[PATCH v2 17/18] perf symbol: Use session allocation wrappers in symbol, DSO, thread, and hist paths
From: Ian Rogers
Date: Tue Oct 27 2026 - 19:18:58 EST
Connect the session-scoped allocation wrappers (perf_session__malloc,
perf_session__zalloc, perf_session__calloc, perf_session__realloc,
perf_session__strdup) to the primary heap allocation paths during sample
and symbol processing: symbol__new(), symbols->symbols array growth,
dso__new_id(), thread__new(), and hist_entry allocation.
In normal operation when memory is available, behavior is unchanged.
When an allocation fails with NULL, these paths now invoke
perf_session__shrink() on the owning perf_session to reclaim
unreferenced symbols and DSOs and retry the allocation once before
failing.
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/perf/util/dso.c | 4 ++-
tools/perf/util/dsos.c | 7 +++++
tools/perf/util/hist.c | 41 +++++++++++++++++++++---
tools/perf/util/machine.c | 8 ++++-
tools/perf/util/symbol-elf.c | 14 ++++++---
tools/perf/util/symbol.c | 60 +++++++++++++++++++++++-------------
tools/perf/util/symbol.h | 3 ++
7 files changed, 104 insertions(+), 33 deletions(-)
diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index c19de9ab4b24..de694e119a6e 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -27,6 +27,7 @@
#include "map.h"
#include "namespaces.h"
#include "path.h"
+#include "session.h"
#include "srcline.h"
#include "string2.h"
#include "symbol.h"
@@ -1214,10 +1215,11 @@ static struct dso_cache *dso_cache__populate(struct dso *dso,
u64 offset, ssize_t *ret)
{
u64 cache_offset = offset & DSO__DATA_CACHE_MASK;
+ struct perf_session *session = machine ? machine__session(machine) : dso__session(dso);
struct dso_cache *cache;
struct dso_cache *old;
- cache = zalloc(sizeof(*cache) + DSO__DATA_CACHE_SIZE);
+ cache = perf_session__zalloc(session, sizeof(*cache) + DSO__DATA_CACHE_SIZE);
if (!cache) {
*ret = -ENOMEM;
return NULL;
diff --git a/tools/perf/util/dsos.c b/tools/perf/util/dsos.c
index 8f3e3f3c6ce3..374e1c5d2c32 100644
--- a/tools/perf/util/dsos.c
+++ b/tools/perf/util/dsos.c
@@ -2,6 +2,8 @@
#include "debug.h"
#include "dsos.h"
#include "dso.h"
+#include "machine.h"
+#include "session.h"
#include "util.h"
#include "vdso.h"
#include "namespaces.h"
@@ -350,6 +352,11 @@ struct dso *dsos__findnew_id(struct dsos *dsos, const char *name, const struct d
down_write(&dsos->lock);
dso = __dsos__findnew_id(dsos, name, id);
up_write(&dsos->lock);
+ if (!dso && dsos->machine && perf_session__shrink(machine__session(dsos->machine)) > 0) {
+ down_write(&dsos->lock);
+ dso = __dsos__findnew_id(dsos, name, id);
+ up_write(&dsos->lock);
+ }
return dso;
}
diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index badae244638c..4242d3f6f955 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -524,16 +524,45 @@ struct hist_entry *hists__get_entry(struct hists *hists, int idx)
* histogram, sorted on item, collects periods
*/
+static struct perf_session *hist_entry__session(const struct hist_entry *he)
+{
+ struct maps *maps;
+
+ if (!he)
+ return NULL;
+
+ if (he->ms.map) {
+ struct dso *dso = map__dso(he->ms.map);
+ struct perf_session *session = dso__session(dso);
+
+ if (session)
+ return session;
+ }
+
+ maps = he->thread ? thread__maps(he->thread) : NULL;
+ if (maps) {
+ struct machine *machine = maps__machine(maps);
+ struct perf_session *session = machine__session(machine);
+
+ if (session)
+ return session;
+ }
+
+ return NULL;
+}
+
static int hist_entry__init(struct hist_entry *he,
struct hist_entry *template,
bool sample_self,
size_t callchain_size)
{
+ struct perf_session *session = hist_entry__session(template);
+
*he = *template;
he->callchain_size = callchain_size;
if (symbol_conf.cumulate_callchain) {
- he->stat_acc = malloc(sizeof(he->stat));
+ he->stat_acc = perf_session__malloc(session, sizeof(he->stat));
if (he->stat_acc == NULL)
return -ENOMEM;
memcpy(he->stat_acc, &he->stat, sizeof(he->stat));
@@ -551,7 +580,7 @@ static int hist_entry__init(struct hist_entry *he,
* sample__resolve_bstack() and will be freed after
* adding new entries. So we need to save a copy.
