linux/arch
Ard Biesheuvel 8769177658 ARM: vfp: Record VFP bounces as perf emulation faults
VFP 'bouncing' occurs when the VFP unit cannot complete the execution of
a VFP instruction, either because it is not implemented at all, or
because the values of the arguments are out of range for the hardware
implementation, and the software needs to step in to complete the
operation.

To give some insight in how much certain programs rely on this bouncing,
record the emulation of a VFP instruction in perf's emulation-faults
counter.

This can be used like so

  perf stat -e emulation-faults ./testfloat -all2

and the output will be something like

 Performance counter stats for './testfloat -all2':

           259,277      emulation-faults:u

       6.846432176 seconds time elapsed

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-05-16 20:24:08 +02:00
..
alpha Locking changes in v6.4: 2023-05-05 12:56:55 -07:00
arc Locking changes in v6.4: 2023-05-05 12:56:55 -07:00
arm ARM: vfp: Record VFP bounces as perf emulation faults 2023-05-16 20:24:08 +02:00
arm64 Locking changes in v6.4: 2023-05-05 12:56:55 -07:00
csky arch/csky patches for 6.4 2023-05-04 12:25:05 -07:00
hexagon Locking changes in v6.4: 2023-05-05 12:56:55 -07:00
ia64 Locking changes in v6.4: 2023-05-05 12:56:55 -07:00
loongarch Locking changes in v6.4: 2023-05-05 12:56:55 -07:00
m68k Locking changes in v6.4: 2023-05-05 12:56:55 -07:00
microblaze Kconfig: introduce HAS_IOPORT option and select it as necessary 2023-04-05 22:15:19 +02:00
mips Locking changes in v6.4: 2023-05-05 12:56:55 -07:00
nios2 - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of 2023-04-27 19:42:02 -07:00
openrisc Locking changes in v6.4: 2023-05-05 12:56:55 -07:00
parisc parisc: Fix encoding of swp_entry due to added SWP_EXCLUSIVE flag 2023-05-14 02:04:27 +02:00
powerpc Locking changes in v6.4: 2023-05-05 12:56:55 -07:00
riscv riscv: Fix orphan section warnings caused by kernel/pi 2023-05-09 18:20:23 -07:00
s390 s390: remove the unneeded select GCC12_NO_ARRAY_BOUNDS 2023-05-05 18:56:23 -07:00
sh Locking changes in v6.4: 2023-05-05 12:56:55 -07:00
sparc Locking changes in v6.4: 2023-05-05 12:56:55 -07:00
um This pull request contains the following changes for UML: 2023-05-03 19:02:03 -07:00
x86 - Make sure the PEBS buffer is flushed before reprogramming the hardware 2023-05-14 07:56:51 -07:00
xtensa Locking changes in v6.4: 2023-05-05 12:56:55 -07:00
.gitignore
Kconfig