Files
s390-tools/zdev
Alexandra Winter 6d06921276 zdev:qeth: adapt performance_stats attribute semantics
Behaviour of the qeth performance_stats sysfs attribute has changed
with kernel commit
b0abc4f5df76 ("s390/qeth: overhaul ethtool statistics")
that went into kernel v5.1.

Before the kernel commit
- collection of statistics was turned on and off by writing 1 or 0
- default after device activation was 0
- statistics were reset by writing 0

After the kernel commit:
- collection is always on
- attribute always reads 1
- statistics is reset by writing 1; writing 0 is a no-op

Problems of chzdev on new kernels:
chzdev cannot reset statistics ('performance_stats=1' does nothing).
'chzdev --export' always lists performance_stats.
'chzdev qeth --help-attribute performance_stats' reflects old behaviour.

This patch will do the following:
'chzdev qeth --help-attribute performance_stats' reflects new behaviour.
'chzdev --export' does not list performance_stats on new kernels.
'chzdev performance_stats=1' resets statistics on new kernels.
'chzdev performance_stats=0' still resets statistics on old kernels,
    does nothing on new kernels.

Suggested-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
2023-11-07 14:13:38 +01:00
..