linux/arch/s390
Hendrik Brueckner d4c7e649d7 s390/cpum_sf: load program parameter at sampler enablement
The lpp instruction is used to place the PID of the current
task in the program-parameter (PP) register.  The register
contents is then included in the sampling data entries.

The lpp instruction loads the PP register only when at least
one sampling function is enabled.  Otherwise it is executed
as a no-op.

Linux calls lpp at context switch.  If the context switch
happens before the sampler is enabled, the PP register is
empty.  That means, the PID of the task that is sampled is
not stored in sampling data until the next context switch.

Hence, always call lpp when enabling the sampler.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-16 15:06:16 +01:00
..
appldata
boot Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2017-11-13 11:47:01 -08:00
configs s390: Remove CONFIG_HARDENED_USERCOPY 2017-11-16 13:12:21 +01:00
crypto Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2017-11-13 11:47:01 -08:00
hypfs
include s390/cpum_sf: load program parameter at sampler enablement 2017-11-16 15:06:16 +01:00
kernel s390/cpum_sf: load program parameter at sampler enablement 2017-11-16 15:06:16 +01:00
kvm Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2017-11-13 11:47:01 -08:00
lib s390/spinlock: fix indentation 2017-11-14 22:07:58 +01:00
mm s390/mm: remove unused code 2017-11-14 22:08:05 +01:00
net Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2017-11-13 11:47:01 -08:00
numa
oprofile
pci Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2017-11-13 11:47:01 -08:00
tools Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2017-11-13 11:47:01 -08:00
defconfig
Kbuild
Kconfig s390/perf: add perf_regs support and user stack dump 2017-11-16 15:06:11 +01:00
Kconfig.debug
Makefile