Pahole v1.32 and later supports BTF sorting. Add a new configuration
option to control whether to enable this feature for vmlinux and
kernel modules.
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: Song Liu <song@kernel.org>
Signed-off-by: pengdonglin <pengdonglin@xiaomi.com>
Signed-off-by: Donglin Peng <dolinux.peng@gmail.com>
---
kernel/bpf/Kconfig | 8 ++++++++
scripts/Makefile.btf | 5 +++++
2 files changed, 13 insertions(+)
diff --git a/kernel/bpf/Kconfig b/kernel/bpf/Kconfig
index eb3de35734f0..08251a250f06 100644
--- a/kernel/bpf/Kconfig
+++ b/kernel/bpf/Kconfig
@@ -101,4 +101,12 @@ config BPF_LSM
If you are unsure how to answer this question, answer N.
+config BPF_SORT_BTF_BY_KIND_NAME
+ bool "Sort BTF types by kind and name"
+ depends on BPF_SYSCALL
+ help
+ This option sorts BTF types in vmlinux and kernel modules by their
+ kind and name, enabling binary search for btf_find_by_name_kind()
+ and significantly improving its lookup performance.
+
endmenu # "BPF subsystem"
diff --git a/scripts/Makefile.btf b/scripts/Makefile.btf
index db76335dd917..3f1a0b3c3f3f 100644
--- a/scripts/Makefile.btf
+++ b/scripts/Makefile.btf
@@ -29,6 +29,11 @@ ifneq ($(KBUILD_EXTMOD),)
module-pahole-flags-$(call test-ge, $(pahole-ver), 128) += --btf_features=distilled_base
endif
+ifeq ($(call test-ge, $(pahole-ver), 132),y)
+pahole-flags-$(CONFIG_BPF_SORT_BTF_BY_KIND_NAME) += --btf_features=sort
+module-pahole-flags-$(CONFIG_BPF_SORT_BTF_BY_KIND_NAME) += --btf_features=sort
+endif
+
endif
pahole-flags-$(CONFIG_PAHOLE_HAS_LANG_EXCLUDE) += --lang_exclude=rust
--
2.34.1On 20/10/2025 10:39, Donglin Peng wrote: > Pahole v1.32 and later supports BTF sorting. Add a new configuration > option to control whether to enable this feature for vmlinux and > kernel modules. > > 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: Song Liu <song@kernel.org> > Signed-off-by: pengdonglin <pengdonglin@xiaomi.com> > Signed-off-by: Donglin Peng <dolinux.peng@gmail.com> > --- > kernel/bpf/Kconfig | 8 ++++++++ > scripts/Makefile.btf | 5 +++++ > 2 files changed, 13 insertions(+) > > diff --git a/kernel/bpf/Kconfig b/kernel/bpf/Kconfig > index eb3de35734f0..08251a250f06 100644 > --- a/kernel/bpf/Kconfig > +++ b/kernel/bpf/Kconfig > @@ -101,4 +101,12 @@ config BPF_LSM > > If you are unsure how to answer this question, answer N. > > +config BPF_SORT_BTF_BY_KIND_NAME > + bool "Sort BTF types by kind and name" > + depends on BPF_SYSCALL > + help > + This option sorts BTF types in vmlinux and kernel modules by their > + kind and name, enabling binary search for btf_find_by_name_kind() > + and significantly improving its lookup performance. > + > endmenu # "BPF subsystem" > diff --git a/scripts/Makefile.btf b/scripts/Makefile.btf > index db76335dd917..3f1a0b3c3f3f 100644 > --- a/scripts/Makefile.btf > +++ b/scripts/Makefile.btf > @@ -29,6 +29,11 @@ ifneq ($(KBUILD_EXTMOD),) > module-pahole-flags-$(call test-ge, $(pahole-ver), 128) += --btf_features=distilled_base > endif > > +ifeq ($(call test-ge, $(pahole-ver), 132),y) > +pahole-flags-$(CONFIG_BPF_SORT_BTF_BY_KIND_NAME) += --btf_features=sort > +module-pahole-flags-$(CONFIG_BPF_SORT_BTF_BY_KIND_NAME) += --btf_features=sort > +endif > + perhaps it's useful informationally, but you don't need to wrap the addition of the sort flag in a pahole version check; unsupported btf_features are just ignored. Also we're at v1.30 in pahole now (we'll be releasing 1.31 shortly hopefully), so any version check should be v1.30/v1.31. I'd say just leave out the version check though. Alan