*/
- he->branch_info = malloc(sizeof(*he->branch_info));
+ he->branch_info = perf_session__malloc(session, sizeof(*he->branch_info));
if (he->branch_info == NULL)
goto err;
@@ -582,14 +611,14 @@ static int hist_entry__init(struct hist_entry *he,
}
if (he->srcline && he->srcline != SRCLINE_UNKNOWN) {
- he->srcline = strdup(he->srcline);
+ he->srcline = perf_session__strdup(session, he->srcline);
if (he->srcline == NULL)
goto err_rawdata;
}
if (symbol_conf.res_sample) {
- he->res_samples = calloc(symbol_conf.res_sample,
- sizeof(struct res_sample));
+ he->res_samples = perf_session__calloc(session, symbol_conf.res_sample,
+ sizeof(struct res_sample));
if (!he->res_samples)
goto err_srcline;
}
@@ -655,6 +684,8 @@ static struct hist_entry *hist_entry__new(struct hist_entry *template,
callchain_size = sizeof(struct callchain_root);
he = ops->new(callchain_size);
+ if (!he && perf_session__shrink(hist_entry__session(template)) > 0)
+ he = ops->new(callchain_size);
if (he) {
err = hist_entry__init(he, template, sample_self, callchain_size);
if (err) {
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 3e0d68fd5efe..f45befc35a7f 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -20,6 +20,7 @@
#include "mem-events.h"
#include "mem-info.h"
#include "path.h"
+#include "session.h"
#include "srcline.h"
#include "symbol.h"
#include "synthetic-events.h"
@@ -598,7 +599,12 @@ static struct thread *__machine__findnew_thread(struct machine *machine,
struct thread *machine__findnew_thread(struct machine *machine, pid_t pid, pid_t tid)
{
- return __machine__findnew_thread(machine, pid, tid, /*create=*/true);
+ struct thread *th = __machine__findnew_thread(machine, pid, tid, /*create=*/true);
+
+ if (!th && perf_session__shrink(machine__session(machine)) > 0)
+ th = __machine__findnew_thread(machine, pid, tid, /*create=*/true);
+
+ return th;
}
struct thread *machine__find_thread(struct machine *machine, pid_t pid,
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 946a2426933c..75139fab0748 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -15,6 +15,7 @@
#include "symbol.h"
#include "symsrc.h"
#include "machine.h"
+#include "session.h"
#include "vdso.h"
#include "debug.h"
#include "util/copyfile.h"
@@ -701,7 +702,7 @@ static int dso__synthesize_plt_got_symbols(struct dso *dso, Elf *elf,
sym = symbol__new(shdr.sh_offset + i, shdr.sh_entsize, STB_GLOBAL, STT_FUNC, buf);
if (!sym)
goto out;
- if (symbols__insert(dso__symbols(dso), sym))
+ if (symbols__insert_session(dso__symbols(dso), sym, dso__session(dso)))
goto out;
}
err = 0;
@@ -757,7 +758,7 @@ int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss)
plt_sym = symbol__new(shdr_plt.sh_offset, plt_header_size, STB_GLOBAL, STT_FUNC, ".plt");
if (!plt_sym)
goto out_elf_end;
- if (symbols__insert(dso__symbols(dso), plt_sym))
+ if (symbols__insert_session(dso__symbols(dso), plt_sym, dso__session(dso)))
goto out_elf_end;
/* Only x86 has .plt.got */
@@ -880,7 +881,7 @@ int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss)
goto out_elf_end;
plt_offset += plt_entry_size;
- if (symbols__insert(dso__symbols(dso), f))
+ if (symbols__insert_session(dso__symbols(dso), f, dso__session(dso)))
goto out_elf_end;
++nr;
}
@@ -1939,13 +1940,18 @@ dso__load_sym_internal(struct dso *dso, struct map *map, struct symsrc *syms_ss,
f = symbol__new(sym.st_value, sym.st_size,
GELF_ST_BIND(sym.st_info),
GELF_ST_TYPE(sym.st_info), elf_name);
+ if (!f && perf_session__shrink(dso__session(curr_dso)) > 0) {
