[PATCH -tip 0/5] kprobes: batch (un)optimization support

[Masami Hiramatsu <mhiramat@redhat.com>]

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