From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Example usage:
$ pahole --padding_ge 4 --with_flexible_array
<SNIP>
struct netprio_map {
struct callback_head rcu; /* 0 16 */
u32 priomap_len; /* 16 4 */
u32 priomap[]; /* 20 0 */
/* size: 24, cachelines: 1, members: 3 */
/* padding: 4 */
/* last cacheline: 24 bytes */
};
<SNIP>
One can combine with -x/--exclude to remove from the output common
patterns such as 'struct trace_event_' structs:
$ pahole --with_flexible_array --padding_ge 4 --exclude trace_event_ | grep ^struct
struct rseq {
struct mem_cgroup {
struct netprio_map {
struct qdisc_size_table {
struct sysinfo {
struct ethtool_rxnfc {
struct ioam6_schema {
struct poll_list {
struct posix_acl {
struct proc_dir_entry {
struct scsi_vpd {
struct xsk_buff_pool {
struct ieee80211_regdomain {
struct watch_filter {
struct landlock_rule {
struct ghes_vendor_record_entry {
struct packet_fanout {
struct name_cache_entry {
struct workqueue_struct {
struct svc_deferred_req {
struct cis_cache_entry {
struct sem_undo {
struct sidtab_str_cache {
struct pcpu_chunk {
struct pericom8250 {
struct dm_name_list {
struct linux_dirent64 {
struct old_linux_dirent {
struct linux_dirent {
$
Cc: "Gustavo A. R. Silva" <gustavoars@xxxxxxxxxx>
Cc: Willy Tarreau <w@xxxxxx>
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
man-pages/pahole.1 | 4 ++++
pahole.c | 12 +++++++++++-
2 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/man-pages/pahole.1 b/man-pages/pahole.1
index 0a9d8ac49fbf94d5..840f8e13807ba1be 100644
--- a/man-pages/pahole.1
+++ b/man-pages/pahole.1
@@ -223,6 +223,10 @@ Find pointers to CLASS_NAME.
.B \-H, \-\-holes=NR_HOLES
Show only structs with at least NR_HOLES holes.
+.TP
+.B \-\-padding_ge=SIZE_PADDING
+Show only structs with at least SIZE_PADDING bytes of padding at its end.
+
.TP
.B \-I, \-\-show_decl_info
Show the file and line number where the tags were defined, if available in
diff --git a/pahole.c b/pahole.c
index a33490d698ead7d5..56b0ca0c55993100 100644
--- a/pahole.c
+++ b/pahole.c
@@ -60,6 +60,7 @@ static char *decl_exclude_prefix;
static size_t decl_exclude_prefix_len;
static uint16_t nr_holes;
+static uint16_t end_padding_ge;
static uint16_t nr_bit_holes;
static uint16_t hole_size_ge;
static uint8_t show_packable;
@@ -824,12 +825,13 @@ static struct class *class__filter(struct class *class, struct cu *cu,
* that need finding holes, like --packable, --nr_holes, etc
*/
if (!tag__is_struct(tag))
- return (just_structs || show_packable || nr_holes || nr_bit_holes || hole_size_ge) ? NULL : class;
+ return (just_structs || show_packable || nr_holes || nr_bit_holes || hole_size_ge || end_padding_ge) ? NULL : class;
if (tag->top_level)
class__find_holes(class);
if (class->nr_holes < nr_holes ||
+ class->padding < end_padding_ge ||
class->nr_bit_holes < nr_bit_holes ||
(hole_size_ge != 0 && !class__has_hole_ge(class, hole_size_ge)))
return NULL;
@@ -1239,6 +1241,7 @@ ARGP_PROGRAM_VERSION_HOOK_DEF = dwarves_print_version;
#define ARGP_contains_enumerator 344
#define ARGP_reproducible_build 345
#define ARGP_running_kernel_vmlinux 346
+#define ARG_PADDING_GE 347
/* --btf_features=feature1[,feature2,..] allows us to specify
* a list of requested BTF features or "default" to enable all default
@@ -1494,6 +1497,12 @@ static const struct argp_option pahole__options[] = {
.arg = "NR_HOLES",
.doc = "show only structs with at least NR_HOLES holes",
},
+ {
+ .name = "padding_ge",
+ .key = ARG_PADDING_GE,
+ .arg = "SIZE_PADDING",
+ .doc = "show only structs with at least SIZE_PADDING bytes padding at its end",
+ },
{
.name = "hole_size_ge",
.key = 'z',
@@ -1885,6 +1894,7 @@ static error_t pahole__options_parser(int key, char *arg,
class_name = arg; break;
case 'F': conf_load.format_path = arg; break;
case 'H': nr_holes = atoi(arg); break;
+ case ARG_PADDING_GE: end_padding_ge = atoi(arg); break;
case 'I': conf.show_decl_info = 1;
conf_load.extra_dbg_info = 1; break;
case 'i': find_containers = 1;
--
2.46.0
