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authorMasami Hiramatsu <mhiramat@redhat.com>2010-02-25 08:34:07 -0500
committerIngo Molnar <mingo@elte.hu>2010-02-25 17:49:24 +0100
commitafd66255b9a48f5851326ddae50e2203fbf71dc9 (patch)
tree32c7a36a8e2c740b989f16b3e2878f8c565d57f8 /arch
parent4610ee1d3638fa05ba8e87ccfa971db8e4033ae7 (diff)
downloadop-kernel-dev-afd66255b9a48f5851326ddae50e2203fbf71dc9.zip
op-kernel-dev-afd66255b9a48f5851326ddae50e2203fbf71dc9.tar.gz
kprobes: Introduce kprobes jump optimization
Introduce kprobes jump optimization arch-independent parts. Kprobes uses breakpoint instruction for interrupting execution flow, on some architectures, it can be replaced by a jump instruction and interruption emulation code. This gains kprobs' performance drastically. To enable this feature, set CONFIG_OPTPROBES=y (default y if the arch supports OPTPROBE). Changes in v9: - Fix a bug to optimize probe when enabling. - Check nearby probes can be optimize/unoptimize when disarming/arming kprobes, instead of registering/unregistering. This will help kprobe-tracer because most of probes on it are usually disabled. Changes in v6: - Cleanup coding style for readability. - Add comments around get/put_online_cpus(). Changes in v5: - Use get_online_cpus()/put_online_cpus() for avoiding text_mutex deadlock. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: systemtap <systemtap@sources.redhat.com> Cc: DLE <dle-develop@lists.sourceforge.net> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Anders Kaseorg <andersk@ksplice.com> Cc: Tim Abbott <tabbott@ksplice.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jason Baron <jbaron@redhat.com> Cc: Mathieu Desnoyers <compudj@krystal.dyndns.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> LKML-Reference: <20100225133407.6725.81992.stgit@localhost6.localdomain6> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch')
-rw-r--r--arch/Kconfig13
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/Kconfig b/arch/Kconfig
index 9d055b4..e0ad3ca 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -57,6 +57,17 @@ config KPROBES
for kernel debugging, non-intrusive instrumentation and testing.
If in doubt, say "N".
+config OPTPROBES
+ bool "Kprobes jump optimization support (EXPERIMENTAL)"
+ default y
+ depends on KPROBES
+ depends on !PREEMPT
+ depends on HAVE_OPTPROBES
+ select KALLSYMS_ALL
+ help
+ This option will allow kprobes to optimize breakpoint to
+ a jump for reducing its overhead.
+
config HAVE_EFFICIENT_UNALIGNED_ACCESS
bool
help
@@ -99,6 +110,8 @@ config HAVE_KPROBES
config HAVE_KRETPROBES
bool
+config HAVE_OPTPROBES
+ bool
#
# An arch should select this if it provides all these things:
#
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