From: Kan Liang <[email protected]>
Sometime, especially debugging scaling issue, the function level diff
may be high granularity. The user may want to do deeper diff analysis
for some cache or lock issue. The "symoff" key can let the user sort
differential profile by ips.
Here is an example.
The source code for example_v1.c is as below:
noinline void f3(void)
{
volatile int i;
for (i = 0; i < 10000;) {
if(i%2)
i++;
else
i++;
}
}
noinline void f2(void)
{
volatile int a = 100, b, c;
for (b = 0; b < 10000; b++)
c = a * b;
}
noinline void f1(void)
{
f2();
f3();
}
int main()
{
int i;
for (i = 0; i < 100000; i++)
f1();
}
We run the example twice. (That's a simplified case. Of course, we
cannot find the scaling issue here. )
[lk@localhost perf_diff]$ gcc example_v1.c -o example
[lk@localhost perf_diff]$ perf record -o example_symoff_1.data ./example
[ perf record: Woken up 4 times to write data ]
[ perf record: Captured and wrote 0.808 MB example_symoff_1.data (~35314
samples) ]
[lk@localhost perf_diff]$ perf record -o example_symoff_2.data ./example
[ perf record: Woken up 4 times to write data ]
[ perf record: Captured and wrote 0.814 MB example_symoff_2.data (~35580
samples) ]
[lk@localhost perf_diff]$ perf diff -s symoff example_symoff_1.data
example_symoff_2.data
Event 'cycles'
Baseline Delta Symbol + Offset
........ ....... ....................................
0.00% _raw_spin_lock+0x13
account_process_tick+0x15a
apic_timer_interrupt+0x0
check_preempt_wakeup+0x174
0.00% f1+0x0
0.00% f1+0x1
0.00% f1+0xe
0.00% f2+0xb
0.03% +0.02% f2+0x14
0.02% f2+0x1a
30.75% -0.18% f2+0x1d
7.66% -0.18% f2+0x20
0.00% f2+0x29
7.69% +0.12% f2+0x2c
0.01% f2+0x33
0.01% f2+0x34
0.00% f3+0x0
7.67% +0.15% f3+0xd
0.01% f3+0x10
f3+0x13
3.95% -0.21% f3+0x17
3.91% -0.05% f3+0x20
3.74% +0.04% f3+0x22
4.00% -0.10% f3+0x2b
30.44% +0.45% f3+0x2e
0.02% f3+0x35
0.02% f3+0x36
0.00% ktime_get+0x9c
0.00% main+0x1a
main+0x21
0.00% native_read_tsc+0x6
0.00% native_write_msr_safe+0xa
rcu_irq_enter+0x88
0.00% rcu_note_context_switch+0x12
0.00% run_timer_softirq+0x292
timekeeping_update.constprop.7+0x9c
0.00% timerqueue_add+0x50
Signed-off-by: Kan Liang <[email protected]>
---
The patch is seperated from "[PATCH V4 0/3] perf tool: perf diff sort
changes" patch set.
The first patch of the patch set has been merged.
The second patch to support perf diff different binaries was submitted by
another thread.
This is the third patch to support symoff.
Changes since V4:
- Seperate from old patch set
- Symoff print format
- Check build_id
- Update man page
No change since V5
tools/perf/Documentation/perf-diff.txt | 2 +-
tools/perf/Documentation/perf-report.txt | 1 +
tools/perf/builtin-diff.c | 2 +-
tools/perf/util/hist.c | 7 ++++
tools/perf/util/hist.h | 1 +
tools/perf/util/sort.c | 67 ++++++++++++++++++++++++++++++++
tools/perf/util/sort.h | 2 +
7 files changed, 80 insertions(+), 2 deletions(-)
diff --git a/tools/perf/Documentation/perf-diff.txt b/tools/perf/Documentation/perf-diff.txt
index e463caa..4179ddfa 100644
--- a/tools/perf/Documentation/perf-diff.txt
+++ b/tools/perf/Documentation/perf-diff.txt
@@ -50,7 +50,7 @@ OPTIONS
-s::
--sort=::
- Sort by key(s): pid, comm, dso, symbol, cpu, parent, srcline.
+ Sort by key(s): pid, comm, dso, symbol, cpu, parent, srcline, symoff.
Please see description of --sort in the perf-report man page.
