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e4b8b3f33f
Allow user-space threads to use runtime instrumentation (RI). To enable RI for a thread there is a new s390 specific system call, sys_s390_runtime_instr, that takes as parameter a realtime signal number. If the RI facility is available the system call sets up a control block for the calling thread with the appropriate permissions for the thread to modify the control block. The user-space thread can then use the store and modify RI instructions to alter the control block and start/stop the instrumentation via RION/RIOFF. If the user specified program buffer runs full RI triggers an external interrupt. The external interrupt is translated to a real-time signal that is delivered to the thread that enabled RI on that CPU. The number of the real-time signal is the number specified in the RI system call. So, user-space can select any available real-time signal number in case the application itself uses real-time signals for other purposes. The kernel saves the RI control blocks on task switch only if the running thread was enabled for RI. Therefore, the performance impact on task switch should be negligible if RI is not used. RI is only enabled for user-space mode and is disabled for the supervisor state. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> |
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| .. | ||
| appldata | ||
| boot | ||
| crypto | ||
| hypfs | ||
| include/asm | ||
| kernel | ||
| kvm | ||
| lib | ||
| math-emu | ||
| mm | ||
| net | ||
| oprofile | ||
| defconfig | ||
| Kbuild | ||
| Kconfig | ||
| Kconfig.debug | ||
| Makefile | ||