On Wed, Oct 22, 2025 at 1:28 AM Alan Maguire <alan.maguire@oracle.com> wrote: > > On 20/10/2025 10:39, Donglin Peng wrote: > > Pahole v1.32 and later supports BTF sorting. Add a new configuration > > option to control whether to enable this feature for vmlinux and > > kernel modules. > > > > Cc: Eduard Zingerman <eddyz87@gmail.com> > > Cc: Alexei Starovoitov <ast@kernel.org> > > Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com> > > Cc: Alan Maguire <alan.maguire@oracle.com> > > Cc: Song Liu <song@kernel.org> > > Signed-off-by: pengdonglin <pengdonglin@xiaomi.com> > > Signed-off-by: Donglin Peng <dolinux.peng@gmail.com> > > --- > > kernel/bpf/Kconfig | 8 ++++++++ > > scripts/Makefile.btf | 5 +++++ > > 2 files changed, 13 insertions(+) > > > > diff --git a/kernel/bpf/Kconfig b/kernel/bpf/Kconfig > > index eb3de35734f0..08251a250f06 100644 > > --- a/kernel/bpf/Kconfig > > +++ b/kernel/bpf/Kconfig > > @@ -101,4 +101,12 @@ config BPF_LSM > > > > If you are unsure how to answer this question, answer N. > > > > +config BPF_SORT_BTF_BY_KIND_NAME > > + bool "Sort BTF types by kind and name" > > + depends on BPF_SYSCALL > > + help > > + This option sorts BTF types in vmlinux and kernel modules by their > > + kind and name, enabling binary search for btf_find_by_name_kind() > > + and significantly improving its lookup performance. > > + > > endmenu # "BPF subsystem" > > diff --git a/scripts/Makefile.btf b/scripts/Makefile.btf > > index db76335dd917..3f1a0b3c3f3f 100644 > > --- a/scripts/Makefile.btf > > +++ b/scripts/Makefile.btf > > @@ -29,6 +29,11 @@ ifneq ($(KBUILD_EXTMOD),) > > module-pahole-flags-$(call test-ge, $(pahole-ver), 128) += --btf_features=distilled_base > > endif > > > > +ifeq ($(call test-ge, $(pahole-ver), 132),y) > > +pahole-flags-$(CONFIG_BPF_SORT_BTF_BY_KIND_NAME) += --btf_features=sort > > +module-pahole-flags-$(CONFIG_BPF_SORT_BTF_BY_KIND_NAME) += --btf_features=sort > > +endif > > + > > perhaps it's useful informationally, but you don't need to wrap the > addition of the sort flag in a pahole version check; unsupported > btf_features are just ignored. Also we're at v1.30 in pahole now (we'll > be releasing 1.31 shortly hopefully), so any version check should be > v1.30/v1.31. I'd say just leave out the version check though. Understood, thanks. Will do. > > Alan
On Mon, 2025-10-20 at 17:39 +0800, Donglin Peng wrote: [...] > diff --git a/kernel/bpf/Kconfig b/kernel/bpf/Kconfig > index eb3de35734f0..08251a250f06 100644 > --- a/kernel/bpf/Kconfig > +++ b/kernel/bpf/Kconfig > @@ -101,4 +101,12 @@ config BPF_LSM > > If you are unsure how to answer this question, answer N. > > +config BPF_SORT_BTF_BY_KIND_NAME > + bool "Sort BTF types by kind and name" > + depends on BPF_SYSCALL > + help > + This option sorts BTF types in vmlinux and kernel modules by their > + kind and name, enabling binary search for btf_find_by_name_kind() > + and significantly improving its lookup performance. > + Why having this as an option? There are no downsides to always enabling, right? The cost of sorting btf at build time should be negligible. [...]
On Tue, Oct 21, 2025 at 8:50 AM Eduard Zingerman <eddyz87@gmail.com> wrote: > > On Mon, 2025-10-20 at 17:39 +0800, Donglin Peng wrote: > > [...] > > > diff --git a/kernel/bpf/Kconfig b/kernel/bpf/Kconfig > > index eb3de35734f0..08251a250f06 100644 > > --- a/kernel/bpf/Kconfig > > +++ b/kernel/bpf/Kconfig > > @@ -101,4 +101,12 @@ config BPF_LSM > > > > If you are unsure how to answer this question, answer N. > > > > +config BPF_SORT_BTF_BY_KIND_NAME > > + bool "Sort BTF types by kind and name" > > + depends on BPF_SYSCALL > > + help > > + This option sorts BTF types in vmlinux and kernel modules by their > > + kind and name, enabling binary search for btf_find_by_name_kind() > > + and significantly improving its lookup performance. > > + > > Why having this as an option? > There are no downsides to always enabling, right? > The cost of sorting btf at build time should be negligible. Thanks, I'll remove this config option in the next version as suggested. > > [...]
© 2016 - 2026 Red Hat, Inc.