Rabin, This looks fine to me -- Qiao, can you please ACK this patch? Thanks,     Dave ----- Original Message ----- > max_buffer is optional in the kernel (depends on the > CONFIG_TRACE_MAX_TRACE option).  Don't fail if it isn't available.

> --- >   extensions/trace.c |   14 +++++++++++++- >   1 file changed, 13 insertions(+), 1 deletion(-) > > diff --git a/extensions/trace.c b/extensions/trace.c > index 9f81568..c269f4c 100644 > --- a/extensions/trace.c > +++ b/extensions/trace.c > @@ -34,6 +34,10 @@ static int encapsulated_current_trace; >    * trace_buffer is supported >    */ >   static int trace_buffer_available; > +/* > + * max_buffer is supported > + */ > +static int max_buffer_available; > >   #define koffset(struct, member) struct##_##member##_offset > > @@ -163,8 +167,10 @@ static int init_offsets(void) > >   if (trace_buffer_available) { >   init_offset(trace_array, trace_buffer); > - init_offset(trace_array, max_buffer); >   init_offset(trace_buffer, buffer); > + > + if (max_buffer_available) > + init_offset(trace_array, max_buffer); >   } else { >   init_offset(trace_array, buffer); >   } > @@ -448,6 +454,9 @@ out_fail: >   static int ftrace_int_max_tr_trace(void) >   { >   if (trace_buffer_available) { > + if (!max_buffer_available) > + return 0; > + >   global_max_buffer = global_trace + koffset(trace_array, max_buffer); >   read_value(max_tr_ring_buffer, global_max_buffer, trace_buffer, buffer); >   } else { > @@ -528,6 +537,9 @@ static int ftrace_init(void) > >   if (MEMBER_EXISTS("trace_array", "trace_buffer")) { >   trace_buffer_available = 1; > + > + if (MEMBER_EXISTS("trace_array", "max_buffer")) > + max_buffer_available = 1; >   } else { >   sym_max_tr_trace = symbol_search("max_tr"); >   if (sym_max_tr_trace == NULL) > -- > 1.7.10.4 > > -- > Crash-utility mailing list > Crash-utility(a)redhat.com > https://www.redhat.com/mailman/listinfo/crash-utility > .