freebsd-dev/usr.sbin/pmcstat/pmcpl_callgraph.c
Fabien Thomas eb707d6039 When an asm location cannot be resolved to a function the cost
will be spread as small value and then filtered by the threshold.
As a first step solution display the number of event that cannot
be resolved as a valid function location.

MFC after:	1week
2010-09-03 13:54:02 +00:00

688 lines
16 KiB
C

/*-
* Copyright (c) 2005-2007, Joseph Koshy
* Copyright (c) 2007 The FreeBSD Foundation
* All rights reserved.
*
* Portions of this software were developed by A. Joseph Koshy under
* sponsorship from the FreeBSD Foundation and Google, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* Transform a hwpmc(4) log into human readable form, and into
* gprof(1) compatible profiles.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/endian.h>
#include <sys/gmon.h>
#include <sys/imgact_aout.h>
#include <sys/imgact_elf.h>
#include <sys/mman.h>
#include <sys/pmc.h>
#include <sys/queue.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <netinet/in.h>
#include <assert.h>
#include <curses.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <gelf.h>
#include <libgen.h>
#include <limits.h>
#include <netdb.h>
#include <pmc.h>
#include <pmclog.h>
#include <sysexits.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "pmcstat.h"
#include "pmcstat_log.h"
#include "pmcstat_top.h"
#include "pmcpl_callgraph.h"
/* Get the sample value in percent related to nsamples. */
#define PMCPL_CG_COUNTP(a) \
((a)->pcg_count * 100.0 / nsamples)
/*
* The toplevel CG nodes (i.e., with rank == 0) are placed in a hash table.
*/
struct pmcstat_cgnode_hash_list pmcstat_cgnode_hash[PMCSTAT_NHASH];
int pmcstat_cgnode_hash_count;
static pmcstat_interned_string pmcstat_previous_filename_printed;
static struct pmcstat_cgnode *
pmcstat_cgnode_allocate(struct pmcstat_image *image, uintfptr_t pc)
{
struct pmcstat_cgnode *cg;
if ((cg = malloc(sizeof(*cg))) == NULL)
err(EX_OSERR, "ERROR: Cannot allocate callgraph node");
cg->pcg_image = image;
cg->pcg_func = pc;
cg->pcg_count = 0;
cg->pcg_nchildren = 0;
LIST_INIT(&cg->pcg_children);
return (cg);
}
/*
* Free a node and its children.
*/
static void
pmcstat_cgnode_free(struct pmcstat_cgnode *cg)
{
struct pmcstat_cgnode *cgc, *cgtmp;
LIST_FOREACH_SAFE(cgc, &cg->pcg_children, pcg_sibling, cgtmp)
pmcstat_cgnode_free(cgc);
free(cg);
}
/*
* Look for a callgraph node associated with pmc `pmcid' in the global
* hash table that corresponds to the given `pc' value in the process
* `pp'.
*/
static struct pmcstat_cgnode *
pmcstat_cgnode_hash_lookup_pc(struct pmcstat_process *pp, pmc_id_t pmcid,
uintfptr_t pc, int usermode)
{
struct pmcstat_pcmap *ppm;
struct pmcstat_symbol *sym;
struct pmcstat_image *image;
struct pmcstat_cgnode *cg;
struct pmcstat_cgnode_hash *h;
uintfptr_t loadaddress;
unsigned int i, hash;
ppm = pmcstat_process_find_map(usermode ? pp : pmcstat_kernproc, pc);
if (ppm == NULL)
return (NULL);
image = ppm->ppm_image;
loadaddress = ppm->ppm_lowpc + image->pi_vaddr - image->pi_start;
pc -= loadaddress; /* Convert to an offset in the image. */
/*
* Try determine the function at this offset. If we can't
* find a function round leave the `pc' value alone.
