10:41:07 +0300 |
|---|---|---|
| committer | José Pekkarinen <jose.pekkarinen@nokia.com> | 2016-04-13 08:17:18 +0300 |
| commit | e09b41010ba33a20a87472ee821fa407a5b8da36 (patch) | |
| tree | d10dc367189862e7ca5c592f033dc3726e1df4e3 /kernel/Documentation/arm/CCN.txt | |
| parent | f93b97fd65072de626c074dbe099a1fff05ce060 (diff) | |
These changes are the raw update to linux-4.4.6-rt14. Kernel sources
are taken from kernel.org, and rt patch from the rt wiki download page.
During the rebasing, the following patch collided:
Force tick interrupt and get rid of softirq magic(I70131fb85).
Collisions have been removed because its logic was found on the
source already.
Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769
Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>
Diffstat (limited to 'kernel/Documentation/arm/CCN.txt')
| -rw-r--r-- | kernel/Documentation/arm/CCN.txt | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/kernel/Documentation/arm/CCN.txt b/kernel/Documentation/arm/CCN.txt index 0632b3aad..ffca443a1 100644 --- a/kernel/Documentation/arm/CCN.txt +++ b/kernel/Documentation/arm/CCN.txt @@ -33,20 +33,23 @@ directory, with first 8 configurable by user and additional Cycle counter is described by a "type" value 0xff and does not require any other settings. +The driver also provides a "cpumask" sysfs attribute, which contains +a single CPU ID, of the processor which will be used to handle all +the CCN PMU events. It is recommended that the user space tools +request the events on this processor (if not, the perf_event->cpu value +will be overwritten anyway). In case of this processor being offlined, +the events are migrated to another one and the attribute is updated. + Example of perf tool use: / # perf list | grep ccn ccn/cycles/ [Kernel PMU event] <...> - ccn/xp_valid_flit/ [Kernel PMU event] + ccn/xp_valid_flit,xp=?,port=?,vc=?,dir=?/ [Kernel PMU event] <...> -/ # perf stat -C 0 -e ccn/cycles/,ccn/xp_valid_flit,xp=1,port=0,vc=1,dir=1/ \ +/ # perf stat -a -e ccn/cycles/,ccn/xp_valid_flit,xp=1,port=0,vc=1,dir=1/ \ sleep 1 The driver does not support sampling, therefore "perf record" will -not work. Also notice that only single cpu is being selected -("-C 0") - this is because perf framework does not support -"non-CPU related" counters (yet?) so system-wide session ("-a") -would try (and in most cases fail) to set up the same event -per each CPU. +not work. Per-task (without "-a") perf sessions are not supported. |