linux/arch/s390
Jan Glauber e4b8b3f33f s390: add support for runtime instrumentation
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>
2012-09-26 15:45:02 +02:00
..
appldata s390/vtimer: rework virtual timer interface 2012-07-20 11:15:08 +02:00
boot s390/string: provide asm lib functions for memcpy and memcmp 2012-09-26 15:44:50 +02:00
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2012-07-26 13:00:59 -07:00
hypfs s390/comments: unify copyright messages and remove file names 2012-07-20 11:15:04 +02:00
include/asm s390: add support for runtime instrumentation 2012-09-26 15:45:02 +02:00
kernel s390: add support for runtime instrumentation 2012-09-26 15:45:02 +02:00
kvm s390/kconfig: split the s390 base menu 2012-09-26 15:44:51 +02:00
lib s390/string: provide asm lib functions for memcpy and memcmp 2012-09-26 15:44:50 +02:00
math-emu s390/comments: unify copyright messages and remove file names 2012-07-20 11:15:04 +02:00
mm s390/cpu hotplug: mask out CPU_TASKS_FROZEN in cu hotplug notifiers 2012-09-26 15:44:53 +02:00
net s390/bpf,jit: improve code generation 2012-09-26 15:44:49 +02:00
oprofile oprofile, s390: Fix uninitialized memory access when writing to oprofilefs 2012-08-27 14:49:23 +02:00
defconfig Merge branch 'akpm' (Andrew's patch-bomb) 2012-07-31 19:25:39 -07:00
Kbuild s390/bpf,jit: BPF Just In Time compiler for s390 2012-09-26 15:44:49 +02:00
Kconfig s390/cio: add eadm subchannel driver 2012-09-26 15:45:00 +02:00
Kconfig.debug [S390] Write protect module text and RO data 2011-03-15 17:08:23 +01:00
Makefile s390: Use generic init_task 2012-05-05 13:00:25 +02:00