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[PATCH -tip 0/5] kprobes: batch (un)optimization support
- From: Masami Hiramatsu <mhiramat at redhat dot com>
- To: Ingo Molnar <mingo at elte dot hu>, lkml<linux-kernel at vger dot kernel dot org>
- Cc: Ananth N Mavinakayanahalli <ananth at in dot ibm dot com>, Ingo Molnar <mingo at elte dot hu>, Jim Keniston <jkenisto at us dot ibm dot com>, Jason Baron <jbaron at redhat dot com>, Mathieu Desnoyers <mathieu dot desnoyers at efficios dot com>, systemtap<systemtap at sources dot redhat dot com>, DLE<dle-develop at lists dot sourceforge dot net>
- Date: Mon, 10 May 2010 13:53:13 -0400
- Subject: [PATCH -tip 0/5] kprobes: batch (un)optimization support
Hi,
Since current kprobes jump optimization calls stop_machine() for each
probe, it will almost freeze machine when registering a lot of probes
(~1000) at once.
For avoiding this issue, this patch series enhances kprobes and
text_poke.
- Introduces text_poke_smp_batch() which modifies multiple codes
with one stop_machine().
- Limits how many probes can be optimized at once.
- Introduce delayed unoptimization for batch processing.
text_poke_smp_batch() also helps Jason's Jump label to reduce
its overhead coming from text_poke_smp().
Currently, this patch allocates working memory static, however,
it is possible to allocate dynamically, because its not in
a critical section. it will be done by the next step, or next version.
Thank you,
---
Masami Hiramatsu (5):
kprobes: Support delayed unoptimization
kprobes/x86: Use text_poke_smp_batch
x86: Introduce text_poke_smp_batch() for batch-code modifying
kprobes: Limit maximum number of optimization at once
[CLEANUP] kprobes: Remove redundant text_mutex lock in optimize
arch/x86/include/asm/alternative.h | 7 +
arch/x86/include/asm/kprobes.h | 4
arch/x86/kernel/alternative.c | 49 +++-
arch/x86/kernel/kprobes.c | 78 ++++++
include/linux/kprobes.h | 4
kernel/kprobes.c | 437 ++++++++++++++++++++++++------------
6 files changed, 416 insertions(+), 163 deletions(-)
--
Masami Hiramatsu
e-mail: mhiramat@redhat.com