-t::
diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt
index 0927bf4..5b63311 100644
--- a/tools/perf/Documentation/perf-report.txt
+++ b/tools/perf/Documentation/perf-report.txt
@@ -70,6 +70,7 @@ OPTIONS
- pid: command and tid of the task
- dso: name of library or module executed at the time of sample
- symbol: name of function executed at the time of sample
+ - symoff: exact symbol + offset address executed at the time of sample.
- parent: name of function matched to the parent regex filter. Unmatched
entries are displayed as "[other]".
- cpu: cpu number the task ran at the time of sample
diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c
index 1ce425d..03a4001 100644
--- a/tools/perf/builtin-diff.c
+++ b/tools/perf/builtin-diff.c
@@ -744,7 +744,7 @@ static const struct option options[] = {
OPT_STRING('S', "symbols", &symbol_conf.sym_list_str, "symbol[,symbol...]",
"only consider these symbols"),
OPT_STRING('s', "sort", &sort_order, "key[,key2...]",
- "sort by key(s): pid, comm, dso, symbol, parent, cpu, srcline, ..."
+ "sort by key(s): pid, comm, dso, symbol, parent, cpu, srcline, symoff, ..."
" Please refer the man page for the complete list."),
OPT_STRING('t', "field-separator", &symbol_conf.field_sep, "separator",
"separator for columns, no spaces will be added between "
diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index 6e88b9e..062c3d4b 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -59,6 +59,7 @@ void hists__calc_col_len(struct hists *hists, struct hist_entry *h)
u16 len;
/*
+ * +6 accounts for '"+0xYYY ' symoff info
* +4 accounts for '[x] ' priv level info
* +2 accounts for 0x prefix on raw addresses
* +3 accounts for ' y ' symtab origin info
@@ -68,10 +69,16 @@ void hists__calc_col_len(struct hists *hists, struct hist_entry *h)
if (verbose)
symlen += BITS_PER_LONG / 4 + 2 + 3;
hists__new_col_len(hists, HISTC_SYMBOL, symlen);
+
+ symlen = h->ms.sym->namelen + 6;
+ hists__new_col_len(hists, HISTC_SYMOFF, symlen);
} else {
symlen = unresolved_col_width + 4 + 2;
hists__new_col_len(hists, HISTC_SYMBOL, symlen);
hists__set_unres_dso_col_len(hists, HISTC_DSO);
+
+ symlen = unresolved_col_width + 2;
+ hists__new_col_len(hists, HISTC_SYMOFF, symlen);
}
len = thread__comm_len(h->thread);
diff --git a/tools/perf/util/hist.h b/tools/perf/util/hist.h
index d0ef9a1..874b203 100644
--- a/tools/perf/util/hist.h
+++ b/tools/perf/util/hist.h
@@ -24,6 +24,7 @@ enum hist_filter {
enum hist_column {
HISTC_SYMBOL,
+ HISTC_SYMOFF,
HISTC_DSO,
HISTC_THREAD,
HISTC_COMM,
diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c
index 9139dda..2a1df9f 100644
--- a/tools/perf/util/sort.c
+++ b/tools/perf/util/sort.c
@@ -280,6 +280,65 @@ struct sort_entry sort_sym = {
.se_width_idx = HISTC_SYMBOL,
};
+static int64_t
+sort__symoff_cmp(struct hist_entry *left, struct hist_entry *right)
+{
+ return _sort__addr_cmp(left->ip, right->ip);
+}
+
+static int64_t
+sort__symoff_collapse(struct hist_entry *left, struct hist_entry *right)
