Ma, Chinang wrote:
> Gregory. 
> I will test the resched-ipi instrumentation patch with our OLTP if you can post the patch and some instructions.
> Thanks,
> -Chinang
>   

Hi Chinang,
  Please find a patch attached which applies to linus.git as of today. 
You will also want to enable CONFIG_FUNCTION_TRACER as well as the trace
components.  Here is my system:

ghaskins@dev:~/sandbox/git/linux-2.6-rt> grep TRACE .config
CONFIG_STACKTRACE_SUPPORT=y
CONFIG_TRACEPOINTS=y
CONFIG_HAVE_ARCH_TRACEHOOK=y
CONFIG_BLK_DEV_IO_TRACE=y
# CONFIG_TREE_RCU_TRACE is not set
# CONFIG_PREEMPT_RCU_TRACE is not set
CONFIG_X86_PTRACE_BTS=y
# CONFIG_ACPI_DEBUG_FUNC_TRACE is not set
CONFIG_NETFILTER_XT_TARGET_TRACE=m
CONFIG_SOUND_TRACEINIT=y
CONFIG_TRACE_IRQFLAGS_SUPPORT=y
CONFIG_TRACE_IRQFLAGS=y
CONFIG_STACKTRACE=y
# CONFIG_BACKTRACE_SELF_TEST is not set
CONFIG_USER_STACKTRACE_SUPPORT=y
CONFIG_NOP_TRACER=y
CONFIG_HAVE_FUNCTION_TRACER=y
CONFIG_HAVE_FUNCTION_GRAPH_TRACER=y
CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST=y
CONFIG_HAVE_DYNAMIC_FTRACE=y
CONFIG_HAVE_FTRACE_MCOUNT_RECORD=y
CONFIG_HAVE_HW_BRANCH_TRACER=y
CONFIG_TRACER_MAX_TRACE=y
CONFIG_FUNCTION_TRACER=y
CONFIG_FUNCTION_GRAPH_TRACER=y
CONFIG_IRQSOFF_TRACER=y
CONFIG_SYSPROF_TRACER=y
CONFIG_SCHED_TRACER=y
CONFIG_CONTEXT_SWITCH_TRACER=y
# CONFIG_BOOT_TRACER is not set
# CONFIG_TRACE_BRANCH_PROFILING is not set
CONFIG_POWER_TRACER=y
CONFIG_STACK_TRACER=y
CONFIG_HW_BRANCH_TRACER=y
CONFIG_DYNAMIC_FTRACE=y
CONFIG_FTRACE_MCOUNT_RECORD=y
# CONFIG_FTRACE_STARTUP_TEST is not set
# CONFIG_MMIOTRACE is not set
# CONFIG_KVM_TRACE is not set


Then on your booted system, do:

echo sched_switch > /sys/kernel/debug/tracing/current_tracer
echo 1 > /sys/kernel/debug/tracing/tracing_enabled
$run_oltp && echo 0 > /sys/kernel/debug/tracing/tracing_enabled

(where $run_oltp is your suite)

Then, email the contents of /sys/kernel/debug/tracing/trace to me

-Greg