Message ID | 20191017022800.31866-1-wqu@suse.com (mailing list archive) |
---|---|
State | Superseded |
Headers | show |
Series | [v2] tools/lib/traceevent, perf tools: Handle %pU format correctly | expand |
On Thu, Oct 17, 2019 at 10:28:00AM +0800, 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 function, 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@suse.com> > --- > Changelog: > v2: > - Use more comment explaining the finetunings we skipped for %pU* > - Use more elegant way to output uuid string > --- > tools/lib/traceevent/event-parse.c | 56 ++++++++++++++++++++++++++++++ > 1 file changed, 56 insertions(+) > > diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c > index d948475585ce..3c9473f46efe 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 +4509,45 @@ 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) > +{ > + unsigned char *buf; > + int i; > + > + 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; > + } > + } > + if (arg->field.field->size < 16) { > + trace_seq_printf(s, "INVALID UUID: size have %u expect 16", > + arg->field.field->size); > + return; > + } So if there's an interest for very compact printing loop, something like this produces the same output: for (i = 0; i < 8; i++) { printf("%02X", buf[i]); printf("%02X", buf[i]); if (1 <= i && i <= 4) putchar('-'); } "23ad 1511 - dd83 - 47d4 - a79c - e966 25a1 5a6e" 0 1 2 3 4 5 6 7 IOW, split into pairs and print dash after a few of them.
On Thu, Oct 17, 2019 at 01:52:09PM +0200, David Sterba wrote: > On Thu, Oct 17, 2019 at 10:28:00AM +0800, 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 function, 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@suse.com> > > --- > > Changelog: > > v2: > > - Use more comment explaining the finetunings we skipped for %pU* > > - Use more elegant way to output uuid string > > --- > > tools/lib/traceevent/event-parse.c | 56 ++++++++++++++++++++++++++++++ > > 1 file changed, 56 insertions(+) > > > > diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c > > index d948475585ce..3c9473f46efe 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 +4509,45 @@ 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) > > +{ > > + unsigned char *buf; > > + int i; > > + > > + 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; > > + } > > + } > > + if (arg->field.field->size < 16) { > > + trace_seq_printf(s, "INVALID UUID: size have %u expect 16", > > + arg->field.field->size); > > + return; > > + } > > So if there's an interest for very compact printing loop, something like > this produces the same output: > > for (i = 0; i < 8; i++) { > printf("%02X", buf[i]); > printf("%02X", buf[i]); Ok, test-before-post failure, this should be printf("%02X", buf[2 * i]); printf("%02X", buf[2 * i + 1]); > if (1 <= i && i <= 4) > putchar('-'); > }
On Thu, 17 Oct 2019 13:54:23 +0200 David Sterba <dsterba@suse.cz> wrote: > > So if there's an interest for very compact printing loop, something like > > this produces the same output: > > > > for (i = 0; i < 8; i++) { > > printf("%02X", buf[i]); > > printf("%02X", buf[i]); > > Ok, test-before-post failure, this should be > > printf("%02X", buf[2 * i]); > printf("%02X", buf[2 * i + 1]); > > > if (1 <= i && i <= 4) > > putchar('-'); > > } I'm fine if you want to post a v3 with this update. -- Steve
diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c index d948475585ce..3c9473f46efe 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 +4509,45 @@ 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) +{ + unsigned char *buf; + int i; + + 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; + } + } + if (arg->field.field->size < 16) { + trace_seq_printf(s, "INVALID UUID: size have %u expect 16", + arg->field.field->size); + return; + } + buf = data + arg->field.field->offset; + /* first segment, %02x *4 */ + for (i = 0; i < 4; i++, buf++) + trace_seq_printf(s, "%02x", *buf); + + /* 2nd, 3rd, 4th segment, each segment is "-%02x%02x" */ + for (i = 0; i < 3; i++, buf += 2) + trace_seq_printf(s, "-%02x%02x", buf[i * 2], buf[i * 2 + 1]); + + /* Final segment, '-' and '%02x' *6 */ + trace_seq_putc(s, '-'); + for (i = 0; i < 6; i++, buf++) + trace_seq_printf(s, "%02x", *buf); +} + 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 +5114,22 @@ static void pretty_print(struct trace_seq *s, void *data, int size, struct tep_e arg = arg->next; break; } + } else if (*ptr == 'U') { + /* + * %pU has several finetunings variants + * like %pUb and %pUL. + * Here we ignore them, default to + * byte-order no endian, lower case + * letters. + */ + if (isalpha(ptr[1])) + ptr += 2; + else + ptr++; + + print_uuid_arg(s, data, size, event, arg); + arg = arg->next; + break; } /* fall through */
[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 function, 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@suse.com> --- Changelog: v2: - Use more comment explaining the finetunings we skipped for %pU* - Use more elegant way to output uuid string --- tools/lib/traceevent/event-parse.c | 56 ++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+)