Re: [PATCH RESEND 1/3] tracing/syscalls: Rename variable 'nr' to 'syscall_nr'

[Taeung Song]

On 02/26/2016 02:09 AM, Steven Rostedt wrote:
> On Thu, 25 Feb 2016 12:05:01 -0500
> Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
>
> > On Fri, 26 Feb 2016 01:53:47 +0900
> > Taeung Song <treeze.taeung@xxxxxxxxx> wrote:
> >
> > > The underlying cause of this problem is not because of
> > > the python script. This problem have relevance to tracing/syscalls
> > > as below.
> > >
> > > # cat
> > > /sys/kernel/debug/tracing/events/syscalls/sys_enter_io_getevents/format
> > > name: sys_enter_io_getevents
> > > ID: 739
> > > format:
> > >          field:unsigned short common_type; offset:0;size:2;signed:0;
> > >          field:unsigned char common_flags; offset:2;size:1;signed:0;
> > >          field:unsigned char common_preempt_count; offset:3;size:1;signed:0;
> > >          field:int common_pid;             offset:4;size:4;signed:1;
> > >          field:int nr;                     offset:8;size:4;signed:1;
> > >          field:aio_context_t ctx_id;       offset:16;size:8;signed:0;
> > >          field:long min_nr;                offset:24;size:8;signed:0;
> > >          field:long nr;                    offset:32;size:8;signed:0;
> > >          field:struct io_event * events;   offset:40;size:8;signed:0;
> > >          field:struct timespec * timeout;  offset:48;size:8;signed:0;
> > >
> > > print fmt: "ctx_id: 0x%08lx, min_nr: 0x%08lx, nr: 0x%08lx, events:
> > > 0x%08lx, timeout: 0x%08lx", ((unsigned long)(REC->ctx_id)), ((unsigned
> > > long)(REC->min_nr)), ((unsigned long)(REC->nr)), ((unsigned
> > > long)(REC->events)), ((unsigned long)(REC->timeout))
> > >
> > >
> > > As you see, there are duplicated variable name among fields.
> > > So I renamed the variable name 'nr' to 'syscall_nr' to avoid this
> > > duplication. As you know 'nr' in print_syscall_enter() mean
> > > system call number so, I changed 'nr' to 'syscall_nr'(IMHO).
> >
> > The above should have been in the change log. That makes much more
> > sense.

Sorry, this change log is misinterpretable.
So I'm rewriting change log for this patch.
I will resend it soon.

> I'm a bit nervous about this change though. Because it is an ABI
> change. Hopefully there's no tools that parse the syscall tracepoints
> and expect to find a 'nr' in there.

AFIAIK, I think so but resend this modified patch.

Thanks,
Taeung