+{
+ struct symbol *sym_l = left->ms.sym;
+ struct symbol *sym_r = right->ms.sym;
+ u64 symoff_l, symoff_r;
+ int64_t ret;
+
+ if (!sym_l || !sym_r)
+ return cmp_null(sym_l, sym_r);
+
+ ret = strcmp(sym_r->name, sym_l->name);
+ if (ret)
+ return ret;
+
+
+ symoff_l = left->ip - sym_l->start;
+ symoff_r = right->ip - sym_r->start;
+
+ return (int64_t)(symoff_r - symoff_l);
+}
+
+static int hist_entry__symoff_snprintf(struct hist_entry *he, char *bf,
+ size_t size, unsigned int width)
+{
+ struct map *map = he->ms.map;
+ struct symbol *sym = he->ms.sym;
+ size_t ret = 0;
+
+ if (sym) {
+ ret += repsep_snprintf(bf + ret, size - ret, "%s", sym->name);
+ ret += repsep_snprintf(bf + ret, size - ret, "+0x%llx",
+ he->ip - sym->start);
+
+ } else {
+ size_t len = BITS_PER_LONG / 4;
+
+ ret += repsep_snprintf(bf + ret, size - ret, "%-#.*llx", len,
+ map ? map->unmap_ip(map, he->ip) : he->ip);
+ }
+
+ ret += repsep_snprintf(bf + ret, size - ret, "%-*s",
+ width - ret, "");
+ return ret;
+}
+
+struct sort_entry sort_symoff = {
+ .se_header = "Symbol + Offset",
+ .se_cmp = sort__symoff_cmp,
+ .se_snprintf = hist_entry__symoff_snprintf,
+ .se_width_idx = HISTC_SYMOFF,
+};
+
/* --sort srcline */
static int64_t
@@ -1172,6 +1231,7 @@ static struct sort_dimension common_sort_dimensions[] = {
DIM(SORT_COMM, "comm", sort_comm),
DIM(SORT_DSO, "dso", sort_dso),
DIM(SORT_SYM, "symbol", sort_sym),
+ DIM(SORT_SYMOFF, "symoff", sort_symoff),
DIM(SORT_PARENT, "parent", sort_parent),
DIM(SORT_CPU, "cpu", sort_cpu),
DIM(SORT_SRCLINE, "srcline", sort_srcline),
@@ -1434,6 +1494,13 @@ int sort_dimension__add(const char *tok)
sort__has_sym = 1;
} else if (sd->entry == &sort_dso) {
sort__has_dso = 1;
+ } else if (sd->entry == &sort_symoff) {
+ /*
+ * For symoff sort key, not only the offset but also the
+ * symbol name should be compared.
+ */
+ if (sort__mode == SORT_MODE__DIFF)
+ sd->entry->se_collapse = sort__symoff_collapse;
}
return __sort_dimension__add(sd);
diff --git a/tools/perf/util/sort.h b/tools/perf/util/sort.h
index c03e4ff..ea0122f 100644
--- a/tools/perf/util/sort.h
+++ b/tools/perf/util/sort.h
@@ -38,6 +38,7 @@ extern enum sort_mode sort__mode;
extern struct sort_entry sort_comm;
extern struct sort_entry sort_dso;
extern struct sort_entry sort_sym;
+extern struct sort_entry sort_symoff;
extern struct sort_entry sort_parent;
extern struct sort_entry sort_dso_from;
extern struct sort_entry sort_dso_to;
@@ -161,6 +162,7 @@ enum sort_type {
SORT_COMM,
SORT_DSO,
SORT_SYM,
+ SORT_SYMOFF,
SORT_PARENT,
SORT_CPU,
SORT_SRCLINE,
--
1.8.3.2
From: Kan Liang <[email protected]>
symoff can support both same binaries and different binaries. However,
the offset may be changed for different binaries. This patch checks the
buildid of perf.data. If they are from different binaries, print a
warning to notify the user.
Signed-off-by: Kan Liang <[email protected]>
---
Changes since V5:
- Warning once.
