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Message-ID: <ZyPcRn9UdigvUmuE@x1>
Date: Thu, 31 Oct 2024 16:36:38 -0300
From: Arnaldo Carvalho de Melo <acme@...nel.org>
To: Ian Rogers <irogers@...gle.com>
Cc: Peter Zijlstra <peterz@...radead.org>, Ingo Molnar <mingo@...hat.com>,
Namhyung Kim <namhyung@...nel.org>,
Mark Rutland <mark.rutland@....com>,
Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
Jiri Olsa <jolsa@...nel.org>,
Adrian Hunter <adrian.hunter@...el.com>,
Kan Liang <kan.liang@...ux.intel.com>,
James Clark <james.clark@...aro.org>,
Howard Chu <howardchu95@...il.com>,
Athira Jajeev <atrajeev@...ux.vnet.ibm.com>,
Michael Petlan <mpetlan@...hat.com>,
Veronika Molnarova <vmolnaro@...hat.com>,
Dapeng Mi <dapeng1.mi@...ux.intel.com>,
Thomas Richter <tmricht@...ux.ibm.com>,
Ilya Leoshkevich <iii@...ux.ibm.com>,
Colin Ian King <colin.i.king@...il.com>,
Weilin Wang <weilin.wang@...el.com>,
Andi Kleen <ak@...ux.intel.com>,
Josh Poimboeuf <jpoimboe@...hat.com>, linux-kernel@...r.kernel.org,
linux-perf-users@...r.kernel.org
Subject: Re: [PATCH v5 14/21] perf lock: Move common lock contention code to
new file
On Wed, Oct 30, 2024 at 06:42:45PM -0700, Ian Rogers wrote:
> Avoid references from util code to builtin-lock that require python
> stubs. Move the functions and related variables to
> util/lock-contention.c. Add max_stack_depth parameter to
> match_callstack_filter to avoid sharing a global variable.
Acked-by: Arnaldo Carvalho de Melo <acme@...hat.com>
> Signed-off-by: Ian Rogers <irogers@...gle.com>
> ---
> tools/perf/builtin-lock.c | 137 +--------------------
> tools/perf/util/Build | 1 +
> tools/perf/util/bpf_lock_contention.c | 2 +-
> tools/perf/util/lock-contention.c | 170 ++++++++++++++++++++++++++
> tools/perf/util/lock-contention.h | 37 ++----
> tools/perf/util/python.c | 17 ---
> 6 files changed, 185 insertions(+), 179 deletions(-)
> create mode 100644 tools/perf/util/lock-contention.c
>
> diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c
> index 062e2b56a2ab..f66948b1fbed 100644
> --- a/tools/perf/builtin-lock.c
> +++ b/tools/perf/builtin-lock.c
> @@ -46,15 +46,6 @@
> static struct perf_session *session;
> static struct target target;
>
> -/* based on kernel/lockdep.c */
> -#define LOCKHASH_BITS 12
> -#define LOCKHASH_SIZE (1UL << LOCKHASH_BITS)
> -
> -static struct hlist_head *lockhash_table;
> -
> -#define __lockhashfn(key) hash_long((unsigned long)key, LOCKHASH_BITS)
> -#define lockhashentry(key) (lockhash_table + __lockhashfn((key)))
> -
> static struct rb_root thread_stats;
>
> static bool combine_locks;
> @@ -67,24 +58,13 @@ static unsigned long bpf_map_entries = MAX_ENTRIES;
> static int max_stack_depth = CONTENTION_STACK_DEPTH;
> static int stack_skip = CONTENTION_STACK_SKIP;
> static int print_nr_entries = INT_MAX / 2;
> -static LIST_HEAD(callstack_filters);
> static const char *output_name = NULL;
> static FILE *lock_output;
>
> -struct callstack_filter {
> - struct list_head list;
> - char name[];
> -};
> -
> static struct lock_filter filters;
>
> static enum lock_aggr_mode aggr_mode = LOCK_AGGR_ADDR;
>
> -static bool needs_callstack(void)
> -{
> - return !list_empty(&callstack_filters);
> -}
> -
> static struct thread_stat *thread_stat_find(u32 tid)
> {
> struct rb_node *node;
> @@ -477,93 +457,6 @@ static struct lock_stat *pop_from_result(void)
> return container_of(node, struct lock_stat, rb);
> }
>
> -struct lock_stat *lock_stat_find(u64 addr)
> -{
> - struct hlist_head *entry = lockhashentry(addr);
> - struct lock_stat *ret;
> -
> - hlist_for_each_entry(ret, entry, hash_entry) {
> - if (ret->addr == addr)
> - return ret;
> - }
> - return NULL;
> -}
> -
> -struct lock_stat *lock_stat_findnew(u64 addr, const char *name, int flags)
> -{
> - struct hlist_head *entry = lockhashentry(addr);
> - struct lock_stat *ret, *new;
> -
> - hlist_for_each_entry(ret, entry, hash_entry) {
> - if (ret->addr == addr)
> - return ret;
> - }
> -
> - new = zalloc(sizeof(struct lock_stat));
> - if (!new)
> - goto alloc_failed;
> -
> - new->addr = addr;
> - new->name = strdup(name);
> - if (!new->name) {
> - free(new);
> - goto alloc_failed;
> - }
> -
> - new->flags = flags;
> - new->wait_time_min = ULLONG_MAX;
> -
> - hlist_add_head(&new->hash_entry, entry);
> - return new;
> -
> -alloc_failed:
> - pr_err("memory allocation failed\n");
> - return NULL;
> -}
> -
> -bool match_callstack_filter(struct machine *machine, u64 *callstack)
> -{
> - struct map *kmap;
> - struct symbol *sym;
> - u64 ip;
> - const char *arch = perf_env__arch(machine->env);
> -
> - if (list_empty(&callstack_filters))
> - return true;
> -
> - for (int i = 0; i < max_stack_depth; i++) {
> - struct callstack_filter *filter;
> -
> - /*
> - * In powerpc, the callchain saved by kernel always includes
> - * first three entries as the NIP (next instruction pointer),
> - * LR (link register), and the contents of LR save area in the
> - * second stack frame. In certain scenarios its possible to have
> - * invalid kernel instruction addresses in either LR or the second
> - * stack frame's LR. In that case, kernel will store that address as
> - * zero.
> - *
> - * The below check will continue to look into callstack,
> - * incase first or second callstack index entry has 0
> - * address for powerpc.
> - */
> - if (!callstack || (!callstack[i] && (strcmp(arch, "powerpc") ||
> - (i != 1 && i != 2))))
> - break;
> -
> - ip = callstack[i];
> - sym = machine__find_kernel_symbol(machine, ip, &kmap);
> - if (sym == NULL)
> - continue;
> -
> - list_for_each_entry(filter, &callstack_filters, list) {
> - if (strstr(sym->name, filter->name))
> - return true;
> - }
> - }
> - return false;
> -}
> -
> struct trace_lock_handler {
> /* it's used on CONFIG_LOCKDEP */
> int (*acquire_event)(struct evsel *evsel,
> @@ -1165,7 +1058,7 @@ static int report_lock_contention_begin_event(struct evsel *evsel,
> if (callstack == NULL)
> return -ENOMEM;
>
> - if (!match_callstack_filter(machine, callstack)) {
> + if (!match_callstack_filter(machine, callstack, max_stack_depth)) {
> free(callstack);
> return 0;
> }
> @@ -2449,34 +2342,6 @@ static int parse_lock_addr(const struct option *opt __maybe_unused, const char *
> return ret;
> }
>
> -static int parse_call_stack(const struct option *opt __maybe_unused, const char *str,
> - int unset __maybe_unused)
> -{
> - char *s, *tmp, *tok;
> - int ret = 0;
> -
> - s = strdup(str);
> - if (s == NULL)
> - return -1;
> -
> - for (tok = strtok_r(s, ", ", &tmp); tok; tok = strtok_r(NULL, ", ", &tmp)) {
> - struct callstack_filter *entry;
> -
> - entry = malloc(sizeof(*entry) + strlen(tok) + 1);
> - if (entry == NULL) {
> - pr_err("Memory allocation failure\n");
> - free(s);
> - return -1;
> - }
> -
> - strcpy(entry->name, tok);
> - list_add_tail(&entry->list, &callstack_filters);
> - }
> -
> - free(s);
> - return ret;
> -}
> -
> static int parse_output(const struct option *opt __maybe_unused, const char *str,
> int unset __maybe_unused)
> {
> diff --git a/tools/perf/util/Build b/tools/perf/util/Build
> index 340544a6f5ec..3c6cd8d81d88 100644
> --- a/tools/perf/util/Build
> +++ b/tools/perf/util/Build
> @@ -121,6 +121,7 @@ perf-util-y += topdown.o
> perf-util-y += iostat.o
> perf-util-y += stream.o
> perf-util-y += kvm-stat.o
> +perf-util-y += lock-contention.o
> perf-util-$(CONFIG_AUXTRACE) += auxtrace.o
> perf-util-y += intel-pt-decoder/
> perf-util-$(CONFIG_AUXTRACE) += intel-pt.o
> diff --git a/tools/perf/util/bpf_lock_contention.c b/tools/perf/util/bpf_lock_contention.c
> index 41a1ad087895..37e17c56f106 100644
> --- a/tools/perf/util/bpf_lock_contention.c
> +++ b/tools/perf/util/bpf_lock_contention.c
> @@ -458,7 +458,7 @@ int lock_contention_read(struct lock_contention *con)
> if (con->save_callstack) {
> bpf_map_lookup_elem(stack, &key.stack_id, stack_trace);
>
> - if (!match_callstack_filter(machine, stack_trace)) {
> + if (!match_callstack_filter(machine, stack_trace, con->max_stack)) {
> con->nr_filtered += data.count;
> goto next;
> }
> diff --git a/tools/perf/util/lock-contention.c b/tools/perf/util/lock-contention.c
> new file mode 100644
> index 000000000000..841bb18b1f06
> --- /dev/null
> +++ b/tools/perf/util/lock-contention.c
> @@ -0,0 +1,170 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#include "debug.h"
> +#include "env.h"
> +#include "lock-contention.h"
> +#include "machine.h"
> +#include "symbol.h"
> +
> +#include <limits.h>
> +#include <string.h>
> +
> +#include <linux/hash.h>
> +#include <linux/zalloc.h>
> +
> +#define __lockhashfn(key) hash_long((unsigned long)key, LOCKHASH_BITS)
> +#define lockhashentry(key) (lockhash_table + __lockhashfn((key)))
> +
> +struct callstack_filter {
> + struct list_head list;
> + char name[];
> +};
> +
> +static LIST_HEAD(callstack_filters);
> +struct hlist_head *lockhash_table;
> +
> +int parse_call_stack(const struct option *opt __maybe_unused, const char *str,
> + int unset __maybe_unused)
> +{
> + char *s, *tmp, *tok;
> + int ret = 0;
> +
> + s = strdup(str);
> + if (s == NULL)
> + return -1;
> +
> + for (tok = strtok_r(s, ", ", &tmp); tok; tok = strtok_r(NULL, ", ", &tmp)) {
> + struct callstack_filter *entry;
> +
> + entry = malloc(sizeof(*entry) + strlen(tok) + 1);
> + if (entry == NULL) {
> + pr_err("Memory allocation failure\n");
> + free(s);
> + return -1;
> + }
> +
> + strcpy(entry->name, tok);
> + list_add_tail(&entry->list, &callstack_filters);
> + }
> +
> + free(s);
> + return ret;
> +}
> +
> +bool needs_callstack(void)
> +{
> + return !list_empty(&callstack_filters);
> +}
> +
> +struct lock_stat *lock_stat_find(u64 addr)
> +{
> + struct hlist_head *entry = lockhashentry(addr);
> + struct lock_stat *ret;
> +
> + hlist_for_each_entry(ret, entry, hash_entry) {
> + if (ret->addr == addr)
> + return ret;
> + }
> + return NULL;
> +}
> +
> +struct lock_stat *lock_stat_findnew(u64 addr, const char *name, int flags)
> +{
> + struct hlist_head *entry = lockhashentry(addr);
> + struct lock_stat *ret, *new;
> +
> + hlist_for_each_entry(ret, entry, hash_entry) {
> + if (ret->addr == addr)
> + return ret;
> + }
> +
> + new = zalloc(sizeof(struct lock_stat));
> + if (!new)
> + goto alloc_failed;
> +
> + new->addr = addr;
> + new->name = strdup(name);
> + if (!new->name) {
> + free(new);
> + goto alloc_failed;
> + }
> +
> + new->flags = flags;
> + new->wait_time_min = ULLONG_MAX;
> +
> + hlist_add_head(&new->hash_entry, entry);
> + return new;
> +
> +alloc_failed:
> + pr_err("memory allocation failed\n");
> + return NULL;
> +}
> +
> +bool match_callstack_filter(struct machine *machine, u64 *callstack, int max_stack_depth)
> +{
> + struct map *kmap;
> + struct symbol *sym;
> + u64 ip;
> + const char *arch = perf_env__arch(machine->env);
> +
> + if (list_empty(&callstack_filters))
> + return true;
> +
> + for (int i = 0; i < max_stack_depth; i++) {
> + struct callstack_filter *filter;
> +
> + /*
> + * In powerpc, the callchain saved by kernel always includes
> + * first three entries as the NIP (next instruction pointer),
> + * LR (link register), and the contents of LR save area in the
> + * second stack frame. In certain scenarios its possible to have
> + * invalid kernel instruction addresses in either LR or the second
> + * stack frame's LR. In that case, kernel will store that address as
> + * zero.
> + *
> + * The below check will continue to look into callstack,
> + * incase first or second callstack index entry has 0
> + * address for powerpc.
