From: pengdonglin <pengdonglin@xiaomi.com>
Improve btf_find_by_name_kind() performance by adding binary search
support for sorted types. Falls back to linear search for compatibility.
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Ihor Solodrai <ihor.solodrai@linux.dev>
Cc: Xiaoqin Zhang <zhangxiaoqin@xiaomi.com>
Signed-off-by: pengdonglin <pengdonglin@xiaomi.com>
---
kernel/bpf/btf.c | 85 +++++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 76 insertions(+), 9 deletions(-)
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 0de8fc8a0e0b..0394f0c8ef74 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -259,6 +259,7 @@ struct btf {
void *nohdr_data;
struct btf_header hdr;
u32 nr_types; /* includes VOID for base BTF */
+ u32 sorted_start_id;
u32 types_size;
u32 data_size;
refcount_t refcnt;
@@ -494,6 +495,11 @@ static bool btf_type_is_modifier(const struct btf_type *t)
return false;
}
+static int btf_start_id(const struct btf *btf)
+{
+ return btf->start_id + (btf->base_btf ? 0 : 1);
+}
+
bool btf_type_is_void(const struct btf_type *t)
{
return t == &btf_void;
@@ -544,21 +550,79 @@ u32 btf_nr_types(const struct btf *btf)
return total;
}
+static s32 btf_find_by_name_bsearch(const struct btf *btf, const char *name,
+ s32 start_id, s32 end_id)
+{
+ const struct btf_type *t;
+ const char *tname;
+ s32 l, r, m, lmost = -ENOENT;
+ int ret;
+
+ l = start_id;
+ r = end_id;
+ while (l <= r) {
+ m = l + (r - l) / 2;
+ t = btf_type_by_id(btf, m);
+ tname = btf_name_by_offset(btf, t->name_off);
+ ret = strcmp(tname, name);
+ if (ret < 0) {
+ l = m + 1;
+ } else {
+ if (ret == 0)
+ lmost = m;
+ r = m - 1;
+ }
+ }
+
+ return lmost;
+}
+
s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind)
{
+ const struct btf *base_btf = btf_base_btf(btf);
const struct btf_type *t;
const char *tname;
- u32 i, total;
+ s32 idx;
- total = btf_nr_types(btf);
- for (i = 1; i < total; i++) {
- t = btf_type_by_id(btf, i);
- if (BTF_INFO_KIND(t->info) != kind)
- continue;
+ if (base_btf) {
+ idx = btf_find_by_name_kind(base_btf, name, kind);
+ if (idx > 0)
+ return idx;
+ }
- tname = btf_name_by_offset(btf, t->name_off);
- if (!strcmp(tname, name))
- return i;
+ if (btf->sorted_start_id > 0 && name[0]) {
+ /* skip anonymous types */
+ s32 start_id = btf->sorted_start_id;
+ s32 end_id = btf_nr_types(btf) - 1;
+
+ idx = btf_find_by_name_bsearch(btf, name, start_id, end_id);
+ if (idx < 0)
+ return -ENOENT;
+
+ t = btf_type_by_id(btf, idx);
+ if (BTF_INFO_KIND(t->info) == kind)
+ return idx;
+
+ for (idx++; idx <= end_id; idx++) {
+ t = btf_type_by_id(btf, idx);
+ tname = btf_name_by_offset(btf, t->name_off);
+ if (strcmp(tname, name) != 0)
+ return -ENOENT;
+ if (BTF_INFO_KIND(t->info) == kind)
+ return idx;
+ }
+ } else {
+ u32 i, total;
+
+ total = btf_nr_types(btf);
+ for (i = btf_start_id(btf); i < total; i++) {
+ t = btf_type_by_id(btf, i);
+ if (BTF_INFO_KIND(t->info) != kind)
+ continue;
+ tname = btf_name_by_offset(btf, t->name_off);
+ if (strcmp(tname, name) == 0)
+ return i;
+ }
}
return -ENOENT;
@@ -5791,6 +5855,7 @@ static struct btf *btf_parse(const union bpf_attr *attr, bpfptr_t uattr, u32 uat
goto errout;
}
env->btf = btf;
+ btf->sorted_start_id = 0;
data = kvmalloc(attr->btf_size, GFP_KERNEL | __GFP_NOWARN);
if (!data) {
@@ -6210,6 +6275,7 @@ static struct btf *btf_parse_base(struct btf_verifier_env *env, const char *name
btf->data = data;
btf->data_size = data_size;
btf->kernel_btf = true;
+ btf->sorted_start_id = 0;
snprintf(btf->name, sizeof(btf->name), "%s", name);
err = btf_parse_hdr(env);
@@ -6327,6 +6393,7 @@ static struct btf *btf_parse_module(const char *module_name, const void *data,
btf->start_id = base_btf->nr_types;
btf->start_str_off = base_btf->hdr.str_len;
btf->kernel_btf = true;
+ btf->sorted_start_id = 0;
snprintf(btf->name, sizeof(btf->name), "%s", module_name);
btf->data = kvmemdup(data, data_size, GFP_KERNEL | __GFP_NOWARN);
--
2.34.1On Thu, 2025-12-18 at 19:30 +0800, Donglin Peng wrote:
> From: pengdonglin <pengdonglin@xiaomi.com>
>
> Improve btf_find_by_name_kind() performance by adding binary search
> support for sorted types. Falls back to linear search for compatibility.