*/
if ((sym = pmcstat_symbol_search(image, pc)) != NULL)
pc = sym->ps_start;
else
pmcstat_stats.ps_samples_unknown_function++;
for (hash = i = 0; i < sizeof(uintfptr_t); i++)
hash += (pc >> i) & 0xFF;
hash &= PMCSTAT_HASH_MASK;
cg = NULL;
LIST_FOREACH(h, &pmcstat_cgnode_hash[hash], pch_next)
{
if (h->pch_pmcid != pmcid)
continue;
cg = h->pch_cgnode;
assert(cg != NULL);
if (cg->pcg_image == image && cg->pcg_func == pc)
return (cg);
}
/*
* We haven't seen this (pmcid, pc) tuple yet, so allocate a
* new callgraph node and a new hash table entry for it.
*/
cg = pmcstat_cgnode_allocate(image, pc);
if ((h = malloc(sizeof(*h))) == NULL)
err(EX_OSERR, "ERROR: Could not allocate callgraph node");
h->pch_pmcid = pmcid;
h->pch_cgnode = cg;
LIST_INSERT_HEAD(&pmcstat_cgnode_hash[hash], h, pch_next);
pmcstat_cgnode_hash_count++;
return (cg);
}
/*
* Compare two callgraph nodes for sorting.
*/
static int
pmcstat_cgnode_compare(const void *a, const void *b)
{
const struct pmcstat_cgnode *const *pcg1, *const *pcg2, *cg1, *cg2;
pcg1 = (const struct pmcstat_cgnode *const *) a;
cg1 = *pcg1;
pcg2 = (const struct pmcstat_cgnode *const *) b;
cg2 = *pcg2;
/* Sort in reverse order */
if (cg1->pcg_count < cg2->pcg_count)
return (1);
if (cg1->pcg_count > cg2->pcg_count)
return (-1);
return (0);
}
/*
* Find (allocating if a needed) a callgraph node in the given
* parent with the same (image, pcoffset) pair.
*/
static struct pmcstat_cgnode *
pmcstat_cgnode_find(struct pmcstat_cgnode *parent, struct pmcstat_image *image,
uintfptr_t pcoffset)
{
struct pmcstat_cgnode *child;
LIST_FOREACH(child, &parent->pcg_children, pcg_sibling) {
if (child->pcg_image == image &&
child->pcg_func == pcoffset)
return (child);
}
/*
* Allocate a new structure.
*/
child = pmcstat_cgnode_allocate(image, pcoffset);
/*
* Link it into the parent.
*/
LIST_INSERT_HEAD(&parent->pcg_children, child, pcg_sibling);
parent->pcg_nchildren++;
return (child);
}
/*
* Print one callgraph node. The output format is:
*
* indentation %(parent's samples) #nsamples function@object
*/
static void
pmcstat_cgnode_print(struct pmcstat_cgnode *cg, int depth, uint32_t total)
{
uint32_t n;
const char *space;
struct pmcstat_symbol *sym;
struct pmcstat_cgnode **sortbuffer, **cgn, *pcg;
space = " ";
if (depth > 0)
(void) fprintf(args.pa_graphfile, "%*s", depth, space);
if (cg->pcg_count == total)
(void) fprintf(args.pa_graphfile, "100.0%% ");
else
(void) fprintf(args.pa_graphfile, "%05.2f%% ",
100.0 * cg->pcg_count / total);
n = fprintf(args.pa_graphfile, " [%u] ", cg->pcg_count);
/* #samples is a 12 character wide field. */
if (n < 12)
(void) fprintf(args.pa_graphfile, "%*s", 12 - n, space);
if (depth > 0)
(void) fprintf(args.pa_graphfile, "%*s", depth, space);
sym = pmcstat_symbol_search(cg->pcg_image, cg->pcg_func);
if (sym)
(void) fprintf(args.pa_graphfile, "%s",
pmcstat_string_unintern(sym->ps_name));
else
(void) fprintf(args.pa_graphfile, "%p",
(void *) (cg->pcg_image->pi_vaddr + cg->pcg_func));
if (pmcstat_previous_filename_printed !=
cg->pcg_image->pi_fullpath) {
pmcstat_previous_filename_printed = cg->pcg_image->pi_fullpath;
(void) fprintf(args.pa_graphfile, " @ %s\n",
pmcstat_string_unintern(
pmcstat_previous_filename_printed));
} else
(void) fprintf(args.pa_graphfile, "\n");
if (cg->pcg_nchildren == 0)
return;
if ((sortbuffer = (struct pmcstat_cgnode **)
malloc(sizeof(struct pmcstat_cgnode *) *
cg->pcg_nchildren)) == NULL)
err(EX_OSERR, "ERROR: Cannot print callgraph");
cgn = sortbuffer;
LIST_FOREACH(pcg, &cg->pcg_children, pcg_sibling)
*cgn++ = pcg;
assert(cgn - sortbuffer == (int) cg->pcg_nchildren);
qsort(sortbuffer, cg->pcg_nchildren, sizeof(struct pmcstat_cgnode *),
pmcstat_cgnode_compare);
for (cgn = sortbuffer, n = 0; n < cg->pcg_nchildren; n++, cgn++)
pmcstat_cgnode_print(*cgn, depth+1, cg->pcg_count);
free(sortbuffer);
}
/*
* Record a callchain.
