On Tue, 09 Aug 2011 08:53:15 -0400, Steven Rostedt <srostedt@xxxxxxxxxx> wrote:
> On Tue, 2011-08-09 at 18:12 +0530, Aneesh Kumar K.V wrote:
>
> > +#define P9_PROTO_DUMP_SZ (16 * 3 + 2 + 16 + 1)
>
> Wow, you're making your event have 67 byte arrays, two of them.
>
> > +TRACE_EVENT(9p_protocol_dump,
> > + TP_PROTO(struct p9_client *clnt, struct p9_fcall *pdu),
> > +
> > + TP_ARGS(clnt, pdu),
> > +
> > + TP_STRUCT__entry(
> > + __field( __u64, clnt )
> > + __field( __u8, type )
> > + __field( __u16, tag )
> > + __array( unsigned char, line1, P9_PROTO_DUMP_SZ )
> > + __array( unsigned char, line2, P9_PROTO_DUMP_SZ )
> > + ),
>
> Wouldn't it be better to put this as two unsigned char arrays of 16
> bytes?
>
> > +
> > + TP_fast_assign(
> > + const u8 *ptr = pdu->sdata;
> > + __entry->clnt = (__u64)clnt;
> > + __entry->type = pdu->id;
> > + __entry->tag = pdu->tag;
> > + hex_dump_to_buffer(ptr, 16, 16,
> > + 1, __entry->line1, P9_PROTO_DUMP_SZ, true);
> > + hex_dump_to_buffer(ptr + 16, 16, 16,
> > + 1, __entry->line2, P9_PROTO_DUMP_SZ, true);
> > + ),
> > +
> > + TP_printk("clnt %lu %s(tag = %d)\n%.8x: %s\n%.8x: %s\n",
> > + (long)__entry->clnt, show_9p_op(__entry->type),
> > + __entry->tag, 0, __entry->line1, 16 , __entry->line2)
>
> Yeah, you would need to make the above ugly to print out the array, but
> it's not that hard. And you will be saving 102 bytes per event in the
> ring buffer, which is very expensive real-estate. Not to mention the
> time it takes to copy all that.
>
Any suggestion on how to get this pretty printing of the hex data. I can
update print_hex_dump_bytes to dump the hex data to a buffer. But not
sure where i can free the buffer after using that in TP_printk.
-aneesh
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