- Print build-ids with --verbose
tools/perf/builtin-diff.c | 41 +++++++++++++++++++++++++++++++++++++++++
tools/perf/util/sort.c | 3 +++
tools/perf/util/sort.h | 1 +
3 files changed, 45 insertions(+)
diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c
index 03a4001..7f1cb6a 100644
--- a/tools/perf/builtin-diff.c
+++ b/tools/perf/builtin-diff.c
@@ -17,6 +17,7 @@
#include "util/symbol.h"
#include "util/util.h"
#include "util/data.h"
+#include "asm/bug.h"
#include <stdlib.h>
#include <math.h>
@@ -678,6 +679,43 @@ static void data__free(struct data__file *d)
}
}
+static void buildid_check(void)
+{
+ struct dsos *base_k_dsos = &data__files[0].session->machines.host.kernel_dsos;
+ struct dsos *base_u_dsos = &data__files[0].session->machines.host.user_dsos;
+ struct dsos *k_dsos_tmp, *u_dsos_tmp;
+ struct data__file *d;
+ bool k_warn, u_warn;
+ bool first = true;
+ int i;
+
+ data__for_each_file_new(i, d) {
+ k_dsos_tmp = &d->session->machines.host.kernel_dsos;
+ u_dsos_tmp = &d->session->machines.host.user_dsos;
+
+ k_warn = !dsos__build_ids_common_equal(base_k_dsos, k_dsos_tmp);
+ u_warn = !dsos__build_ids_common_equal(base_u_dsos, u_dsos_tmp);
+
+ WARN_ONCE(k_warn | u_warn, "The perf.data come from different %s%s%s. "
+ "The symbol offset may vary. Please apply --verbose for details.\n",
+ k_warn ? "kernel" : "",
+ (k_warn && u_warn) ? " and " : "",
+ u_warn ? "user binary" : "");
+
+ if (verbose) {
+ if (first) {
+ fprintf(stdout, "# ========%s (Baseline) build-ids\n", data__files[0].file.path);
+ machine__fprintf_dsos_buildid(&data__files[0].session->machines.host, stdout, NULL, 0);
+ fprintf(stdout, "# ========\n#\n");
+ first = false;
+ }
+ fprintf(stdout, "# ========%s build-ids\n", d->file.path);
+ machine__fprintf_dsos_buildid(&d->session->machines.host, stdout, NULL, 0);
+ fprintf(stdout, "# ========\n#\n");
+ }
+ }
+}
+
static int __cmd_diff(void)
{
struct data__file *d;
@@ -700,6 +738,9 @@ static int __cmd_diff(void)
perf_evlist__collapse_resort(d->session->evlist);
}
+ if (sort__has_symoff)
+ buildid_check();
+
data_process();
out_delete:
diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c
index 2a1df9f..07cfc4f 100644
--- a/tools/perf/util/sort.c
+++ b/tools/perf/util/sort.c
@@ -21,6 +21,7 @@ int sort__need_collapse = 0;
int sort__has_parent = 0;
int sort__has_sym = 0;
int sort__has_dso = 0;
+int sort__has_symoff = 0;
enum sort_mode sort__mode = SORT_MODE__NORMAL;
@@ -1495,6 +1496,7 @@ int sort_dimension__add(const char *tok)
} else if (sd->entry == &sort_dso) {
sort__has_dso = 1;
} else if (sd->entry == &sort_symoff) {
+ sort__has_symoff = 1;
/*
* For symoff sort key, not only the offset but also the
* symbol name should be compared.
@@ -1879,6 +1881,7 @@ void reset_output_field(void)
sort__has_parent = 0;
sort__has_sym = 0;
sort__has_dso = 0;
+ sort__has_symoff = 0;
field_order = NULL;
sort_order = NULL;
diff --git a/tools/perf/util/sort.h b/tools/perf/util/sort.h
index ea0122f..d2f9782 100644
--- a/tools/perf/util/sort.h
+++ b/tools/perf/util/sort.h
@@ -34,6 +34,7 @@ extern int have_ignore_callees;
extern int sort__need_collapse;
extern int sort__has_parent;
extern int sort__has_sym;
+extern int sort__has_symoff;
extern enum sort_mode sort__mode;
extern struct sort_entry sort_comm;
extern struct sort_entry sort_dso;
--
1.8.3.2
From: Kan Liang <[email protected]>
New function to compare the build_ids between different DSOs
This function is only interested in the common part of build_ids.
For example, dsos_a includes DSO A and DSO B. dsos_b includes DSO B and
DSO C. Only DSO B's build_id will be compared.
Signed-off-by: Kan Liang <[email protected]>
---
Changes since V5:
- Replace Arnaldo's dsos__build_ids_equal by bool dsos__build_ids_common_equal
- Only compare the common part of build-ids
tools/perf/util/dso.c | 20 ++++++++++++++++++++
tools/perf/util/dso.h | 2 ++
2 files changed, 22 insertions(+)
diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index 45be944..04416b9 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -1087,3 +1087,23 @@ enum dso_type dso__type(struct dso *dso, struct machine *machine)
return dso__type_fd(fd);
}
+
+bool dsos__build_ids_common_equal(struct dsos *dsos_a, struct dsos *dsos_b)
+{
+ struct dso *dso_a, *dso_b;
+
+ list_for_each_entry(dso_a, &dsos_a->head, node) {
+ dso_b = dsos__find(dsos_b, dso_a->short_name, true);
+ if (dso_b == NULL)
+ continue;
+ /*
+ * Only compare the common part of dsos.
