Commit 511e19b9 authored by Namhyung Kim's avatar Namhyung Kim Committed by Arnaldo Carvalho de Melo
Browse files

perf lock contention: Add -L/--lock-filter option 



The -L/--lock-filter option is to filter only given locks.  The locks
can be specified by address or name (if exists).

  $ sudo ./perf lock record -a  sleep 1

  $ sudo ./perf lock con -l
   contended  total wait  max wait  avg wait           address  symbol

          57     1.11 ms  42.83 us  19.54 us  ffff9f4140059000
          15   280.88 us  23.51 us  18.73 us  ffffffff9d007a40  jiffies_lock
           1    20.49 us  20.49 us  20.49 us  ffffffff9d0d50c0  rcu_state
           1     9.02 us   9.02 us   9.02 us  ffff9f41759e9ba0

  $ sudo ./perf lock con -L jiffies_lock,rcu_state
   contended  total wait  max wait  avg wait      type  caller

          15   280.88 us  23.51 us  18.73 us  spinlock  tick_sched_do_timer+0x93
           1    20.49 us  20.49 us  20.49 us  spinlock  __softirqentry_text_start+0xeb

  $ sudo ./perf lock con -L ffff9f4140059000
   contended  total wait  max wait  avg wait      type  caller

          38   779.40 us  42.83 us  20.51 us  spinlock  worker_thread+0x50
          11   216.30 us  39.87 us  19.66 us  spinlock  queue_work_on+0x39
           8   118.13 us  20.51 us  14.77 us  spinlock  kthread+0xe5

Committer testing:

  # uname -a
  Linux quaco 6.0.12-200.fc36.x86_64 #1 SMP PREEMPT_DYNAMIC Thu Dec 8 17:15:53 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux
  # perf lock record
  ^C[ perf record: Woken up 1 times to write data ]
  # perf lock con -L jiffies_lock,rcu_state
   contended   total wait     max wait     avg wait         type   caller

  # perf lock con
   contended   total wait     max wait     avg wait         type   caller

           1      9.06 us      9.06 us      9.06 us     spinlock   call_timer_fn+0x24
  # perf lock con -L call
  ignore unknown symbol: call
   contended   total wait     max wait     avg wait         type   caller

           1      9.06 us      9.06 us      9.06 us     spinlock   call_timer_fn+0x24
  #

Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Blake Jones <blakejones@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20221219201732.460111-5-namhyung@kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 529772c4

tools/perf/Documentation/perf-lock.txt

+4 −0
Original line number Diff line number Diff line
@@ -183,6 +183,10 @@ CONTENTION OPTIONS 
	Note that RW-variant of locks have :R and :W suffix.  Names without the

	suffix are shortcuts for the both variants.  Ex) rwsem = rwsem:R + rwsem:W.



-L::

--lock-filter=<value>::

	Show lock contention only for given lock addresses or names (comma separated list).





SEE ALSO

--------

tools/perf/builtin-lock.c

+134 −6
Original line number Diff line number Diff line
@@ -32,6 +32,7 @@ 
#include <semaphore.h>

#include <math.h>

#include <limits.h>

#include <ctype.h>



#include <linux/list.h>

#include <linux/hash.h>
@@ -995,24 +996,52 @@ static int report_lock_contention_begin_event(struct evsel *evsel, 
	unsigned int flags = evsel__intval(evsel, sample, "flags");

	u64 key;

	int i, ret;

	static bool kmap_loaded;

	struct machine *machine = &session->machines.host;

	struct map *kmap;

	struct symbol *sym;



	ret = get_key_by_aggr_mode(&key, addr, evsel, sample);

	if (ret < 0)

		return ret;



	if (!kmap_loaded) {

		unsigned long *addrs;



		/* make sure it loads the kernel map to find lock symbols */

		map__load(machine__kernel_map(machine));

		kmap_loaded = true;



		/* convert (kernel) symbols to addresses */

		for (i = 0; i < filters.nr_syms; i++) {

			sym = machine__find_kernel_symbol_by_name(machine,

								  filters.syms[i],

								  &kmap);

			if (sym == NULL) {

				pr_warning("ignore unknown symbol: %s\n",

					   filters.syms[i]);

				continue;

			}



			addrs = realloc(filters.addrs,

					(filters.nr_addrs + 1) * sizeof(*addrs));

			if (addrs == NULL) {

				pr_warning("memory allocation failure\n");

				return -ENOMEM;

