Re: [RFC PATCH tip 4/5] use BPF in tracing filters

2013-12-09 Thread Masami Hiramatsu
(2013/12/09 3:22), Frank Ch. Eigler wrote: > > masami.hiramatsu.pt wrote: > >> [...] >> Anyway, as far as I can see, there looks be two different models of >> tracing in our mind. >> >> A) Fixed event based tracing: In this model, there are several fixed >> "events" which well defined with fixed

Re: [RFC PATCH tip 4/5] use BPF in tracing filters

2013-12-08 Thread Frank Ch. Eigler
masami.hiramatsu.pt wrote: > [...] > Anyway, as far as I can see, there looks be two different models of > tracing in our mind. > > A) Fixed event based tracing: In this model, there are several fixed > "events" which well defined with fixed arguments. tracer handles these > events and only use l

Re: [RFC PATCH tip 4/5] use BPF in tracing filters

2013-12-06 Thread Masami Hiramatsu
(2013/12/06 19:05), Jovi Zhangwei wrote: > On Fri, Dec 6, 2013 at 4:43 PM, Masami Hiramatsu > wrote: >> (2013/12/05 14:11), Alexei Starovoitov wrote: >>> On Wed, Dec 4, 2013 at 4:05 PM, Masami Hiramatsu >>> wrote: (2013/12/04 10:11), Steven Rostedt wrote: > On Wed, 04 Dec 2013 09:48:44 +

Re: [RFC PATCH tip 4/5] use BPF in tracing filters

2013-12-06 Thread Jovi Zhangwei
On Fri, Dec 6, 2013 at 4:43 PM, Masami Hiramatsu wrote: > (2013/12/05 14:11), Alexei Starovoitov wrote: >> On Wed, Dec 4, 2013 at 4:05 PM, Masami Hiramatsu >> wrote: >>> (2013/12/04 10:11), Steven Rostedt wrote: On Wed, 04 Dec 2013 09:48:44 +0900 Masami Hiramatsu wrote: > fetc

Re: [RFC PATCH tip 4/5] use BPF in tracing filters

2013-12-06 Thread Masami Hiramatsu
(2013/12/05 14:11), Alexei Starovoitov wrote: > On Wed, Dec 4, 2013 at 4:05 PM, Masami Hiramatsu > wrote: >> (2013/12/04 10:11), Steven Rostedt wrote: >>> On Wed, 04 Dec 2013 09:48:44 +0900 >>> Masami Hiramatsu wrote: >>> fetch functions and actions. In that case, we can continue to use

Re: [RFC PATCH tip 4/5] use BPF in tracing filters

2013-12-04 Thread Alexei Starovoitov
On Wed, Dec 4, 2013 at 4:05 PM, Masami Hiramatsu wrote: > (2013/12/04 10:11), Steven Rostedt wrote: >> On Wed, 04 Dec 2013 09:48:44 +0900 >> Masami Hiramatsu wrote: >> >>> fetch functions and actions. In that case, we can continue >>> to use current interface but much faster to trace. >>> Also, w

Re: [RFC PATCH tip 4/5] use BPF in tracing filters

2013-12-04 Thread Masami Hiramatsu
(2013/12/04 10:11), Steven Rostedt wrote: > On Wed, 04 Dec 2013 09:48:44 +0900 > Masami Hiramatsu wrote: > >> (2013/12/03 13:28), Alexei Starovoitov wrote: >>> Such filters can be written in C and allow safe read-only access to >>> any kernel data structure. >>> Like systemtap but with safety gua

Re: [RFC PATCH tip 4/5] use BPF in tracing filters

2013-12-03 Thread Steven Rostedt
On Wed, 04 Dec 2013 09:48:44 +0900 Masami Hiramatsu wrote: > (2013/12/03 13:28), Alexei Starovoitov wrote: > > Such filters can be written in C and allow safe read-only access to > > any kernel data structure. > > Like systemtap but with safety guaranteed by kernel. > > > > The user can do: > >

Re: [RFC PATCH tip 4/5] use BPF in tracing filters

2013-12-03 Thread Masami Hiramatsu
(2013/12/03 13:28), Alexei Starovoitov wrote: > Such filters can be written in C and allow safe read-only access to > any kernel data structure. > Like systemtap but with safety guaranteed by kernel. > > The user can do: > cat bpf_program > /sys/kernel/debug/tracing/.../filter > if tracing event i