Re: [PATCH -tip v3 7/7] kprobes: Use synchronize_rcu_tasks() for optprobe with CONFIG_PREEMPT

On Tue, 3 Oct 2017 19:57:22 -0400 Steven Rostedt wrote: > > Sorry for the late reply. Coming back from Kernel Recipes, I fell way > behind in email. > > On Fri, 29 Sep 2017 00:29:38 -0700 > Masami Hiramatsu wrote: > > > > > +* are done.

Re: [PATCH -tip v3 7/7] kprobes: Use synchronize_rcu_tasks() for optprobe with CONFIG_PREEMPT

On Tue, 3 Oct 2017 19:57:22 -0400 Steven Rostedt wrote: > > Sorry for the late reply. Coming back from Kernel Recipes, I fell way > behind in email. > > On Fri, 29 Sep 2017 00:29:38 -0700 > Masami Hiramatsu wrote: > > > > > +* are done. Because optprobe may modify multiple

Re: [PATCH -tip v3 7/7] kprobes: Use synchronize_rcu_tasks() for optprobe with CONFIG_PREEMPT

Sorry for the late reply. Coming back from Kernel Recipes, I fell way behind in email. On Fri, 29 Sep 2017 00:29:38 -0700 Masami Hiramatsu wrote: > > > + * are done. Because optprobe may modify multiple instructions, > > > + * there is a chance that the Nth instruction

Re: [PATCH -tip v3 7/7] kprobes: Use synchronize_rcu_tasks() for optprobe with CONFIG_PREEMPT

Sorry for the late reply. Coming back from Kernel Recipes, I fell way behind in email. On Fri, 29 Sep 2017 00:29:38 -0700 Masami Hiramatsu wrote: > > > + * are done. Because optprobe may modify multiple instructions, > > > + * there is a chance that the Nth instruction is interrupted. In

Re: [PATCH -tip v3 7/7] kprobes: Use synchronize_rcu_tasks() for optprobe with CONFIG_PREEMPT

On Fri, 29 Sep 2017 19:45:28 +0200 Ingo Molnar wrote: > > * Masami Hiramatsu wrote: > > > On Fri, 29 Sep 2017 09:37:55 +0200 > > Ingo Molnar wrote: > > > > > > > > * Masami Hiramatsu wrote: > > > > > > > On

Re: [PATCH -tip v3 7/7] kprobes: Use synchronize_rcu_tasks() for optprobe with CONFIG_PREEMPT

On Fri, 29 Sep 2017 19:45:28 +0200 Ingo Molnar wrote: > > * Masami Hiramatsu wrote: > > > On Fri, 29 Sep 2017 09:37:55 +0200 > > Ingo Molnar wrote: > > > > > > > > * Masami Hiramatsu wrote: > > > > > > > On Thu, 28 Sep 2017 09:22:20 +0200 > > > > Ingo Molnar wrote: > > > > > > > > > >

Re: [PATCH -tip v3 7/7] kprobes: Use synchronize_rcu_tasks() for optprobe with CONFIG_PREEMPT

* Masami Hiramatsu wrote: > On Fri, 29 Sep 2017 09:37:55 +0200 > Ingo Molnar wrote: > > > > > * Masami Hiramatsu wrote: > > > > > On Thu, 28 Sep 2017 09:22:20 +0200 > > > Ingo Molnar wrote: > > > > > > > > > >

Re: [PATCH -tip v3 7/7] kprobes: Use synchronize_rcu_tasks() for optprobe with CONFIG_PREEMPT

* Masami Hiramatsu wrote: > On Fri, 29 Sep 2017 09:37:55 +0200 > Ingo Molnar wrote: > > > > > * Masami Hiramatsu wrote: > > > > > On Thu, 28 Sep 2017 09:22:20 +0200 > > > Ingo Molnar wrote: > > > > > > > > > > > * Masami Hiramatsu wrote: > > > > > > > > > To enable jump optimized

Re: [PATCH -tip v3 7/7] kprobes: Use synchronize_rcu_tasks() for optprobe with CONFIG_PREEMPT

On Fri, 29 Sep 2017 09:37:55 +0200 Ingo Molnar wrote: > > * Masami Hiramatsu wrote: > > > On Thu, 28 Sep 2017 09:22:20 +0200 > > Ingo Molnar wrote: > > > > > > > > * Masami Hiramatsu wrote: > > > > > > > To