+ f = symbol__new(sym.st_value, sym.st_size,
+ GELF_ST_BIND(sym.st_info),
+ GELF_ST_TYPE(sym.st_info), elf_name);
+ }
free(demangled);
if (!f)
goto out_elf_end;
arch__sym_update(f, &sym);
- if (symbols__insert(dso__symbols(curr_dso), f))
+ if (symbols__insert_session(dso__symbols(curr_dso), f, dso__session(curr_dso)))
goto out_elf_end;
nr++;
}
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index e5338c8e03dc..6bba489ff535 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -41,6 +41,7 @@
#include "namespaces.h"
#include "header.h"
#include "path.h"
+#include "session.h"
#include <linux/ctype.h>
#include <linux/log2.h>
#include <linux/zalloc.h>
@@ -938,12 +939,13 @@ static void symbol__set_idle(struct symbol *sym, bool idle)
} while (!atomic_compare_exchange_weak(&RC_CHK_ACCESS(sym)->flags, &old_flags, new_flags));
}
-static int __symbols__insert(struct symbols *symbols, struct symbol *sym)
+static int __symbols__insert(struct symbols *symbols, struct symbol *sym,
+ struct perf_session *session)
{
if (symbols->cnt == symbols->allocated) {
unsigned int to_allocate = symbols->allocated ? symbols->allocated * 2 : 32;
- struct symbol **temp = realloc(symbols->symbols,
- sizeof(struct symbol *) * to_allocate);
+ struct symbol **temp = perf_session__realloc(session, symbols->symbols,
+ sizeof(struct symbol *) * to_allocate);
if (!temp) {
symbol__put(sym);
@@ -1008,7 +1010,8 @@ static void symbols__restore_retained(struct symbols *symbols,
static void symbols__merge_retained(struct symbols *symbols,
struct symbol **retained,
- unsigned int retained_cnt)
+ unsigned int retained_cnt,
+ struct perf_session *session)
{
unsigned int fresh_cnt;
bool need_sort = false;
@@ -1064,7 +1067,7 @@ static void symbols__merge_retained(struct symbols *symbols,
symbol__set_ifunc_alias(ret_sym, true);
symbols->symbols[match_idx] = ret_sym;
symbol__put(fresh_sym);
- } else if (__symbols__insert(symbols, ret_sym) == 0) {
+ } else if (__symbols__insert(symbols, ret_sym, session) == 0) {
need_sort = true;
}
}
@@ -1080,17 +1083,18 @@ static void symbols__merge_retained(struct symbols *symbols,
free(retained);
}
-static int __symbols__insert_sorted(struct symbols *symbols, struct symbol *sym)
+static int __symbols__insert_sorted(struct symbols *symbols, struct symbol *sym,
+ struct perf_session *session)
{
unsigned int idx;
if (!symbols->sorted)
- return __symbols__insert(symbols, sym);
+ return __symbols__insert(symbols, sym, session);
if (symbols->cnt == symbols->allocated) {
unsigned int to_allocate = symbols->allocated ? symbols->allocated * 2 : 32;
- struct symbol **temp = realloc(symbols->symbols,
- sizeof(struct symbol *) * to_allocate);
+ struct symbol **temp = perf_session__realloc(session, symbols->symbols,
+ sizeof(struct symbol *) * to_allocate);
if (!temp) {
symbol__put(sym);
@@ -1118,16 +1122,22 @@ static int __symbols__insert_sorted(struct symbols *symbols, struct symbol *sym)
return 0;
}
-int symbols__insert(struct symbols *symbols, struct symbol *sym)
+int symbols__insert_session(struct symbols *symbols, struct symbol *sym,
+ struct perf_session *session)
{
int ret;
down_write(&symbols->lock);
- ret = __symbols__insert(symbols, sym);
+ ret = __symbols__insert(symbols, sym, session);
up_write(&symbols->lock);
return ret;
}
+int symbols__insert(struct symbols *symbols, struct symbol *sym)
+{
+ return symbols__insert_session(symbols, sym, NULL);
+}
+
/*
* Binary search @symbols->symbols for a symbol covering @ip. Lazily sorts
* @symbols under @symbols->lock if unsorted.