*/
void
pmcpl_cg_process(struct pmcstat_process *pp, struct pmcstat_pmcrecord *pmcr,
uint32_t nsamples, uintfptr_t *cc, int usermode, uint32_t cpu)
{
uintfptr_t pc, loadaddress;
uint32_t n;
struct pmcstat_image *image;
struct pmcstat_pcmap *ppm;
struct pmcstat_symbol *sym;
struct pmcstat_cgnode *parent, *child;
struct pmcstat_process *km;
pmc_id_t pmcid;
(void) cpu;
/*
* Find the callgraph node recorded in the global hash table
* for this (pmcid, pc).
*/
pc = cc[0];
pmcid = pmcr->pr_pmcid;
parent = pmcstat_cgnode_hash_lookup_pc(pp, pmcid, pc, usermode);
if (parent == NULL) {
pmcstat_stats.ps_callchain_dubious_frames++;
pmcr->pr_dubious_frames++;
return;
}
parent->pcg_count++;
/*
* For each return address in the call chain record, subject
* to the maximum depth desired.
* - Find the image associated with the sample. Stop if there
* there is no valid image at that address.
* - Find the function that overlaps the return address.
* - If found: use the start address of the function.
* If not found (say an object's symbol table is not present or
* is incomplete), round down to th gprof bucket granularity.
* - Convert return virtual address to an offset in the image.
* - Look for a child with the same {offset,image} tuple,
* inserting one if needed.
* - Increment the count of occurrences of the child.
*/
km = pmcstat_kernproc;
for (n = 1; n < (uint32_t) args.pa_graphdepth && n < nsamples; n++,
parent = child) {
pc = cc[n];
ppm = pmcstat_process_find_map(usermode ? pp : km, pc);
if (ppm == NULL) {
/* Detect full frame capture (kernel + user). */
if (!usermode) {
ppm = pmcstat_process_find_map(pp, pc);
if (ppm != NULL)
km = pp;
}
}
if (ppm == NULL)
return;
image = ppm->ppm_image;
loadaddress = ppm->ppm_lowpc + image->pi_vaddr -
image->pi_start;
pc -= loadaddress;
if ((sym = pmcstat_symbol_search(image, pc)) != NULL)
pc = sym->ps_start;
child = pmcstat_cgnode_find(parent, image, pc);
child->pcg_count++;
}
}
/*
* Printing a callgraph for a PMC.
*/
static void
pmcstat_callgraph_print_for_pmcid(struct pmcstat_pmcrecord *pmcr)
{
int n, nentries;
uint32_t nsamples;
pmc_id_t pmcid;
struct pmcstat_cgnode **sortbuffer, **cgn;
struct pmcstat_cgnode_hash *pch;
/*
* We pull out all callgraph nodes in the top-level hash table
* with a matching PMC id. We then sort these based on the
* frequency of occurrence. Each callgraph node is then
* printed.