+ */
+ if (dso_a->has_build_id && dso_b->has_build_id) {
+ if (memcmp(dso_a->build_id, dso_b->build_id, sizeof(dso_a->build_id)))
+ return false;
+ }
+ }
+
+ return true;
+}
diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
index 3782c82..e92217c 100644
--- a/tools/perf/util/dso.h
+++ b/tools/perf/util/dso.h
@@ -278,4 +278,6 @@ void dso__free_a2l(struct dso *dso);
enum dso_type dso__type(struct dso *dso, struct machine *machine);
+bool dsos__build_ids_common_equal(struct dsos *dsos_a, struct dsos *dsos_b);
+
#endif /* __PERF_DSO */
--
1.8.3.2
On Mon, Dec 01, 2014 at 09:40:10AM -0500, Kan Liang wrote:
SNIP
> +static int64_t
> +sort__symoff_collapse(struct hist_entry *left, struct hist_entry *right)
> +{
> + struct symbol *sym_l = left->ms.sym;
> + struct symbol *sym_r = right->ms.sym;
> + u64 symoff_l, symoff_r;
> + int64_t ret;
> +
> + if (!sym_l || !sym_r)
> + return cmp_null(sym_l, sym_r);
> +
> + ret = strcmp(sym_r->name, sym_l->name);
> + if (ret)
> + return ret;
> +
> +
> + symoff_l = left->ip - sym_l->start;
> + symoff_r = right->ip - sym_r->start;
> +
> + return (int64_t)(symoff_r - symoff_l);
> +}
> +
> +static int hist_entry__symoff_snprintf(struct hist_entry *he, char *bf,
> + size_t size, unsigned int width)
> +{
> + struct map *map = he->ms.map;
> + struct symbol *sym = he->ms.sym;
> + size_t ret = 0;
> +
> + if (sym) {
> + ret += repsep_snprintf(bf + ret, size - ret, "%s", sym->name);
> + ret += repsep_snprintf(bf + ret, size - ret, "+0x%llx",
> + he->ip - sym->start);
> +
> + } else {
> + size_t len = BITS_PER_LONG / 4;
> +
> + ret += repsep_snprintf(bf + ret, size - ret, "%-#.*llx", len,
> + map ? map->unmap_ip(map, he->ip) : he->ip);
> + }
> +
> + ret += repsep_snprintf(bf + ret, size - ret, "%-*s",
> + width - ret, "");
> + return ret;
> +}
> +
> +struct sort_entry sort_symoff = {
> + .se_header = "Symbol + Offset",
> + .se_cmp = sort__symoff_cmp,
> + .se_snprintf = hist_entry__symoff_snprintf,
> + .se_width_idx = HISTC_SYMOFF,
> +};
I might have missed this in previous discussions,
but do we also want just pure string comparison?
now I get:
0.30% +0.42% main+0x110
1.80% -0.45% main+0x115
0.05% -0.04% main+0x118
0.34% +0.49% main+0x11c
2.15% -0.22% main+0x120
0.41% +0.22% main+0x123
1.86% +0.04% main+0x12f
3.86% -0.69% main+0x133
0.02% main+0x137
3.80% -1.19% main+0x13d
0.26% +0.45% main+0x141
2.26% +1.41% main+0x145
8.78% -1.59% main+0x148
0.05% main+0x14c
1.40% -0.26% main+0x155
0.07% main+0x158
0.74% -0.03% main+0x15b
1.06% -0.17% main+0x160
0.31% +0.30% main+0x1a8
1.82% -0.51% main+0x1af
0.09% +0.07% main+0x1b1
0.05% main+0x1b4
could we add something like '-s symstr' to do
only symbol string comparison, so the previous
output would gather in single line like:
5.09% +2.07% main
otherwise the patchset looks ok to me:
Acked-by: Jiri Olsa <[email protected]>
thanks,
jirka
> On Mon, Dec 01, 2014 at 09:40:10AM -0500, Kan Liang wrote:
>
> SNIP
>
> > +static int64_t
> > +sort__symoff_collapse(struct hist_entry *left, struct hist_entry
> > +*right) {
> > + struct symbol *sym_l = left->ms.sym;
> > + struct symbol *sym_r = right->ms.sym;
> > + u64 symoff_l, symoff_r;