@@ -1288,7 +1298,7 @@ int dso__insert_symbol(struct dso *dso, struct symbol *sym)
int ret;
down_write(&symbols->lock);
- ret = __symbols__insert_sorted(symbols, sym);
+ ret = __symbols__insert_sorted(symbols, sym, dso__session(dso));
up_write(&symbols->lock);
return ret;
}
@@ -1633,7 +1643,7 @@ static int map__process_kallsym_symbol(void *arg, const char *name,
* We will pass the symbols to the filter later, in
* map__split_kallsyms, when we have split the maps per module
*/
- return symbols__insert(root, sym);
+ return symbols__insert_session(root, sym, dso__session(dso));
}
/*
@@ -1697,7 +1707,8 @@ static int maps__split_kallsyms_for_kcore(struct maps *kmaps, struct dso *dso)
symbol__set_end(pos, symbol__end(pos) -
(map__start(curr_map) - map__pgoff(curr_map)));
}
- if (symbols__insert(dso__symbols(curr_map_dso), pos) == 0)
+ if (symbols__insert_session(dso__symbols(curr_map_dso), pos,
+ dso__session(curr_map_dso)) == 0)
++count;
map__put(curr_map);
}
@@ -1873,7 +1884,8 @@ static int maps__split_kallsyms(struct maps *kmaps, struct dso *dso, u64 delta,
if (!RC_CHK_EQUAL(curr_map, initial_map)) {
struct dso *curr_map_dso = map__dso(curr_map);
- if (symbols__insert(dso__symbols(curr_map_dso), pos) == 0)
+ if (symbols__insert_session(dso__symbols(curr_map_dso), pos,
+ dso__session(curr_map_dso)) == 0)
++moved;
} else {
old_symbols[write_idx++] = pos;
@@ -1895,7 +1907,7 @@ static int maps__split_kallsyms(struct maps *kmaps, struct dso *dso, u64 delta,
old_symbols = NULL;
} else {
for (unsigned int j = 0; j < write_idx; j++)
- __symbols__insert(root, old_symbols[j]);
+ __symbols__insert(root, old_symbols[j], dso__session(dso));
}
zfree(&root->symbols_by_name);
root->num_by_name = 0;
@@ -1926,7 +1938,7 @@ static int maps__split_kallsyms(struct maps *kmaps, struct dso *dso, u64 delta,
old_symbols = NULL;
} else {
for (unsigned int j = 0; j < write_idx; j++)
- __symbols__insert(root, old_symbols[j]);
+ __symbols__insert(root, old_symbols[j], dso__session(dso));
root->sorted_cnt = 0;
root->sorted = false;
}
@@ -2497,7 +2509,7 @@ static int dso__load_perf_map(const char *map_path, struct dso *dso)
if (sym == NULL)
goto out_delete_line;
- if (symbols__insert(dso__symbols(dso), sym))
+ if (symbols__insert_session(dso__symbols(dso), sym, dso__session(dso)))
goto out_delete_line;
nr_syms++;
}
@@ -2674,7 +2686,7 @@ int dso__load(struct dso *dso, struct map *map)
if (machine)
root_dir = machine->root_dir;
- name = malloc(PATH_MAX);
+ name = perf_session__malloc(dso__session(dso), PATH_MAX);
if (!name)
goto out;
@@ -2750,8 +2762,11 @@ int dso__load(struct dso *dso, struct map *map)
if (!syms_ss && symsrc__has_symtab(ss)) {
syms_ss = ss;
next_slot = true;
- if (!dso__symsrc_filename(dso))
- dso__set_symsrc_filename(dso, strdup(name));
+ if (!dso__symsrc_filename(dso)) {
+ dso__set_symsrc_filename(dso,
+ perf_session__strdup(dso__session(dso),
+ name));
+ }
}
if (!runtime_ss && symsrc__possibly_runtime(ss)) {
@@ -2805,7 +2820,8 @@ int dso__load(struct dso *dso, struct map *map)
out:
if (was_shrunk) {
if (ret > 0) {
- symbols__merge_retained(dso__symbols(dso), retained, retained_cnt);
+ symbols__merge_retained(dso__symbols(dso), retained, retained_cnt,
+ dso__session(dso));
} else {
dso__set_adjust_symbols(dso, saved_adjust_symbols);
symbols__restore_retained(dso__symbols(dso), retained,
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index 7d6469d6a976..2db5eb84b268 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -33,6 +33,7 @@ struct maps;
struct option;
struct build_id;
struct perf_env;
+struct perf_session;
/*
* Ignore kernel mapping symbols, matching kernel is_mapping_symbol() logic.
@@ -376,6 +377,8 @@ int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss);
char *dso__demangle_sym(struct dso *dso, int kmodule, const char *elf_name);
int symbols__insert(struct symbols *symbols, struct symbol *sym);
+int symbols__insert_session(struct symbols *symbols, struct symbol *sym,
+ struct perf_session *session);
void symbols__fixup_duplicate(struct symbols *symbols);
void symbols__fixup_end(struct symbols *symbols, bool is_kallsyms);
--
2.56.0.313.g2479322e68-goog