>
> Cc: Eduard Zingerman <eddyz87@gmail.com>
> Cc: Alexei Starovoitov <ast@kernel.org>
> Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
> Cc: Alan Maguire <alan.maguire@oracle.com>
> Cc: Ihor Solodrai <ihor.solodrai@linux.dev>
> Cc: Xiaoqin Zhang <zhangxiaoqin@xiaomi.com>
> Signed-off-by: pengdonglin <pengdonglin@xiaomi.com>
> ---
(One nit below).
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
> kernel/bpf/btf.c | 85 +++++++++++++++++++++++++++++++++++++++++++-----
> 1 file changed, 76 insertions(+), 9 deletions(-)
>
> diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
> index 0de8fc8a0e0b..0394f0c8ef74 100644
> --- a/kernel/bpf/btf.c
> +++ b/kernel/bpf/btf.c
> @@ -259,6 +259,7 @@ struct btf {
> void *nohdr_data;
> struct btf_header hdr;
> u32 nr_types; /* includes VOID for base BTF */
> + u32 sorted_start_id;
> u32 types_size;
> u32 data_size;
> refcount_t refcnt;
> @@ -494,6 +495,11 @@ static bool btf_type_is_modifier(const struct btf_type *t)
> return false;
> }
>
> +static int btf_start_id(const struct btf *btf)
> +{
> + return btf->start_id + (btf->base_btf ? 0 : 1);
> +}
> +
> bool btf_type_is_void(const struct btf_type *t)
> {
> return t == &btf_void;
> @@ -544,21 +550,79 @@ u32 btf_nr_types(const struct btf *btf)
> return total;
> }
>
> +static s32 btf_find_by_name_bsearch(const struct btf *btf, const char *name,
> + s32 start_id, s32 end_id)
> +{
> + const struct btf_type *t;
> + const char *tname;
> + s32 l, r, m, lmost = -ENOENT;
> + int ret;
> +
> + l = start_id;
> + r = end_id;
> + while (l <= r) {
> + m = l + (r - l) / 2;
> + t = btf_type_by_id(btf, m);
> + tname = btf_name_by_offset(btf, t->name_off);
> + ret = strcmp(tname, name);
> + if (ret < 0) {
> + l = m + 1;
> + } else {
> + if (ret == 0)
> + lmost = m;
> + r = m - 1;
> + }
> + }
> +
> + return lmost;
> +}
> +
> s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind)
> {
> + const struct btf *base_btf = btf_base_btf(btf);
> const struct btf_type *t;
> const char *tname;
> - u32 i, total;
> + s32 idx;
>
> - total = btf_nr_types(btf);
> - for (i = 1; i < total; i++) {
> - t = btf_type_by_id(btf, i);
> - if (BTF_INFO_KIND(t->info) != kind)
> - continue;
> + if (base_btf) {
> + idx = btf_find_by_name_kind(base_btf, name, kind);
> + if (idx > 0)
> + return idx;
> + }
>
> - tname = btf_name_by_offset(btf, t->name_off);
> - if (!strcmp(tname, name))
> - return i;
> + if (btf->sorted_start_id > 0 && name[0]) {
^^^^^^^^^^^^^^^^^^^^^^^^
Nit: Maybe pull the is_sorted helper into this patch-set?
