Re: [PATCH v2 1/3] tracing: Deference pointers without RCU checks

2016-08-28 Thread Masami Hiramatsu
Hi Binoy, On Fri, 26 Aug 2016 10:56:12 +0530 Binoy Jayan wrote: > On 26 August 2016 at 07:19, Masami Hiramatsu wrote: > > On Wed, 24 Aug 2016 16:47:28 +0530 > >> "__local_bh_enable() tests if this is the last SOFTIRQ_OFFSET, if so it > >> tells

Re: [PATCH v2 1/3] tracing: Deference pointers without RCU checks

2016-08-28 Thread Masami Hiramatsu
Hi Binoy, On Fri, 26 Aug 2016 10:56:12 +0530 Binoy Jayan wrote: > On 26 August 2016 at 07:19, Masami Hiramatsu wrote: > > On Wed, 24 Aug 2016 16:47:28 +0530 > >> "__local_bh_enable() tests if this is the last SOFTIRQ_OFFSET, if so it > >> tells lockdep softirqs are enabled with

Re: [PATCH v2 1/3] tracing: Deference pointers without RCU checks

2016-08-25 Thread Binoy Jayan
On 26 August 2016 at 07:19, Masami Hiramatsu wrote: > On Wed, 24 Aug 2016 16:47:28 +0530 >> "__local_bh_enable() tests if this is the last SOFTIRQ_OFFSET, if so it >> tells lockdep softirqs are enabled with trace_softirqs_on() after that >> we go an actually modify the

Re: [PATCH v2 1/3] tracing: Deference pointers without RCU checks

2016-08-25 Thread Binoy Jayan
On 26 August 2016 at 07:19, Masami Hiramatsu wrote: > On Wed, 24 Aug 2016 16:47:28 +0530 >> "__local_bh_enable() tests if this is the last SOFTIRQ_OFFSET, if so it >> tells lockdep softirqs are enabled with trace_softirqs_on() after that >> we go an actually modify the preempt_count with

Re: [PATCH v2 1/3] tracing: Deference pointers without RCU checks

2016-08-25 Thread Masami Hiramatsu
On Wed, 24 Aug 2016 16:47:28 +0530 Binoy Jayan wrote: > From: Daniel Wagner > > The tracepoint can't be used in code section where we are in the > middle of a state transition. > > For example if we place a tracepoint inside

Re: [PATCH v2 1/3] tracing: Deference pointers without RCU checks

2016-08-25 Thread Masami Hiramatsu
On Wed, 24 Aug 2016 16:47:28 +0530 Binoy Jayan wrote: > From: Daniel Wagner > > The tracepoint can't be used in code section where we are in the > middle of a state transition. > > For example if we place a tracepoint inside start/stop_critical_section(), > lockdep complains with > > [

[PATCH v2 1/3] tracing: Deference pointers without RCU checks

2016-08-24 Thread Binoy Jayan
From: Daniel Wagner The tracepoint can't be used in code section where we are in the middle of a state transition. For example if we place a tracepoint inside start/stop_critical_section(), lockdep complains with [0.035589] WARNING: CPU: 0 PID: 3 at

[PATCH v2 1/3] tracing: Deference pointers without RCU checks

2016-08-24 Thread Binoy Jayan
From: Daniel Wagner The tracepoint can't be used in code section where we are in the middle of a state transition. For example if we place a tracepoint inside start/stop_critical_section(), lockdep complains with [0.035589] WARNING: CPU: 0 PID: 3 at kernel/locking/lockdep.c:3560 \