> > + int64_t ret;
> > +
> > + if (!sym_l || !sym_r)
> > + return cmp_null(sym_l, sym_r);
> > +
> > + ret = strcmp(sym_r->name, sym_l->name);
> > + if (ret)
> > + return ret;
> > +
> > +
> > + symoff_l = left->ip - sym_l->start;
> > + symoff_r = right->ip - sym_r->start;
> > +
> > + return (int64_t)(symoff_r - symoff_l); }
> > +
> > +static int hist_entry__symoff_snprintf(struct hist_entry *he, char *bf,
> > + size_t size, unsigned int width) {
> > + struct map *map = he->ms.map;
> > + struct symbol *sym = he->ms.sym;
> > + size_t ret = 0;
> > +
> > + if (sym) {
> > + ret += repsep_snprintf(bf + ret, size - ret, "%s", sym-
> >name);
> > + ret += repsep_snprintf(bf + ret, size - ret, "+0x%llx",
> > + he->ip - sym->start);
> > +
> > + } else {
> > + size_t len = BITS_PER_LONG / 4;
> > +
> > + ret += repsep_snprintf(bf + ret, size - ret, "%-#.*llx", len,
> > + map ? map->unmap_ip(map, he->ip) :
> he->ip);
> > + }
> > +
> > + ret += repsep_snprintf(bf + ret, size - ret, "%-*s",
> > + width - ret, "");
> > + return ret;
> > +}
> > +
> > +struct sort_entry sort_symoff = {
> > + .se_header = "Symbol + Offset",
> > + .se_cmp = sort__symoff_cmp,
> > + .se_snprintf = hist_entry__symoff_snprintf,
> > + .se_width_idx = HISTC_SYMOFF,
> > +};
>
> I might have missed this in previous discussions, but do we also want just
> pure string comparison?
>
> now I get:
> 0.30% +0.42% main+0x110
> 1.80% -0.45% main+0x115
> 0.05% -0.04% main+0x118
> 0.34% +0.49% main+0x11c
> 2.15% -0.22% main+0x120
> 0.41% +0.22% main+0x123
> 1.86% +0.04% main+0x12f
> 3.86% -0.69% main+0x133
> 0.02% main+0x137
> 3.80% -1.19% main+0x13d
> 0.26% +0.45% main+0x141
> 2.26% +1.41% main+0x145
> 8.78% -1.59% main+0x148
> 0.05% main+0x14c
> 1.40% -0.26% main+0x155
> 0.07% main+0x158
> 0.74% -0.03% main+0x15b
> 1.06% -0.17% main+0x160
> 0.31% +0.30% main+0x1a8
> 1.82% -0.51% main+0x1af
> 0.09% +0.07% main+0x1b1
> 0.05% main+0x1b4
>
> could we add something like '-s symstr' to do only symbol string
> comparison, so the previous output would gather in single line like:
>
> 5.09% +2.07% main
Yes, we have a patch to do that.
https://lkml.org/lkml/2014/11/21/367
The default sort key "symbol" do symbols names comparison.
The symoff here is an extension in case anyone want to do deeper analysis.
Thanks,
Kan
>
>
> otherwise the patchset looks ok to me:
> Acked-by: Jiri Olsa <[email protected]>
>
>
> thanks,
> jirka
On Mon, Dec 01, 2014 at 08:05:48PM +0000, Liang, Kan wrote:
SNIP
> > 0.05% main+0x14c
> > 1.40% -0.26% main+0x155
> > 0.07% main+0x158
> > 0.74% -0.03% main+0x15b
> > 1.06% -0.17% main+0x160
> > 0.31% +0.30% main+0x1a8
> > 1.82% -0.51% main+0x1af
> > 0.09% +0.07% main+0x1b1
> > 0.05% main+0x1b4
> >
> > could we add something like '-s symstr' to do only symbol string
> > comparison, so the previous output would gather in single line like:
> >
> > 5.09% +2.07% main
>
> Yes, we have a patch to do that.
> https://lkml.org/lkml/2014/11/21/367
> The default sort key "symbol" do symbols names comparison.
>
> The symoff here is an extension in case anyone want to do deeper analysis.
cool, I just acked it
thanks,
jirka