*/
nsamples = 0;
pmcid = pmcr->pr_pmcid;
if ((sortbuffer = (struct pmcstat_cgnode **)
malloc(sizeof(struct pmcstat_cgnode *) *
pmcstat_cgnode_hash_count)) == NULL)
err(EX_OSERR, "ERROR: Cannot sort callgraph");
cgn = sortbuffer;
for (n = 0; n < PMCSTAT_NHASH; n++)
LIST_FOREACH(pch, &pmcstat_cgnode_hash[n], pch_next)
if (pch->pch_pmcid == pmcid) {
nsamples += pch->pch_cgnode->pcg_count;
*cgn++ = pch->pch_cgnode;
}
nentries = cgn - sortbuffer;
assert(nentries <= pmcstat_cgnode_hash_count);
if (nentries == 0) {
free(sortbuffer);
return;
}
qsort(sortbuffer, nentries, sizeof(struct pmcstat_cgnode *),
pmcstat_cgnode_compare);
(void) fprintf(args.pa_graphfile,
"@ %s [%u samples]\n\n",
pmcstat_string_unintern(pmcr->pr_pmcname),
nsamples);
for (cgn = sortbuffer, n = 0; n < nentries; n++, cgn++) {
pmcstat_previous_filename_printed = NULL;
pmcstat_cgnode_print(*cgn, 0, nsamples);
(void) fprintf(args.pa_graphfile, "\n");
}
free(sortbuffer);
}
/*
* Print out callgraphs.
*/
static void
pmcstat_callgraph_print(void)
{
struct pmcstat_pmcrecord *pmcr;
LIST_FOREACH(pmcr, &pmcstat_pmcs, pr_next)
pmcstat_callgraph_print_for_pmcid(pmcr);
}
static void
pmcstat_cgnode_topprint(struct pmcstat_cgnode *cg,
int depth, uint32_t nsamples)
{
int v_attrs, vs_len, ns_len, width, len, n, nchildren;
float v;
char ns[30], vs[10];
struct pmcstat_symbol *sym;
struct pmcstat_cgnode **sortbuffer, **cgn, *pcg;
(void) depth;
/* Format value. */
v = PMCPL_CG_COUNTP(cg);
snprintf(vs, sizeof(vs), "%.1f", v);
v_attrs = PMCSTAT_ATTRPERCENT(v);
/* Format name. */
sym = pmcstat_symbol_search(cg->pcg_image, cg->pcg_func);
if (sym != NULL) {
snprintf(ns, sizeof(ns), "%s",
pmcstat_string_unintern(sym->ps_name));
} else
snprintf(ns, sizeof(ns), "%p",
(void *)cg->pcg_func);
PMCSTAT_ATTRON(v_attrs);
PMCSTAT_PRINTW("%5.5s", vs);
PMCSTAT_ATTROFF(v_attrs);
PMCSTAT_PRINTW(" %-10.10s %-20.20s",
pmcstat_string_unintern(cg->pcg_image->pi_name),
ns);
nchildren = cg->pcg_nchildren;
if (nchildren == 0) {
PMCSTAT_PRINTW("\n");
return;
}
width = pmcstat_displaywidth - 40;
if ((sortbuffer = (struct pmcstat_cgnode **)
malloc(sizeof(struct pmcstat_cgnode *) *
nchildren)) == NULL)
err(EX_OSERR, "ERROR: Cannot print callgraph");
cgn = sortbuffer;
LIST_FOREACH(pcg, &cg->pcg_children, pcg_sibling)
*cgn++ = pcg;
assert(cgn - sortbuffer == (int)nchildren);
qsort(sortbuffer, nchildren, sizeof(struct pmcstat_cgnode *),
pmcstat_cgnode_compare);
/* Count how many callers. */
for (cgn = sortbuffer, n = 0; n < nchildren; n++, cgn++) {
pcg = *cgn;
v = PMCPL_CG_COUNTP(pcg);
if (v < pmcstat_threshold)
break;
}
nchildren = n;
for (cgn = sortbuffer, n = 0; n < nchildren; n++, cgn++) {
pcg = *cgn;
/* Format value. */
if (nchildren > 1) {
v = PMCPL_CG_COUNTP(pcg);
vs_len = snprintf(vs, sizeof(vs), ":%.1f", v);
v_attrs = PMCSTAT_ATTRPERCENT(v);
} else
vs_len = 0;
/* Format name. */
sym = pmcstat_symbol_search(pcg->pcg_image, pcg->pcg_func);
if (sym != NULL) {
ns_len = snprintf(ns, sizeof(ns), "%s",
pmcstat_string_unintern(sym->ps_name));
} else
ns_len = snprintf(ns, sizeof(ns), "%p",
(void *)pcg->pcg_func);
len = ns_len + vs_len + 1;
if (width - len < 0) {
PMCSTAT_PRINTW(" ...");
break;
}
width -= len;
PMCSTAT_PRINTW(" %s", ns);
if (nchildren > 1) {
PMCSTAT_ATTRON(v_attrs);
PMCSTAT_PRINTW("%s", vs);
PMCSTAT_ATTROFF(v_attrs);
}
}
PMCSTAT_PRINTW("\n");
free(sortbuffer);
}
/*
* Top mode display.
