perf tools: Allow sorting by symbol size

Add new sort key 'symbol_size' to allow user to sort by symbol size, or
(more usefully) display the symbol size using --fields=...,symbol_size.

Committer note:

Testing it together with the recently added -q, to remove the headers,
and using the '+' sign with -s, to add the symbol_size sort order to
the default, which is '-s/--sort comm,dso,symbol':

  # perf report -q -s +symbol_size | head -10
  10.39%  swapper       [kernel.vmlinux] [k] intel_idle               270
   3.45%  swapper       [kernel.vmlinux] [k] update_blocked_averages 1546
   2.61%  swapper       [kernel.vmlinux] [k] update_load_avg         1292
   2.36%  swapper       [kernel.vmlinux] [k] update_cfs_shares        240
   1.83%  swapper       [kernel.vmlinux] [k] __hrtimer_run_queues     606
   1.74%  swapper       [kernel.vmlinux] [k] update_cfs_rq_load_avg. 1187
   1.66%  swapper       [kernel.vmlinux] [k] apic_timer_interrupt     152
   1.60%  CPU 0/KVM     [kvm]            [k] kvm_set_msr_common      3046
   1.60%  gnome-shell   libglib-2.0.so.0 [.] g_slist_find              37
   1.46%  gnome-termina libglib-2.0.so.0 [.] g_hash_table_lookup      370
  #
Signed-off-by: Charles Baylis <charles.baylis@linaro.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Maxim Kuvyrkov <maxim.kuvyrkov@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1487943176-13840-1-git-send-email-charles.baylis@linaro.org
[ Use symbol__size(), remove needless %lld + (long long) casting ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/Documentation/perf-report.txt

@@ -80,6 +80,7 @@ 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
+	- symbol_size: size of function 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

tools/perf/util/hist.h

@@ -57,6 +57,7 @@ enum hist_column {
 	HISTC_SRCLINE_FROM,
 	HISTC_SRCLINE_TO,
 	HISTC_TRACE,
+	HISTC_SYM_SIZE,
 	HISTC_NR_COLS, /* Last entry */
 };
 

tools/perf/util/sort.c

@@ -1396,6 +1396,46 @@ struct sort_entry sort_transaction = {
 	.se_width_idx	= HISTC_TRANSACTION,
 };
 
+/* --sort symbol_size */
+
+static int64_t _sort__sym_size_cmp(struct symbol *sym_l, struct symbol *sym_r)
+{
+	int64_t size_l = sym_l != NULL ? symbol__size(sym_l) : 0;
+	int64_t size_r = sym_r != NULL ? symbol__size(sym_r) : 0;
+
+	return size_l < size_r ? -1 :
+		size_l == size_r ? 0 : 1;
+}
+
+static int64_t
+sort__sym_size_cmp(struct hist_entry *left, struct hist_entry *right)
+{
+	return _sort__sym_size_cmp(right->ms.sym, left->ms.sym);
+}
+
+static int _hist_entry__sym_size_snprintf(struct symbol *sym, char *bf,
+					  size_t bf_size, unsigned int width)
+{
+	if (sym)
+		return repsep_snprintf(bf, bf_size, "%*d", width, symbol__size(sym));
+
+	return repsep_snprintf(bf, bf_size, "%*s", width, "unknown");
+}
+
+static int hist_entry__sym_size_snprintf(struct hist_entry *he, char *bf,
+					 size_t size, unsigned int width)
+{
+	return _hist_entry__sym_size_snprintf(he->ms.sym, bf, size, width);
+}
+
+struct sort_entry sort_sym_size = {
+	.se_header	= "Symbol size",
+	.se_cmp		= sort__sym_size_cmp,
+	.se_snprintf	= hist_entry__sym_size_snprintf,
+	.se_width_idx	= HISTC_SYM_SIZE,
+};
+
+
 struct sort_dimension {
 	const char		*name;
 	struct sort_entry	*entry;
@@ -1418,6 +1458,7 @@ static struct sort_dimension common_sort_dimensions[] = {
 	DIM(SORT_GLOBAL_WEIGHT, "weight", sort_global_weight),
 	DIM(SORT_TRANSACTION, "transaction", sort_transaction),
 	DIM(SORT_TRACE, "trace", sort_trace),
+	DIM(SORT_SYM_SIZE, "symbol_size", sort_sym_size),
 };
 
 #undef DIM

tools/perf/util/sort.h

@@ -211,6 +211,7 @@ enum sort_type {
 	SORT_GLOBAL_WEIGHT,
 	SORT_TRANSACTION,
 	SORT_TRACE,
+	SORT_SYM_SIZE,
 
 	/* branch stack specific sort keys */
 	__SORT_BRANCH_STACK,