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| author | Juergen Gross <jgross@suse.com> | 2021-03-01 11:13:34 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2021-03-06 12:49:48 +0100 |
| commit | 8d0968cc6b8ffd8496c2ebffdfdc801f949a85e5 (patch) | |
| tree | 6a6051ad28d3e33ba7fca07056bfc494823be9dd /Documentation/admin-guide | |
| parent | static_call: Fix the module key fixup (diff) | |
| download | linux-8d0968cc6b8ffd8496c2ebffdfdc801f949a85e5.tar.xz linux-8d0968cc6b8ffd8496c2ebffdfdc801f949a85e5.zip | |
locking/csd_lock: Add boot parameter for controlling CSD lock debugging
Currently CSD lock debugging can be switched on and off via a kernel
config option only. Unfortunately there is at least one problem with
CSD lock handling pending for about 2 years now, which has been seen
in different environments (mostly when running virtualized under KVM
or Xen, at least once on bare metal). Multiple attempts to catch this
issue have finally led to introduction of CSD lock debug code, but
this code is not in use in most distros as it has some impact on
performance.
In order to be able to ship kernels with CONFIG_CSD_LOCK_WAIT_DEBUG
enabled even for production use, add a boot parameter for switching
the debug functionality on. This will reduce any performance impact
of the debug coding to a bare minimum when not being used.
Signed-off-by: Juergen Gross <jgross@suse.com>
[ Minor edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210301101336.7797-2-jgross@suse.com
Diffstat (limited to 'Documentation/admin-guide')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 04545725f187..98dbffa66d89 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -784,6 +784,12 @@ cs89x0_media= [HW,NET] Format: { rj45 | aui | bnc } + csdlock_debug= [KNL] Enable debug add-ons of cross-CPU function call + handling. When switched on, additional debug data is + printed to the console in case a hanging CPU is + detected, and that CPU is pinged again in order to try + to resolve the hang situation. + dasd= [HW,NET] See header of drivers/s390/block/dasd_devmap.c. |