> + /* skip anonymous types */
> + s32 start_id = btf->sorted_start_id;
> + s32 end_id = btf_nr_types(btf) - 1;
> +
> + idx = btf_find_by_name_bsearch(btf, name, start_id, end_id);
> + if (idx < 0)
> + return -ENOENT;
> +
> + t = btf_type_by_id(btf, idx);
> + if (BTF_INFO_KIND(t->info) == kind)
> + return idx;
> +
> + for (idx++; idx <= end_id; idx++) {
> + t = btf_type_by_id(btf, idx);
> + tname = btf_name_by_offset(btf, t->name_off);
> + if (strcmp(tname, name) != 0)
> + return -ENOENT;
> + if (BTF_INFO_KIND(t->info) == kind)
> + return idx;
> + }
> + } else {
> + u32 i, total;
> +
> + total = btf_nr_types(btf);
> + for (i = btf_start_id(btf); i < total; i++) {
> + t = btf_type_by_id(btf, i);
> + if (BTF_INFO_KIND(t->info) != kind)
> + continue;
> + tname = btf_name_by_offset(btf, t->name_off);
> + if (strcmp(tname, name) == 0)
> + return i;
> + }
> }
>
> return -ENOENT;
> @@ -5791,6 +5855,7 @@ static struct btf *btf_parse(const union bpf_attr *attr, bpfptr_t uattr, u32 uat
> goto errout;
> }
> env->btf = btf;
> + btf->sorted_start_id = 0;
>
> data = kvmalloc(attr->btf_size, GFP_KERNEL | __GFP_NOWARN);
> if (!data) {
> @@ -6210,6 +6275,7 @@ static struct btf *btf_parse_base(struct btf_verifier_env *env, const char *name
> btf->data = data;
> btf->data_size = data_size;
> btf->kernel_btf = true;
> + btf->sorted_start_id = 0;
> snprintf(btf->name, sizeof(btf->name), "%s", name);
>
> err = btf_parse_hdr(env);
> @@ -6327,6 +6393,7 @@ static struct btf *btf_parse_module(const char *module_name, const void *data,
> btf->start_id = base_btf->nr_types;
> btf->start_str_off = base_btf->hdr.str_len;
> btf->kernel_btf = true;
> + btf->sorted_start_id = 0;
> snprintf(btf->name, sizeof(btf->name), "%s", module_name);
>
> btf->data = kvmemdup(data, data_size, GFP_KERNEL | __GFP_NOWARN);
On Fri, Dec 19, 2025 at 5:38 AM Eduard Zingerman <eddyz87@gmail.com> wrote:
>
> On Thu, 2025-12-18 at 19:30 +0800, Donglin Peng wrote:
> > From: pengdonglin <pengdonglin@xiaomi.com>
> >
> > Improve btf_find_by_name_kind() performance by adding binary search
> > support for sorted types. Falls back to linear search for compatibility.
> >
> > Cc: Eduard Zingerman <eddyz87@gmail.com>
> > Cc: Alexei Starovoitov <ast@kernel.org>
> > Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
> > Cc: Alan Maguire <alan.maguire@oracle.com>
> > Cc: Ihor Solodrai <ihor.solodrai@linux.dev>
> > Cc: Xiaoqin Zhang <zhangxiaoqin@xiaomi.com>
> > Signed-off-by: pengdonglin <pengdonglin@xiaomi.com>
> > ---
>
> (One nit below).
