From d6cd7c9f0239b28652a7ca1870707f5ca6c49c9f Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Fri, 21 Feb 2025 22:10:09 -0800 Subject: [PATCH] perf header: Switch mem topology to io_dir__readdir Switch memory_node__read and build_mem_topology from opendir/readdir to io_dir__readdir, with smaller stack allocations. Reduces peak memory consumption of perf record by 10kb. Signed-off-by: Ian Rogers Link: https://lore.kernel.org/r/20250222061015.303622-5-irogers@google.com Signed-off-by: Namhyung Kim --- tools/perf/util/header.c | 31 ++++++++++++++++--------------- 1 file changed, 16 insertions(+), 15 deletions(-) diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index d06aa86352d3..1900965f8752 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -44,6 +44,7 @@ #include "build-id.h" #include "data.h" #include +#include #include "asm/bug.h" #include "tool.h" #include "time-utils.h" @@ -1311,11 +1312,11 @@ static int memory_node__read(struct memory_node *n, unsigned long idx) { unsigned int phys, size = 0; char path[PATH_MAX]; - struct dirent *ent; - DIR *dir; + struct io_dirent64 *ent; + struct io_dir dir; #define for_each_memory(mem, dir) \ - while ((ent = readdir(dir))) \ + while ((ent = io_dir__readdir(&dir)) != NULL) \ if (strcmp(ent->d_name, ".") && \ strcmp(ent->d_name, "..") && \ sscanf(ent->d_name, "memory%u", &mem) == 1) @@ -1324,9 +1325,9 @@ static int memory_node__read(struct memory_node *n, unsigned long idx) "%s/devices/system/node/node%lu", sysfs__mountpoint(), idx); - dir = opendir(path); - if (!dir) { - pr_warning("failed: can't open memory sysfs data\n"); + io_dir__init(&dir, open(path, O_CLOEXEC | O_DIRECTORY | O_RDONLY)); + if (dir.dirfd < 0) { + pr_warning("failed: can't open memory sysfs data '%s'\n", path); return -1; } @@ -1338,20 +1339,20 @@ static int memory_node__read(struct memory_node *n, unsigned long idx) n->set = bitmap_zalloc(size); if (!n->set) { - closedir(dir); + close(dir.dirfd); return -ENOMEM; } n->node = idx; n->size = size; - rewinddir(dir); + io_dir__rewinddir(&dir); for_each_memory(phys, dir) { __set_bit(phys, n->set); } - closedir(dir); + close(dir.dirfd); return 0; } @@ -1374,8 +1375,8 @@ static int memory_node__sort(const void *a, const void *b) static int build_mem_topology(struct memory_node **nodesp, u64 *cntp) { char path[PATH_MAX]; - struct dirent *ent; - DIR *dir; + struct io_dirent64 *ent; + struct io_dir dir; int ret = 0; size_t cnt = 0, size = 0; struct memory_node *nodes = NULL; @@ -1383,14 +1384,14 @@ static int build_mem_topology(struct memory_node **nodesp, u64 *cntp) scnprintf(path, PATH_MAX, "%s/devices/system/node/", sysfs__mountpoint()); - dir = opendir(path); - if (!dir) { + io_dir__init(&dir, open(path, O_CLOEXEC | O_DIRECTORY | O_RDONLY)); + if (dir.dirfd < 0) { pr_debug2("%s: couldn't read %s, does this arch have topology information?\n", __func__, path); return -1; } - while (!ret && (ent = readdir(dir))) { + while (!ret && (ent = io_dir__readdir(&dir))) { unsigned int idx; int r; @@ -1419,7 +1420,7 @@ static int build_mem_topology(struct memory_node **nodesp, u64 *cntp) cnt += 1; } out: - closedir(dir); + close(dir.dirfd); if (!ret) { *cntp = cnt; *nodesp = nodes; -- 2.50.1