From: Andrii Nakryiko <andrii.nakryiko@gmail.com>
To: "Toke Høiland-Jørgensen" <toke@redhat.com>
Cc: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
Yonghong Song <yhs@fb.com>, Andrii Nakryiko <andriin@fb.com>,
Doug Ledford <dledford@redhat.com>,
Jason Gunthorpe <jgg@ziepe.ca>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Jesper Dangaard Brouer <brouer@redhat.com>,
John Fastabend <john.fastabend@gmail.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
Shuah Khan <shuah@kernel.org>,
Networking <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>,
open list <linux-kernel@vger.kernel.org>,
linux-rdma@vger.kernel.org,
"open list:KERNEL SELFTEST FRAMEWORK"
<linux-kselftest@vger.kernel.org>,
clang-built-linux@googlegroups.com
Subject: Re: [PATCH bpf-next v3 02/11] tools/bpf/runqslower: Fix override option for VMLINUX_BTF
Date: Thu, 16 Jan 2020 10:54:44 -0800 [thread overview]
Message-ID: <CAEf4Bzbz47nFh4tPBn2PTi3+YiYpMDxymgf36P=ZjbuBPoCrZg@mail.gmail.com> (raw)
In-Reply-To: <157918093389.1357254.10041649215380772130.stgit@toke.dk>
On Thu, Jan 16, 2020 at 5:23 AM Toke Høiland-Jørgensen <toke@redhat.com> wrote:
>
> From: Toke Høiland-Jørgensen <toke@redhat.com>
>
> The runqslower tool refuses to build without a file to read vmlinux BTF
> from. The build fails with an error message to override the location by
> setting the VMLINUX_BTF variable if autodetection fails. However, the
> Makefile doesn't actually work with that override - the error message is
> still emitted.
>
> Fix this by including the value of VMLINUX_BTF in the expansion, and only
> emitting the error message if the *result* is empty. Also permit running
> 'make clean' even though no VMLINUX_BTF is set.
>
> Fixes: 9c01546d26d2 ("tools/bpf: Add runqslower tool to tools/bpf")
> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
> ---
> tools/bpf/runqslower/Makefile | 18 ++++++++++--------
> 1 file changed, 10 insertions(+), 8 deletions(-)
>
> diff --git a/tools/bpf/runqslower/Makefile b/tools/bpf/runqslower/Makefile
> index cff2fbcd29a8..89fb7cd30f1a 100644
> --- a/tools/bpf/runqslower/Makefile
> +++ b/tools/bpf/runqslower/Makefile
> @@ -10,12 +10,14 @@ CFLAGS := -g -Wall
>
> # Try to detect best kernel BTF source
> KERNEL_REL := $(shell uname -r)
> -ifneq ("$(wildcard /sys/kernel/btf/vmlinux)","")
> -VMLINUX_BTF := /sys/kernel/btf/vmlinux
> -else ifneq ("$(wildcard /boot/vmlinux-$(KERNEL_REL))","")
> -VMLINUX_BTF := /boot/vmlinux-$(KERNEL_REL)
> -else
> -$(error "Can't detect kernel BTF, use VMLINUX_BTF to specify it explicitly")
> +VMLINUX_BTF_PATHS := $(VMLINUX_BTF) /sys/kernel/btf/vmlinux /boot/vmlinux-$(KERNEL_REL)
> +VMLINUX_BTF_PATH := $(firstword $(wildcard $(VMLINUX_BTF_PATHS)))
If user specifies VMLINUX_BTF pointing to non-existing file, but the
system has /sys/kernel/btf/vmlinux, the latter will still be used,
which is a very surprising behavior.
Also MAKECMDGOALS feels like a fragile hack to me. How about we move
this VMLINUX_BTF guessing (without $(error)) into vmlinux.h rule
itself and use shell if conditional after it to check for file
existance and print nice error. That way we'll be checking VMLINUX_BTF
only when it's really needed.
> +
> +ifeq ("$(VMLINUX_BTF_PATH)","")
> +ifneq ($(MAKECMDGOALS),clean)
> +$(error Could not find kernel BTF file (tried: $(VMLINUX_BTF_PATHS)). \
> + Try setting $$VMLINUX_BTF)
> +endif
> endif
>
> abs_out := $(abspath $(OUTPUT))
> @@ -67,9 +69,9 @@ $(OUTPUT):
> $(call msg,MKDIR,$@)
> $(Q)mkdir -p $(OUTPUT)
>
> -$(OUTPUT)/vmlinux.h: $(VMLINUX_BTF) | $(OUTPUT) $(BPFTOOL)
> +$(OUTPUT)/vmlinux.h: $(VMLINUX_BTF_PATH) | $(OUTPUT) $(BPFTOOL)
> $(call msg,GEN,$@)
> - $(Q)$(BPFTOOL) btf dump file $(VMLINUX_BTF) format c > $@
> + $(Q)$(BPFTOOL) btf dump file $(VMLINUX_BTF_PATH) format c > $@
>
> $(OUTPUT)/libbpf.a: | $(OUTPUT)
> $(Q)$(MAKE) $(submake_extras) -C $(LIBBPF_SRC) \
>
next prev parent reply other threads:[~2020-01-16 18:55 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-16 13:22 [PATCH bpf-next v3 00/11] tools: Use consistent libbpf include paths everywhere Toke Høiland-Jørgensen
2020-01-16 13:22 ` [PATCH bpf-next v3 01/11] samples/bpf: Don't try to remove user's homedir on clean Toke Høiland-Jørgensen
2020-01-16 13:22 ` [PATCH bpf-next v3 02/11] tools/bpf/runqslower: Fix override option for VMLINUX_BTF Toke Høiland-Jørgensen
2020-01-16 18:54 ` Andrii Nakryiko [this message]
2020-01-17 9:44 ` Toke Høiland-Jørgensen
2020-01-16 13:22 ` [PATCH bpf-next v3 03/11] selftests: Pass VMLINUX_BTF to runqslower Makefile Toke Høiland-Jørgensen
2020-01-16 18:56 ` Andrii Nakryiko
2020-01-16 13:22 ` [PATCH bpf-next v3 04/11] tools/runqslower: Use consistent include paths for libbpf Toke Høiland-Jørgensen
2020-01-16 21:56 ` Andrii Nakryiko
2020-01-17 9:46 ` