Re: [PATCH 1/6] perf kmem: Implement stat --page --caller

From: Arnaldo Carvalho de Melo
Date: Mon May 04 2015 - 16:55:54 EST


Em Tue, Apr 21, 2015 at 01:55:02PM +0900, Namhyung Kim escreveu:
> It perf kmem support caller statistics for page. Unlike slab case,
> the tracepoints in page allocator don't provide callsite info. So
> it records with callchain and extracts callsite info.
>
> Note that the callchain contains several memory allocation functions
> which has no meaning for users. So skip those functions to get proper
> callsites. I used following regex pattern to skip the allocator
> functions:
>
> ^_?_?(alloc|get_free|get_zeroed)_pages?
>
> This gave me a following list of functions:
>
> # perf kmem record --page sleep 3
> # perf kmem stat --page -v
> ...
> alloc func: __get_free_pages
> alloc func: get_zeroed_page
> alloc func: alloc_pages_exact
> alloc func: __alloc_pages_direct_compact
> alloc func: __alloc_pages_nodemask
> alloc func: alloc_page_interleave
> alloc func: alloc_pages_current
> alloc func: alloc_pages_vma
> alloc func: alloc_page_buffers
> alloc func: alloc_pages_exact_nid
...
>
> The output looks mostly same as --alloc (I also added callsite column

> to that) but groups entries by callsite. Currently, the order,
> migrate type and GFP flag info is for the last allocation and not
> guaranteed to be same for all allocations from the callsite.

In my testing:

[root@ssdandy ~]# perf kmem stat --page --caller

------------------------------------------------------------------------------
TotalAlloc(KB)|Hits|Ord| Mig.type |GFP flags| Callsite
------------------------------------------------------------------------------
492 | 21 | 3 | UNMOVABL | 0235200 | new_slab
456 |114 | 0 | UNMOVABL | 00202d0 | iwl_pcie_rx_replenish
60 | 15 | 0 | UNMOVABL | 02284d0 | pte_alloc_one
44 | 11 | 0 | MOVABLE | 00280da | handle_mm_fault
28 | 7 | 0 | MOVABLE | 00200da | do_wp_page
16 | 4 | 0 | UNMOVABL | 00284d0 | __pmd_alloc
16 | 4 | 0 | UNMOVABL | 0020200 | __tlb_remove_page
12 | 3 | 0 | MOVABLE | 00200da | handle_mm_fault
8 | 2 | 0 | UNMOVABL | 00284d0 | __pud_alloc
4 | 1 | 0 | UNMOVABL | 0020250 | ftrace_define_fields_xfs_ag_class
4 | 1 | 0 | UNMOVABL | 0020010 | bio_copy_kern
4 | 1 | 0 | UNMOVABL | 00200d0 | __pollwait
4 | 1 | 0 | UNMOVABL | 00200d2 | pipe_write
4 | 1 | 0 | MOVABLE | 00280da | do_wp_page
4 | 1 | 0 | UNMOVABL | 02284d0 | pgd_alloc
---------------------------------------------------------------------------------

Probably that new_slab() one should go into the regexp?

[acme@ssdandy linux]$ uname -a
Linux ssdandy 4.0.0-rc6+ #3 SMP Mon Apr 13 16:45:57 BRT 2015 x86_64 x86_64 x86_64 GNU/Linux

[acme@ssdandy linux]$ grep SL.B /lib/modules/`uname -r`/build/.config
CONFIG_SLUB_DEBUG=y
# CONFIG_SLAB is not set
CONFIG_SLUB=y
CONFIG_SLUB_CPU_PARTIAL=y
CONFIG_SLABINFO=y
# CONFIG_SLUB_DEBUG_ON is not set
# CONFIG_SLUB_STATS is not set
[acme@ssdandy linux]$

- Arnaldo

> ---------------------------------------------------------------------------------------------
> Total_alloc (KB) | Hits | Order | Mig.type | GFP flags | Callsite
> ---------------------------------------------------------------------------------------------
> 1,064 | 266 | 0 | UNMOVABL | 000000d0 | __pollwait
> 52 | 13 | 0 | UNMOVABL | 002084d0 | pte_alloc_one
> 44 | 11 | 0 | MOVABLE | 000280da | handle_mm_fault
> 20 | 5 | 0 | MOVABLE | 000200da | do_cow_fault
> 20 | 5 | 0 | MOVABLE | 000200da | do_wp_page
> 16 | 4 | 0 | UNMOVABL | 000084d0 | __pmd_alloc
> 16 | 4 | 0 | UNMOVABL | 00000200 | __tlb_remove_page
> 12 | 3 | 0 | UNMOVABL | 000084d0 | __pud_alloc
> 8 | 2 | 0 | UNMOVABL | 00000010 | bio_copy_user_iov
> 4 | 1 | 0 | UNMOVABL | 000200d2 | pipe_write
> 4 | 1 | 0 | MOVABLE | 000280da | do_wp_page
> 4 | 1 | 0 | UNMOVABL | 002084d0 | pgd_alloc
> ---------------------------------------------------------------------------------------------
>
> Acked-by: Pekka Enberg <penberg@xxxxxxxxxx>
> Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
> ---
> tools/perf/builtin-kmem.c | 327 +++++++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 306 insertions(+), 21 deletions(-)
>
> diff --git a/tools/perf/builtin-kmem.c b/tools/perf/builtin-kmem.c
> index 4f0f38462d97..3649eec6807f 100644
> --- a/tools/perf/builtin-kmem.c
> +++ b/tools/perf/builtin-kmem.c
> @@ -10,6 +10,7 @@
> #include "util/header.h"
> #include "util/session.h"
> #include "util/tool.h"
> +#include "util/callchain.h"
>
> #include "util/parse-options.h"
> #include "util/trace-event.h"
> @@ -21,6 +22,7 @@
> #include <linux/rbtree.h>
> #include <linux/string.h>
> #include <locale.h>
> +#include <regex.h>
>
> static int kmem_slab;
> static int kmem_page;
> @@ -241,6 +243,7 @@ static unsigned long nr_page_fails;
> static unsigned long nr_page_nomatch;
>
> static bool use_pfn;
> +static struct perf_session *kmem_session;
>
> #define MAX_MIGRATE_TYPES 6
> #define MAX_PAGE_ORDER 11
> @@ -250,6 +253,7 @@ static int order_stats[MAX_PAGE_ORDER][MAX_MIGRATE_TYPES];
> struct page_stat {
> struct rb_node node;
> u64 page;
> + u64 callsite;
> int order;
> unsigned gfp_flags;
> unsigned migrate_type;
> @@ -262,8 +266,144 @@ struct page_stat {
> static struct rb_root page_tree;
> static struct rb_root page_alloc_tree;
> static struct rb_root page_alloc_sorted;
> +static struct rb_root page_caller_tree;
> +static struct rb_root page_caller_sorted;
>
> -static struct page_stat *search_page(unsigned long page, bool create)
> +struct alloc_func {
> + u64 start;
> + u64 end;
> + char *name;
> +};
> +
> +static int nr_alloc_funcs;
> +static struct alloc_func *alloc_func_list;
> +
> +static int funcmp(const void *a, const void *b)
> +{
> + const struct alloc_func *fa = a;
> + const struct alloc_func *fb = b;
> +
> + if (fa->start > fb->start)
> + return 1;
> + else
> + return -1;
> +}
> +
> +static int callcmp(const void *a, const void *b)
> +{
> + const struct alloc_func *fa = a;
> + const struct alloc_func *fb = b;
> +
> + if (fb->start <= fa->start && fa->end < fb->end)
> + return 0;
> +
> + if (fa->start > fb->start)
> + return 1;
> + else
> + return -1;
> +}
> +
> +static int build_alloc_func_list(void)
> +{
> + int ret;
> + struct map *kernel_map;
> + struct symbol *sym;
> + struct rb_node *node;
> + struct alloc_func *func;
> + struct machine *machine = &kmem_session->machines.host;
> + regex_t alloc_func_regex;
> + const char pattern[] = "^_?_?(alloc|get_free|get_zeroed)_pages?";
> +
> + ret = regcomp(&alloc_func_regex, pattern, REG_EXTENDED);
> + if (ret) {
> + char err[BUFSIZ];
> +
> + regerror(ret, &alloc_func_regex, err, sizeof(err));
> + pr_err("Invalid regex: %s\n%s", pattern, err);
> + return -EINVAL;
> + }
> +
> + kernel_map = machine->vmlinux_maps[MAP__FUNCTION];
> + if (map__load(kernel_map, NULL) < 0) {
> + pr_err("cannot load kernel map\n");
> + return -ENOENT;
> + }
> +
> + map__for_each_symbol(kernel_map, sym, node) {
> + if (regexec(&alloc_func_regex, sym->name, 0, NULL, 0))
> + continue;
> +
> + func = realloc(alloc_func_list,
> + (nr_alloc_funcs + 1) * sizeof(*func));
> + if (func == NULL)
> + return -ENOMEM;
> +
> + pr_debug("alloc func: %s\n", sym->name);
> + func[nr_alloc_funcs].start = sym->start;
> + func[nr_alloc_funcs].end = sym->end;
> + func[nr_alloc_funcs].name = sym->name;
> +
> + alloc_func_list = func;
> + nr_alloc_funcs++;
> + }
> +
> + qsort(alloc_func_list, nr_alloc_funcs, sizeof(*func), funcmp);
> +
> + regfree(&alloc_func_regex);
> + return 0;
> +}
> +
> +/*
> + * Find first non-memory allocation function from callchain.
> + * The allocation functions are in the 'alloc_func_list'.
> + */
> +static u64 find_callsite(struct perf_evsel *evsel, struct perf_sample *sample)
> +{
> + struct addr_location al;
> + struct machine *machine = &kmem_session->machines.host;
> + struct callchain_cursor_node *node;
> +
> + if (alloc_func_list == NULL) {
> + if (build_alloc_func_list() < 0)
> + goto out;
> + }
> +
> + al.thread = machine__findnew_thread(machine, sample->pid, sample->tid);
> + sample__resolve_callchain(sample, NULL, evsel, &al, 16);
> +
> + callchain_cursor_commit(&callchain_cursor);
> + while (true) {
> + struct alloc_func key, *caller;
> + u64 addr;
> +
> + node = callchain_cursor_current(&callchain_cursor);
> + if (node == NULL)
> + break;
> +
> + key.start = key.end = node->ip;
> + caller = bsearch(&key, alloc_func_list, nr_alloc_funcs,
> + sizeof(key), callcmp);
> + if (!caller) {
> + /* found */
> + if (node->map)
> + addr = map__unmap_ip(node->map, node->ip);
> + else
> + addr = node->ip;
> +
> + return addr;
> + } else
> + pr_debug3("skipping alloc function: %s\n", caller->name);
> +
> + callchain_cursor_advance(&callchain_cursor);
> + }
> +
> +out:
> + pr_debug2("unknown callsite: %"PRIx64 "\n", sample->ip);
> + return sample->ip;
> +}
> +
> +static struct page_stat *
> +__page_stat__findnew_page(u64 page, bool create)
> {
> struct rb_node **node = &page_tree.rb_node;
> struct rb_node *parent = NULL;
> @@ -298,6 +438,16 @@ static struct page_stat *search_page(unsigned long page, bool create)
> return data;
> }
>
> +static struct page_stat *page_stat__find_page(u64 page)
> +{
> + return __page_stat__findnew_page(page, false);
> +}
> +
> +static struct page_stat *page_stat__findnew_page(u64 page)
> +{
> + return __page_stat__findnew_page(page, true);
> +}
> +
> static int page_stat_cmp(struct page_stat *a, struct page_stat *b)
> {
> if (a->page > b->page)
> @@ -319,7 +469,8 @@ static int page_stat_cmp(struct page_stat *a, struct page_stat *b)
> return 0;
> }
>
> -static struct page_stat *search_page_alloc_stat(struct page_stat *pstat, bool create)
> +static struct page_stat *
> +__page_stat__findnew_alloc(struct page_stat *pstat, bool create)
> {
> struct rb_node **node = &page_alloc_tree.rb_node;
> struct rb_node *parent = NULL;
> @@ -357,6 +508,62 @@ static struct page_stat *search_page_alloc_stat(struct page_stat *pstat, bool cr
> return data;
> }
>
> +static struct page_stat *page_stat__find_alloc(struct page_stat *pstat)
> +{
> + return __page_stat__findnew_alloc(pstat, false);
> +}
> +
> +static struct page_stat *page_stat__findnew_alloc(struct page_stat *pstat)
> +{
> + return __page_stat__findnew_alloc(pstat, true);
> +}
> +
> +static struct page_stat *
> +__page_stat__findnew_caller(u64 callsite, bool create)
> +{
> + struct rb_node **node = &page_caller_tree.rb_node;
> + struct rb_node *parent = NULL;
> + struct page_stat *data;
> +
> + while (*node) {
> + s64 cmp;
> +
> + parent = *node;
> + data = rb_entry(*node, struct page_stat, node);
> +
> + cmp = data->callsite - callsite;
> + if (cmp < 0)
> + node = &parent->rb_left;
> + else if (cmp > 0)
> + node = &parent->rb_right;
> + else
> + return data;
> + }
> +
> + if (!create)
> + return NULL;
> +
> + data = zalloc(sizeof(*data));
> + if (data != NULL) {
> + data->callsite = callsite;
> +
> + rb_link_node(&data->node, parent, node);
> + rb_insert_color(&data->node, &page_caller_tree);
> + }
> +
> + return data;
> +}
> +
> +static struct page_stat *page_stat__find_caller(u64 callsite)
> +{
> + return __page_stat__findnew_caller(callsite, false);
> +}
> +
> +static struct page_stat *page_stat__findnew_caller(u64 callsite)
> +{
> + return __page_stat__findnew_caller(callsite, true);
> +}
> +
> static bool valid_page(u64 pfn_or_page)
> {
> if (use_pfn && pfn_or_page == -1UL)
> @@ -375,6 +582,7 @@ static int perf_evsel__process_page_alloc_event(struct perf_evsel *evsel,
> unsigned int migrate_type = perf_evsel__intval(evsel, sample,
> "migratetype");
> u64 bytes = kmem_page_size << order;
> + u64 callsite;
> struct page_stat *pstat;
> struct page_stat this = {
> .order = order,
> @@ -397,25 +605,40 @@ static int perf_evsel__process_page_alloc_event(struct perf_evsel *evsel,
> return 0;
> }
>
> + callsite = find_callsite(evsel, sample);
> +
> /*
> * This is to find the current page (with correct gfp flags and
> * migrate type) at free event.
> */
> - pstat = search_page(page, true);
> + pstat = page_stat__findnew_page(page);
> if (pstat == NULL)
> return -ENOMEM;
>
> pstat->order = order;
> pstat->gfp_flags = gfp_flags;
> pstat->migrate_type = migrate_type;
> + pstat->callsite = callsite;
>
> this.page = page;
> - pstat = search_page_alloc_stat(&this, true);
> + pstat = page_stat__findnew_alloc(&this);
> if (pstat == NULL)
> return -ENOMEM;
>
> pstat->nr_alloc++;
> pstat->alloc_bytes += bytes;
> + pstat->callsite = callsite;
> +
> + pstat = page_stat__findnew_caller(callsite);
> + if (pstat == NULL)
> + return -ENOMEM;
> +
> + pstat->order = order;
> + pstat->gfp_flags = gfp_flags;
> + pstat->migrate_type = migrate_type;
> +
> + pstat->nr_alloc++;
> + pstat->alloc_bytes += bytes;
>
> order_stats[order][migrate_type]++;
>
> @@ -441,7 +664,7 @@ static int perf_evsel__process_page_free_event(struct perf_evsel *evsel,
> nr_page_frees++;
> total_page_free_bytes += bytes;
>
> - pstat = search_page(page, false);
> + pstat = page_stat__find_page(page);
> if (pstat == NULL) {
> pr_debug2("missing free at page %"PRIx64" (order: %d)\n",
> page, order);
> @@ -455,11 +678,19 @@ static int perf_evsel__process_page_free_event(struct perf_evsel *evsel,
> this.page = page;
> this.gfp_flags = pstat->gfp_flags;
> this.migrate_type = pstat->migrate_type;
> + this.callsite = pstat->callsite;
>
> rb_erase(&pstat->node, &page_tree);
> free(pstat);
>
> - pstat = search_page_alloc_stat(&this, false);
> + pstat = page_stat__find_alloc(&this);
> + if (pstat == NULL)
> + return -ENOENT;
> +
> + pstat->nr_free++;
> + pstat->free_bytes += bytes;
> +
> + pstat = page_stat__find_caller(this.callsite);
> if (pstat == NULL)
> return -ENOENT;
>
> @@ -576,41 +807,89 @@ static const char * const migrate_type_str[] = {
> "UNKNOWN",
> };
>
> -static void __print_page_result(struct rb_root *root,
> - struct perf_session *session __maybe_unused,
> - int n_lines)
> +static void __print_page_alloc_result(struct perf_session *session, int n_lines)
> {
> - struct rb_node *next = rb_first(root);
> + struct rb_node *next = rb_first(&page_alloc_sorted);
> + struct machine *machine = &session->machines.host;
> const char *format;
>
> - printf("\n%.80s\n", graph_dotted_line);
> - printf(" %-16s | Total alloc (KB) | Hits | Order | Mig.type | GFP flags\n",
> + printf("\n%.105s\n", graph_dotted_line);
> + printf(" %-16s | Total alloc (KB) | Hits | Order | Mig.type | GFP flags | Callsite\n",
> use_pfn ? "PFN" : "Page");
> - printf("%.80s\n", graph_dotted_line);
> + printf("%.105s\n", graph_dotted_line);
>
> if (use_pfn)
> - format = " %16llu | %'16llu | %'9d | %5d | %8s | %08lx\n";
> + format = " %16llu | %'16llu | %'9d | %5d | %8s | %08lx | %s\n";
> else
> - format = " %016llx | %'16llu | %'9d | %5d | %8s | %08lx\n";
> + format = " %016llx | %'16llu | %'9d | %5d | %8s | %08lx | %s\n";
>
> while (next && n_lines--) {
> struct page_stat *data;
> + struct symbol *sym;
> + struct map *map;
> + char buf[32];
> + char *caller = buf;
>
> data = rb_entry(next, struct page_stat, node);
> + sym = machine__find_kernel_function(machine, data->callsite,
> + &map, NULL);
> + if (sym && sym->name)
> + caller = sym->name;
> + else
> + scnprintf(buf, sizeof(buf), "%"PRIx64, data->callsite);
>
> printf(format, (unsigned long long)data->page,
> (unsigned long long)data->alloc_bytes / 1024,
> data->nr_alloc, data->order,
> migrate_type_str[data->migrate_type],
> - (unsigned long)data->gfp_flags);
> + (unsigned long)data->gfp_flags, caller);
>
> next = rb_next(next);
> }
>
> if (n_lines == -1)
> - printf(" ... | ... | ... | ... | ... | ... \n");
> + printf(" ... | ... | ... | ... | ... | ... | ...\n");
>
> - printf("%.80s\n", graph_dotted_line);
> + printf("%.105s\n", graph_dotted_line);
> +}
> +
> +static void __print_page_caller_result(struct perf_session *session, int n_lines)
> +{
> + struct rb_node *next = rb_first(&page_caller_sorted);
> + struct machine *machine = &session->machines.host;
> +
> + printf("\n%.105s\n", graph_dotted_line);
> + printf(" Total alloc (KB) | Hits | Order | Mig.type | GFP flags | Callsite\n");
> + printf("%.105s\n", graph_dotted_line);
> +
> + while (next && n_lines--) {
> + struct page_stat *data;
> + struct symbol *sym;
> + struct map *map;
> + char buf[32];
> + char *caller = buf;
> +
> + data = rb_entry(next, struct page_stat, node);
> + sym = machine__find_kernel_function(machine, data->callsite,
> + &map, NULL);
> + if (sym && sym->name)
> + caller = sym->name;
> + else
> + scnprintf(buf, sizeof(buf), "%"PRIx64, data->callsite);
> +
> + printf(" %'16llu | %'9d | %5d | %8s | %08lx | %s\n",
> + (unsigned long long)data->alloc_bytes / 1024,
> + data->nr_alloc, data->order,
> + migrate_type_str[data->migrate_type],
> + (unsigned long)data->gfp_flags, caller);
> +
> + next = rb_next(next);
> + }
> +
> + if (n_lines == -1)
> + printf(" ... | ... | ... | ... | ... | ...\n");
> +
> + printf("%.105s\n", graph_dotted_line);
> }
>
> static void print_slab_summary(void)
> @@ -682,8 +961,10 @@ static void print_slab_result(struct perf_session *session)
>
> static void print_page_result(struct perf_session *session)
> {
> + if (caller_flag)
> + __print_page_caller_result(session, caller_lines);
> if (alloc_flag)
> - __print_page_result(&page_alloc_sorted, session, alloc_lines);
> + __print_page_alloc_result(session, alloc_lines);
> print_page_summary();
> }
>
> @@ -802,6 +1083,7 @@ static void sort_result(void)
> }
> if (kmem_page) {
> __sort_page_result(&page_alloc_tree, &page_alloc_sorted);
> + __sort_page_result(&page_caller_tree, &page_caller_sorted);
> }
> }
>
> @@ -1084,7 +1366,7 @@ static int __cmd_record(int argc, const char **argv)
> if (kmem_slab)
> rec_argc += ARRAY_SIZE(slab_events);
> if (kmem_page)
> - rec_argc += ARRAY_SIZE(page_events);
> + rec_argc += ARRAY_SIZE(page_events) + 1; /* for -g */
>
> rec_argv = calloc(rec_argc + 1, sizeof(char *));
>
> @@ -1099,6 +1381,8 @@ static int __cmd_record(int argc, const char **argv)
> rec_argv[i] = strdup(slab_events[j]);
> }
> if (kmem_page) {
> + rec_argv[i++] = strdup("-g");
> +
> for (j = 0; j < ARRAY_SIZE(page_events); j++, i++)
> rec_argv[i] = strdup(page_events[j]);
> }
> @@ -1159,7 +1443,7 @@ int cmd_kmem(int argc, const char **argv, const char *prefix __maybe_unused)
>
> file.path = input_name;
>
> - session = perf_session__new(&file, false, &perf_kmem);
> + kmem_session = session = perf_session__new(&file, false, &perf_kmem);
> if (session == NULL)
> return -1;
>
> @@ -1172,6 +1456,7 @@ int cmd_kmem(int argc, const char **argv, const char *prefix __maybe_unused)
> }
>
> kmem_page_size = pevent_get_page_size(evsel->tp_format->pevent);
> + symbol_conf.use_callchain = true;
> }
>
> symbol__init(&session->header.env);
> --
> 2.3.4
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/