			}



			addrs[filters.nr_addrs++] = kmap->unmap_ip(kmap, sym->start);

			filters.addrs = addrs;

		}

	}



	ls = lock_stat_find(key);

	if (!ls) {

		char buf[128];

		const char *name = "";

		struct machine *machine = &session->machines.host;

		struct map *kmap;

		struct symbol *sym;



		switch (aggr_mode) {

		case LOCK_AGGR_ADDR:

			/* make sure it loads the kernel map to find lock symbols */

			map__load(machine__kernel_map(machine));



			sym = machine__find_kernel_symbol(machine, key, &kmap);

			if (sym)

				name = sym->name;
@@ -1052,6 +1081,20 @@ static int report_lock_contention_begin_event(struct evsel *evsel, 
			return 0;

	}



	if (filters.nr_addrs) {

		bool found = false;



		for (i = 0; i < filters.nr_addrs; i++) {

			if (addr == filters.addrs[i]) {

				found = true;

				break;

			}

		}



		if (!found)

			return 0;

	}



	ts = thread_stat_findnew(sample->tid);

	if (!ts)

		return -ENOMEM;
@@ -1496,6 +1539,15 @@ static void lock_filter_finish(void) 
{

	zfree(&filters.types);

	filters.nr_types = 0;



	zfree(&filters.addrs);

	filters.nr_addrs = 0;



	for (int i = 0; i < filters.nr_syms; i++)

		free(filters.syms[i]);



	zfree(&filters.syms);

	filters.nr_syms = 0;

}



static void sort_contention_result(void)
@@ -1995,6 +2047,80 @@ static int parse_lock_type(const struct option *opt __maybe_unused, const char * 
	return ret;

}



static bool add_lock_addr(unsigned long addr)

{

	unsigned long *tmp;



	tmp = realloc(filters.addrs, (filters.nr_addrs + 1) * sizeof(*filters.addrs));

	if (tmp == NULL) {

		pr_err("Memory allocation failure\n");

		return false;

	}



	tmp[filters.nr_addrs++] = addr;

	filters.addrs = tmp;

	return true;

}



static bool add_lock_sym(char *name)

{

	char **tmp;

	char *sym = strdup(name);



	if (sym == NULL) {

		pr_err("Memory allocation failure\n");

		return false;

	}



	tmp = realloc(filters.syms, (filters.nr_syms + 1) * sizeof(*filters.syms));

	if (tmp == NULL) {

		pr_err("Memory allocation failure\n");

		free(sym);

		return false;

	}



	tmp[filters.nr_syms++] = sym;

	filters.syms = tmp;

	return true;

}



static int parse_lock_addr(const struct option *opt __maybe_unused, const char *str,

			   int unset __maybe_unused)

{

	char *s, *tmp, *tok;

	int ret = 0;

	u64 addr;



	s = strdup(str);

	if (s == NULL)

		return -1;



	for (tok = strtok_r(s, ", ", &tmp); tok; tok = strtok_r(NULL, ", ", &tmp)) {

		char *end;



		addr = strtoul(tok, &end, 16);

		if (*end == '\0') {

			if (!add_lock_addr(addr)) {

				ret = -1;

				break;

			}

			continue;

		}



		/*

		 * At this moment, we don't have kernel symbols.  Save the symbols

		 * in a separate list and resolve them to addresses later.

		 */

		if (!add_lock_sym(tok)) {

			ret = -1;

			break;

		}

	}



	free(s);

	return ret;

}



int cmd_lock(int argc, const char **argv)

{

	const struct option lock_options[] = {
@@ -2060,6 +2186,8 @@ int cmd_lock(int argc, const char **argv) 
	OPT_BOOLEAN('l', "lock-addr", &show_lock_addrs, "show lock stats by address"),

	OPT_CALLBACK('Y', "type-filter", NULL, "FLAGS",

		     "Filter specific type of locks", parse_lock_type),

	OPT_CALLBACK('L', "lock-filter", NULL, "ADDRS/NAMES",

		     "Filter specific address/symbol of locks", parse_lock_addr),

	OPT_PARENT(lock_options)

	};

tools/perf/util/lock-contention.h

+4 −0
Original line number Diff line number Diff line
@@ -7,7 +7,11 @@ 


struct lock_filter {

	int			nr_types;

	int			nr_addrs;

	int			nr_syms;

	unsigned int		*types;

	unsigned long		*addrs;

	char			**syms;

};



struct lock_stat {