Re: [PATCH -tip v3 7/7] kprobes: Use synchronize_rcu_tasks() for optprobe with CONFIG_PREEMPT

On Fri, 29 Sep 2017 09:37:55 +0200 Ingo Molnar wrote: > > * Masami Hiramatsu wrote: > > > On Thu, 28 Sep 2017 09:22:20 +0200 > > Ingo Molnar wrote: > > > > > > > > * Masami Hiramatsu wrote: > > > > > > > To enable jump optimized probe with CONFIG_PREEMPT, use > > > >

Re: [PATCH -tip v3 7/7] kprobes: Use synchronize_rcu_tasks() for optprobe with CONFIG_PREEMPT

* Masami Hiramatsu wrote: > On Thu, 28 Sep 2017 09:22:20 +0200 > Ingo Molnar wrote: > > > > > * Masami Hiramatsu wrote: > > > > > To enable jump optimized probe with CONFIG_PREEMPT, use > > > synchronize_rcu_tasks() to wait for

Re: [PATCH -tip v3 7/7] kprobes: Use synchronize_rcu_tasks() for optprobe with CONFIG_PREEMPT

* Masami Hiramatsu wrote: > On Thu, 28 Sep 2017 09:22:20 +0200 > Ingo Molnar wrote: > > > > > * Masami Hiramatsu wrote: > > > > > To enable jump optimized probe with CONFIG_PREEMPT, use > > > synchronize_rcu_tasks() to wait for all tasks preempted > > > on trampoline code back on track. >

Re: [PATCH -tip v3 7/7] kprobes: Use synchronize_rcu_tasks() for optprobe with CONFIG_PREEMPT

On Thu, 28 Sep 2017 09:22:20 +0200 Ingo Molnar wrote: > > * Masami Hiramatsu wrote: > > > To enable jump optimized probe with CONFIG_PREEMPT, use > > synchronize_rcu_tasks() to wait for all tasks preempted > > on trampoline code back on track. > > This

Re: [PATCH -tip v3 7/7] kprobes: Use synchronize_rcu_tasks() for optprobe with CONFIG_PREEMPT

On Thu, 28 Sep 2017 09:22:20 +0200 Ingo Molnar wrote: > > * Masami Hiramatsu wrote: > > > To enable jump optimized probe with CONFIG_PREEMPT, use > > synchronize_rcu_tasks() to wait for all tasks preempted > > on trampoline code back on track. > > This sentence does not parse. It's missing a

Re: [PATCH -tip v3 7/7] kprobes: Use synchronize_rcu_tasks() for optprobe with CONFIG_PREEMPT

* Masami Hiramatsu wrote: > To enable jump optimized probe with CONFIG_PREEMPT, use > synchronize_rcu_tasks() to wait for all tasks preempted > on trampoline code back on track. This sentence does not parse. It's missing a verb, but I'm not sure. > Since the jump

Re: [PATCH -tip v3 7/7] kprobes: Use synchronize_rcu_tasks() for optprobe with CONFIG_PREEMPT

* Masami Hiramatsu wrote: > To enable jump optimized probe with CONFIG_PREEMPT, use > synchronize_rcu_tasks() to wait for all tasks preempted > on trampoline code back on track. This sentence does not parse. It's missing a verb, but I'm not sure. > Since the jump optimized kprobes can replace

[PATCH -tip v3 7/7] kprobes: Use synchronize_rcu_tasks() for optprobe with CONFIG_PREEMPT

To enable jump optimized probe with CONFIG_PREEMPT, use synchronize_rcu_tasks() to wait for all tasks preempted on trampoline code back on track. Since the jump optimized kprobes can replace multiple instructions, there can be tasks which are preempted on the 2nd (or 3rd) instructions. If the

[PATCH -tip v3 7/7] kprobes: Use synchronize_rcu_tasks() for optprobe with CONFIG_PREEMPT

To enable jump optimized probe with CONFIG_PREEMPT, use synchronize_rcu_tasks() to wait for all tasks preempted on trampoline code back on track. Since the jump optimized kprobes can replace multiple instructions, there can be tasks which are preempted on the 2nd (or 3rd) instructions. If the