>
> Acked-by: Eduard Zingerman <eddyz87@gmail.com>
>
> > kernel/bpf/btf.c | 85 +++++++++++++++++++++++++++++++++++++++++++-----
> > 1 file changed, 76 insertions(+), 9 deletions(-)
> >
> > diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
> > index 0de8fc8a0e0b..0394f0c8ef74 100644
> > --- a/kernel/bpf/btf.c
> > +++ b/kernel/bpf/btf.c
> > @@ -259,6 +259,7 @@ struct btf {
> > void *nohdr_data;
> > struct btf_header hdr;
> > u32 nr_types; /* includes VOID for base BTF */
> > + u32 sorted_start_id;
> > u32 types_size;
> > u32 data_size;
> > refcount_t refcnt;
> > @@ -494,6 +495,11 @@ static bool btf_type_is_modifier(const struct btf_type *t)
> > return false;
> > }
> >
> > +static int btf_start_id(const struct btf *btf)
> > +{
> > + return btf->start_id + (btf->base_btf ? 0 : 1);
> > +}
> > +
> > bool btf_type_is_void(const struct btf_type *t)
> > {
> > return t == &btf_void;
> > @@ -544,21 +550,79 @@ u32 btf_nr_types(const struct btf *btf)
> > return total;
> > }
> >
> > +static s32 btf_find_by_name_bsearch(const struct btf *btf, const char *name,
> > + s32 start_id, s32 end_id)
> > +{
> > + const struct btf_type *t;
> > + const char *tname;
> > + s32 l, r, m, lmost = -ENOENT;
> > + int ret;
> > +
> > + l = start_id;
> > + r = end_id;
> > + while (l <= r) {
> > + m = l + (r - l) / 2;
> > + t = btf_type_by_id(btf, m);
> > + tname = btf_name_by_offset(btf, t->name_off);
> > + ret = strcmp(tname, name);
> > + if (ret < 0) {
> > + l = m + 1;
> > + } else {
> > + if (ret == 0)
> > + lmost = m;
> > + r = m - 1;
> > + }
> > + }
> > +
> > + return lmost;
> > +}
> > +
> > s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind)
> > {
> > + const struct btf *base_btf = btf_base_btf(btf);
> > const struct btf_type *t;
> > const char *tname;
> > - u32 i, total;
> > + s32 idx;
> >
> > - total = btf_nr_types(btf);
> > - for (i = 1; i < total; i++) {
> > - t = btf_type_by_id(btf, i);
> > - if (BTF_INFO_KIND(t->info) != kind)
> > - continue;
> > + if (base_btf) {
> > + idx = btf_find_by_name_kind(base_btf, name, kind);
> > + if (idx > 0)
> > + return idx;
> > + }
> >
> > - tname = btf_name_by_offset(btf, t->name_off);
> > - if (!strcmp(tname, name))
> > - return i;
> > + if (btf->sorted_start_id > 0 && name[0]) {
> ^^^^^^^^^^^^^^^^^^^^^^^^
> Nit: Maybe pull the is_sorted helper into this patch-set?
Thanks, will do it.
>
> > + /* skip anonymous types */
> > + s32 start_id = btf->sorted_start_id;
> > + s32 end_id = btf_nr_types(btf) - 1;
> > +
> > + idx = btf_find_by_name_bsearch(btf, name, start_id, end_id);
> > + if (idx < 0)
> > + return -ENOENT;
> > +
> > + t = btf_type_by_id(btf, idx);
> > + if (BTF_INFO_KIND(t->info) == kind)
> > + return idx;
> > +
> > + for (idx++; idx <= end_id; idx++) {
> > + t = btf_type_by_id(btf, idx);
> > + tname = btf_name_by_offset(btf, t->name_off);
> > + if (strcmp(tname, name) != 0)
> > + return -ENOENT;
> > + if (BTF_INFO_KIND(t->info) == kind)
> > + return idx;
> > + }
> > + } else {
> > + u32 i, total;
> > +
> > + total = btf_nr_types(btf);
> > + for (i = btf_start_id(btf); i < total; i++) {
> > + t = btf_type_by_id(btf, i);
> > + if (BTF_INFO_KIND(t->info) != kind)
> > + continue;
> > + tname = btf_name_by_offset(btf, t->name_off);
> > + if (strcmp(tname, name) == 0)
> > + return i;
> > + }
> > }
> >
> > return -ENOENT;
> > @@ -5791,6 +5855,7 @@ static struct btf *btf_parse(const union bpf_attr *attr, bpfptr_t uattr, u32 uat
> > goto errout;
> > }
> > env->btf = btf;
> > + btf->sorted_start_id = 0;
> >
> > data = kvmalloc(attr->btf_size, GFP_KERNEL | __GFP_NOWARN);
> > if (!data) {
> > @@ -6210,6 +6275,7 @@ static struct btf *btf_parse_base(struct btf_verifier_env *env, const char *name
> > btf->data = data;
> > btf->data_size = data_size;
> > btf->kernel_btf = true;
> > + btf->sorted_start_id = 0;
> > snprintf(btf->name, sizeof(btf->name), "%s", name);
> >
> > err = btf_parse_hdr(env);
> > @@ -6327,6 +6393,7 @@ static struct btf *btf_parse_module(const char *module_name, const void *data,
> > btf->start_id = base_btf->nr_types;
> > btf->start_str_off = base_btf->hdr.str_len;
> > btf->kernel_btf = true;
> > + btf->sorted_start_id = 0;
> > snprintf(btf->name, sizeof(btf->name), "%s", module_name);
> >
> > btf->data = kvmemdup(data, data_size, GFP_KERNEL | __GFP_NOWARN);
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