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2016-02-11s390/diag: avoid lockdep recursionHeiko Carstens
The diagnose tracer will indirectly call back into the lockdep code when lockdep does not expect it (arch_spinlock). This causes lockdep to disable itself and therefore we don't have a working lock dependency validator anymore. This patch effectively disables tracing of diag 0x9c and 0x44 if lockdep is enabled. If however lockdep is enabled spinlocks are mainly implemented using a trylock variant, which will not issue any diag 0x9c or 0x44. So this change has hardly any effect on tracing except when arch_spinlock and friends are explicitly used. Reported-and-Tested-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-11-09s390/diag: add a s390 prefix to the diagnose trace pointMartin Schwidefsky
Documentation/trace/tracepoints.txt states that the naming scheme for tracepoints is "subsys_event" to avoid collisions. Rename the 'diagnose' tracepoint to 's390_diagnose'. Reported-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-10-14s390/diag: add tracepoint for diagnose callsMartin Schwidefsky
To be able to analyse problems in regard to hypervisor overhead add a tracepoing for diagnose calls. It reports the number of the diagnose issued, e.g. sshd-1385 [002] .... 42.701431: diagnose: nr=0x9c <idle>-0 [001] ..s. 43.587528: diagnose: nr=0x9c Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>