On 16.10.19 г. 9:39 ч., Qu Wenruo wrote: > [BUG] > For btrfs related events, there is a field for fsid, but perf never > parse it correctly. > > # perf trace -e btrfS:qgroup_meta_convert xfs_io -f -c "pwrite 0 4k" \ > /mnt/btrfs/file1 > 0.000 xfs_io/77915 btrfs:qgroup_meta_reserve:(nil)U: refroot=5(FS_TREE) type=0x0 diff=2 > ^^^^^^ Not a correct UUID > ... > > [CAUSE] > The pretty_print() function doesn't handle the %pU format correctly. > In fact it doesn't handle %pU as uuid at all. > > [FIX] > Add a new functiono, print_uuid_arg(), to handle %pU correctly. > > Now perf trace can at least print fsid correctly: > 0.000 xfs_io/79619 btrfs:qgroup_meta_reserve:23ad1511-dd83-47d4-a79c-e96625a15a6e refroot=5(FS_TREE) type=0x0 diff=2 > > Signed-off-by: Qu Wenruo <wqu@xxxxxxxx> > --- > Please note in above case, the @type and @diff are not properly showed. > That's another problem, will be addressed in later patches. > --- > tools/lib/traceevent/event-parse.c | 38 ++++++++++++++++++++++++++++++ > 1 file changed, 38 insertions(+) > > diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c > index d948475585ce..4f730ed527b0 100644 > --- a/tools/lib/traceevent/event-parse.c > +++ b/tools/lib/traceevent/event-parse.c > @@ -18,6 +18,7 @@ > #include <errno.h> > #include <stdint.h> > #include <limits.h> > +#include <linux/uuid.h> > #include <linux/time64.h> > > #include <netinet/in.h> > @@ -4508,6 +4509,33 @@ get_bprint_format(void *data, int size __maybe_unused, > return format; > } > > +static void print_uuid_arg(struct trace_seq *s, void *data, int size, > + struct tep_event *event, struct tep_print_arg *arg) > +{ > + const char *fmt; > + unsigned char *buf; > + > + fmt = "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x"; > + if (arg->type != TEP_PRINT_FIELD) { > + trace_seq_printf(s, "ARG TYPE NOT FIELID but %d", arg->type); > + return; > + } > + > + if (!arg->field.field) { > + arg->field.field = tep_find_any_field(event, arg->field.name); > + if (!arg->field.field) { > + do_warning("%s: field %s not found", > + __func__, arg->field.name); > + return; > + } > + } > + buf = data + arg->field.field->offset; > + > + trace_seq_printf(s, fmt, buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], > + buf[6], buf[7], buf[8], buf[9], buf[10], buf[11], buf[12], > + buf[13], buf[14], buf[15]); > +} > + > static void print_mac_arg(struct trace_seq *s, int mac, void *data, int size, > struct tep_event *event, struct tep_print_arg *arg) > { > @@ -5074,6 +5102,16 @@ static void pretty_print(struct trace_seq *s, void *data, int size, struct tep_e > arg = arg->next; > break; > } > + } else if (*ptr == 'U') { > + /* Those finetunings are ignored for now */ I think this comment is cryptic. What do you mean by "finetunings"? > + if (isalpha(ptr[1])) > + ptr += 2; > + else > + ptr++; > + > + print_uuid_arg(s, data, size, event, arg); > + arg = arg->next; > + break; > } > > /* fall through */ >