*/
void
pmcpl_cg_topdisplay(void)
{
int n, nentries;
uint32_t nsamples;
struct pmcstat_cgnode **sortbuffer, **cgn;
struct pmcstat_cgnode_hash *pch;
struct pmcstat_pmcrecord *pmcr;
pmcr = pmcstat_pmcindex_to_pmcr(pmcstat_pmcinfilter);
if (!pmcr)
err(EX_SOFTWARE, "ERROR: invalid pmcindex");
/*
* We pull out all callgraph nodes in the top-level hash table
* with a matching PMC index. We then sort these based on the
* frequency of occurrence. Each callgraph node is then
* printed.
*/
nsamples = 0;
if ((sortbuffer = (struct pmcstat_cgnode **)
malloc(sizeof(struct pmcstat_cgnode *) *
pmcstat_cgnode_hash_count)) == NULL)
err(EX_OSERR, "ERROR: Cannot sort callgraph");
cgn = sortbuffer;
for (n = 0; n < PMCSTAT_NHASH; n++)
LIST_FOREACH(pch, &pmcstat_cgnode_hash[n], pch_next)
if (pmcr == NULL || pch->pch_pmcid == pmcr->pr_pmcid) {
nsamples += pch->pch_cgnode->pcg_count;
*cgn++ = pch->pch_cgnode;
}
nentries = cgn - sortbuffer;
assert(nentries <= pmcstat_cgnode_hash_count);
if (nentries == 0) {
free(sortbuffer);
return;
}
qsort(sortbuffer, nentries, sizeof(struct pmcstat_cgnode *),
pmcstat_cgnode_compare);
PMCSTAT_PRINTW("%5.5s %-10.10s %-20.20s %s\n",
"%SAMP", "IMAGE", "FUNCTION", "CALLERS");
nentries = min(pmcstat_displayheight - 2, nentries);
for (cgn = sortbuffer, n = 0; n < nentries; n++, cgn++) {
if (PMCPL_CG_COUNTP(*cgn) < pmcstat_threshold)
break;
pmcstat_cgnode_topprint(*cgn, 0, nsamples);
}
free(sortbuffer);
}
/*
* Handle top mode keypress.
*/
int
pmcpl_cg_topkeypress(int c, WINDOW *w)
{
(void) c; (void) w;
return 0;
}
int
pmcpl_cg_init(void)
{
int i;
pmcstat_cgnode_hash_count = 0;
pmcstat_previous_filename_printed = NULL;
for (i = 0; i < PMCSTAT_NHASH; i++) {
LIST_INIT(&pmcstat_cgnode_hash[i]);
}
return (0);
}
void
pmcpl_cg_shutdown(FILE *mf)
{
int i;
struct pmcstat_cgnode_hash *pch, *pchtmp;
(void) mf;
if (args.pa_flags & FLAG_DO_CALLGRAPHS)
pmcstat_callgraph_print();
/*
* Free memory.
*/
for (i = 0; i < PMCSTAT_NHASH; i++) {
LIST_FOREACH_SAFE(pch, &pmcstat_cgnode_hash[i], pch_next,
pchtmp) {
pmcstat_cgnode_free(pch->pch_cgnode);
LIST_REMOVE(pch, pch_next);
free(pch);
}
}
}