> + */
> + if (!callstack || (!callstack[i] && (strcmp(arch, "powerpc") ||
> + (i != 1 && i != 2))))
> + break;
> +
> + ip = callstack[i];
> + sym = machine__find_kernel_symbol(machine, ip, &kmap);
> + if (sym == NULL)
> + continue;
> +
> + list_for_each_entry(filter, &callstack_filters, list) {
> + if (strstr(sym->name, filter->name))
> + return true;
> + }
> + }
> + return false;
> +}
> +
> +#ifndef HAVE_BPF_SKEL
> +int lock_contention_prepare(struct lock_contention *con __maybe_unused)
> +{
> + return 0;
> +}
> +
> +int lock_contention_start(void)
> +{
> + return 0;
> +}
> +
> +int lock_contention_stop(void)
> +{
> + return 0;
> +}
> +
> +int lock_contention_finish(struct lock_contention *con __maybe_unused)
> +{
> + return 0;
> +}
> +
> +int lock_contention_read(struct lock_contention *con __maybe_unused)
> +{
> + return 0;
> +}
> +#endif /* !HAVE_BPF_SKEL */
> diff --git a/tools/perf/util/lock-contention.h b/tools/perf/util/lock-contention.h
> index 1a7248ff3889..bfa5c7db0a5d 100644
> --- a/tools/perf/util/lock-contention.h
> +++ b/tools/perf/util/lock-contention.h
> @@ -67,10 +67,11 @@ struct lock_stat {
> */
> #define MAX_LOCK_DEPTH 48
>
> -struct lock_stat *lock_stat_find(u64 addr);
> -struct lock_stat *lock_stat_findnew(u64 addr, const char *name, int flags);
> +/* based on kernel/lockdep.c */
> +#define LOCKHASH_BITS 12
> +#define LOCKHASH_SIZE (1UL << LOCKHASH_BITS)
>
> -bool match_callstack_filter(struct machine *machine, u64 *callstack);
> +extern struct hlist_head *lockhash_table;
>
> /*
> * struct lock_seq_stat:
> @@ -148,7 +149,14 @@ struct lock_contention {
> bool save_callstack;
> };
>
> -#ifdef HAVE_BPF_SKEL
> +struct option;
> +int parse_call_stack(const struct option *opt, const char *str, int unset);
> +bool needs_callstack(void);
> +
> +struct lock_stat *lock_stat_find(u64 addr);
> +struct lock_stat *lock_stat_findnew(u64 addr, const char *name, int flags);
> +
> +bool match_callstack_filter(struct machine *machine, u64 *callstack, int max_stack_depth);
>
> int lock_contention_prepare(struct lock_contention *con);
> int lock_contention_start(void);
> @@ -156,25 +164,4 @@ int lock_contention_stop(void);
> int lock_contention_read(struct lock_contention *con);
> int lock_contention_finish(struct lock_contention *con);
>
> -#else /* !HAVE_BPF_SKEL */
> -
> -static inline int lock_contention_prepare(struct lock_contention *con __maybe_unused)
> -{
> - return 0;
> -}
> -
> -static inline int lock_contention_start(void) { return 0; }
> -static inline int lock_contention_stop(void) { return 0; }
> -static inline int lock_contention_finish(struct lock_contention *con __maybe_unused)
> -{
> - return 0;
> -}
> -
> -static inline int lock_contention_read(struct lock_contention *con __maybe_unused)
> -{
> - return 0;
> -}
> -
> -#endif /* HAVE_BPF_SKEL */
> -
> #endif /* PERF_LOCK_CONTENTION_H */
> diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c
> index 35d84a96dbec..91fd444615cd 100644
> --- a/tools/perf/util/python.c
> +++ b/tools/perf/util/python.c
> @@ -18,7 +18,6 @@
> #include "mmap.h"
> #include "util/kwork.h"
> #include "util/sample.h"
> -#include "util/lock-contention.h"
> #include <internal/lib.h>
> #include "../builtin.h"
>
> @@ -1311,22 +1310,6 @@ struct kwork_work *perf_kwork_add_work(struct perf_kwork *kwork __maybe_unused,
> return NULL;
> }
>
> -bool match_callstack_filter(struct machine *machine __maybe_unused, u64 *callstack __maybe_unused)
> -{
> - return false;
> -}
> -
> -struct lock_stat *lock_stat_find(u64 addr __maybe_unused)
> -{
> - return NULL;
> -}
> -
> -struct lock_stat *lock_stat_findnew(u64 addr __maybe_unused, const char *name __maybe_unused,
> - int flags __maybe_unused)
> -{
> - return NULL;
> -}
> -
> int cmd_inject(int argc __maybe_unused, const char *argv[] __maybe_unused)
> {
> return -1;
> --
> 2.47.0.163.g1226f6d8fa-goog
>
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