Improve uprobes performance by adding 'pre-filtering' support,
by Oleg Nesterov:
# time perl -e 'syscall -1 for 1..100_000'
real 0m0.040s
user 0m0.027s
sys 0m0.010s
# perf probe -x /lib/libc.so.6 syscall
# perf record -e probe_libc:syscall sleep 100 &
Before this series:
# time perl -e 'syscall -1 for 1..100_000'
real 0m1.714s
user 0m0.103s
sys 0m1.607s
After:
# time perl -e 'syscall -1 for 1..100_000'
real 0m0.037s
user 0m0.013s
sys 0m0.023s
Signed-off-by: Ingo Molnar <mingo@kernel.org>