* [PATCH] ftrace: kill global_start_up @ 2014-07-20 15:18 Oleg Nesterov 2014-07-21 13:47 ` Steven Rostedt 0 siblings, 1 reply; 6+ messages in thread From: Oleg Nesterov @ 2014-07-20 15:18 UTC (permalink / raw) To: Steven Rostedt; +Cc: linux-kernel global_start_up is read-only and always zero. It seems that 4104d326 "ftrace: Remove global function list and call function directly" simply forgot to remove this no longer used variable. Signed-off-by: Oleg Nesterov <oleg@redhat.com> --- kernel/trace/ftrace.c | 4 +--- 1 files changed, 1 insertions(+), 3 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 5b372e3..4586f8d 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2053,7 +2053,6 @@ static void ftrace_run_update_code(int command) static ftrace_func_t saved_ftrace_func; static int ftrace_start_up; -static int global_start_up; static void control_ops_free(struct ftrace_ops *ops) { @@ -2117,8 +2116,7 @@ static int ftrace_shutdown(struct ftrace_ops *ops, int command) ftrace_hash_rec_disable(ops, 1); - if (!global_start_up) - ops->flags &= ~FTRACE_OPS_FL_ENABLED; + ops->flags &= ~FTRACE_OPS_FL_ENABLED; command |= FTRACE_UPDATE_CALLS; -- 1.5.5.1 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] ftrace: kill global_start_up 2014-07-20 15:18 [PATCH] ftrace: kill global_start_up Oleg Nesterov @ 2014-07-21 13:47 ` Steven Rostedt 2014-07-21 13:50 ` Steven Rostedt 0 siblings, 1 reply; 6+ messages in thread From: Steven Rostedt @ 2014-07-21 13:47 UTC (permalink / raw) To: Oleg Nesterov; +Cc: linux-kernel On Sun, 20 Jul 2014 17:18:14 +0200 Oleg Nesterov <oleg@redhat.com> wrote: > global_start_up is read-only and always zero. It seems that 4104d326 > "ftrace: Remove global function list and call function directly" simply > forgot to remove this no longer used variable. > Sure, just after I got done testing my entire 3.17 queue and posted it for linux-next, you decide to send me yet another fix! ;-) Thanks, applied. I'll wait and see what other fixes you send me before I run my 10 hour tests. -- Steve > Signed-off-by: Oleg Nesterov <oleg@redhat.com> > --- > kernel/trace/ftrace.c | 4 +--- > 1 files changed, 1 insertions(+), 3 deletions(-) > > diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c > index 5b372e3..4586f8d 100644 > --- a/kernel/trace/ftrace.c > +++ b/kernel/trace/ftrace.c > @@ -2053,7 +2053,6 @@ static void ftrace_run_update_code(int command) > > static ftrace_func_t saved_ftrace_func; > static int ftrace_start_up; > -static int global_start_up; > > static void control_ops_free(struct ftrace_ops *ops) > { > @@ -2117,8 +2116,7 @@ static int ftrace_shutdown(struct ftrace_ops *ops, int command) > > ftrace_hash_rec_disable(ops, 1); > > - if (!global_start_up) > - ops->flags &= ~FTRACE_OPS_FL_ENABLED; > + ops->flags &= ~FTRACE_OPS_FL_ENABLED; > > command |= FTRACE_UPDATE_CALLS; > ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] ftrace: kill global_start_up 2014-07-21 13:47 ` Steven Rostedt @ 2014-07-21 13:50 ` Steven Rostedt 2014-07-23 18:29 ` Oleg Nesterov 0 siblings, 1 reply; 6+ messages in thread From: Steven Rostedt @ 2014-07-21 13:50 UTC (permalink / raw) To: Oleg Nesterov; +Cc: linux-kernel On Mon, 21 Jul 2014 09:47:06 -0400 Steven Rostedt <rostedt@goodmis.org> wrote: > On Sun, 20 Jul 2014 17:18:14 +0200 > Oleg Nesterov <oleg@redhat.com> wrote: > > > global_start_up is read-only and always zero. It seems that 4104d326 > > "ftrace: Remove global function list and call function directly" simply > > forgot to remove this no longer used variable. > > > > Sure, just after I got done testing my entire 3.17 queue and posted it > for linux-next, you decide to send me yet another fix! ;-) > > Thanks, applied. > > I'll wait and see what other fixes you send me before I run my 10 hour > tests. > Nevermind, seems that Namhyung Kim beat you to it (and it's already in my for-next branch). http://lkml.kernel.org/r/1402584972-17824-1-git-send-email-namhyung@kernel.org -- Steve ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] ftrace: kill global_start_up 2014-07-21 13:50 ` Steven Rostedt @ 2014-07-23 18:29 ` Oleg Nesterov 2014-07-23 18:53 ` Steven Rostedt 0 siblings, 1 reply; 6+ messages in thread From: Oleg Nesterov @ 2014-07-23 18:29 UTC (permalink / raw) To: Steven Rostedt, Namhyung Kim; +Cc: linux-kernel On 07/21, Steven Rostedt wrote: > > On Mon, 21 Jul 2014 09:47:06 -0400 > Steven Rostedt <rostedt@goodmis.org> wrote: > > > On Sun, 20 Jul 2014 17:18:14 +0200 > > Oleg Nesterov <oleg@redhat.com> wrote: > > > > > global_start_up is read-only and always zero. It seems that 4104d326 > > > "ftrace: Remove global function list and call function directly" simply > > > forgot to remove this no longer used variable. > > > > > > > Sure, just after I got done testing my entire 3.17 queue and posted it > > for linux-next, you decide to send me yet another fix! ;-) > > > > Thanks, applied. > > > > I'll wait and see what other fixes you send me before I run my 10 hour > > tests. > > > > Nevermind, seems that Namhyung Kim beat you to it (and it's already in > my for-next branch). > > http://lkml.kernel.org/r/1402584972-17824-1-git-send-email-namhyung@kernel.org Thanks for your report Steven, I updated my ~/people-i-hate file. This motivated me to try to find something else unused. And it seems that almost all code in kernel/trace/trace_sched_switch.c is dead? Hmm, and probably even event_context_switch... I'll recheck and send the patch. But is there any documentation about /sys/kernel/debug/tracing/events/ftrace/* files ? OK, as I just figured out ftrace/function is special, it is visible to perf and thus "record ftrace:function" should work. But what a user can do with other files? You obviously can't enable, say, ftrace/bputs, if I understand correctly this is for trace_puts(). Confused... Oleg. ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] ftrace: kill global_start_up 2014-07-23 18:29 ` Oleg Nesterov @ 2014-07-23 18:53 ` Steven Rostedt 2014-07-23 19:51 ` Oleg Nesterov 0 siblings, 1 reply; 6+ messages in thread From: Steven Rostedt @ 2014-07-23 18:53 UTC (permalink / raw) To: Oleg Nesterov; +Cc: Namhyung Kim, linux-kernel On Wed, 23 Jul 2014 20:29:11 +0200 Oleg Nesterov <oleg@redhat.com> wrote: > > Nevermind, seems that Namhyung Kim beat you to it (and it's already in > > my for-next branch). > > > > http://lkml.kernel.org/r/1402584972-17824-1-git-send-email-namhyung@kernel.org > > Thanks for your report Steven, I updated my ~/people-i-hate file. Is that for me or Namhyung? Silly question, it has to be for Namhyung, as I'm sure I'm one of the first people already in that list. > > > This motivated me to try to find something else unused. And it seems that > almost all code in kernel/trace/trace_sched_switch.c is dead? Hmm, and sched_switch? Move along, nothing to see here... OK, there was a time we had a bunch of "tracers" (those things in the available_tracers file). And since events and perf came along, there was a push to remove them all. We never got rid of function, function_graph, mmiotrace and the latency tracers as they are quite different from events (function is close, but they need special care). One of the casualties to that tracer purge was the sched_switch tracer. But it wasn't such a simple removal, as that code was in charge of the trace_find_cmdline() logic. Well, to get people away from using it, we removed it from the "available_tracers" file, but kept most of the code as clean up for another day. As with most things on a TODO list, they get pushed down to the bottom, crushed by the many things above it, and finally swept under the rug until some nosy developer decides to take a peek under that carpet and point to the maintainer of said code with his white glove on and the smudge at the end of his finger and say "WHAT'S THIS!". Well, here's a broom and dustpan, have at it! > probably even event_context_switch... I'll recheck and send the patch. > > But is there any documentation about /sys/kernel/debug/tracing/events/ftrace/* > files ? No, they are mostly internal, and only there for the format files for things like trace-cmd and perf to be able to parse it. > > OK, as I just figured out ftrace/function is special, it is visible to > perf and thus "record ftrace:function" should work. > > But what a user can do with other files? You obviously can't enable, say, > ftrace/bputs, if I understand correctly this is for trace_puts(). > Yeah, as trace_printk() can turn into a trace_puts() we still want those to be read by trace-cmd. To do that, the formats for those files are exported. See kernel/trace/trace_export.c and trace_entries.h > Confused... Aren't we all? -- Steve ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] ftrace: kill global_start_up 2014-07-23 18:53 ` Steven Rostedt @ 2014-07-23 19:51 ` Oleg Nesterov 0 siblings, 0 replies; 6+ messages in thread From: Oleg Nesterov @ 2014-07-23 19:51 UTC (permalink / raw) To: Steven Rostedt; +Cc: Namhyung Kim, linux-kernel On 07/23, Steven Rostedt wrote: > > On Wed, 23 Jul 2014 20:29:11 +0200 > Oleg Nesterov <oleg@redhat.com> wrote: > > > Thanks for your report Steven, I updated my ~/people-i-hate file. > > Is that for me or Namhyung? Silly question, it has to be for Namhyung, > as I'm sure I'm one of the first people already in that list. Sure, you are already listed more than once. > > probably even event_context_switch... I'll recheck and send the patch. This one is used by probe_wakeup_sched_switch(), so we can't simply remove it. > > But what a user can do with other files? You obviously can't enable, say, > > ftrace/bputs, if I understand correctly this is for trace_puts(). > > > > Yeah, as trace_printk() can turn into a trace_puts() we still want > those to be read by trace-cmd. To do that, the formats for those files > are exported. Ah, indeed, thanks. > See kernel/trace/trace_export.c and trace_entries.h Yeeees, I already found them. And this wasn't easy ;) Thanks, Oleg. ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2014-07-23 19:53 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2014-07-20 15:18 [PATCH] ftrace: kill global_start_up Oleg Nesterov 2014-07-21 13:47 ` Steven Rostedt 2014-07-21 13:50 ` Steven Rostedt 2014-07-23 18:29 ` Oleg Nesterov 2014-07-23 18:53 ` Steven Rostedt 2014-07-23 19:51 ` Oleg Nesterov
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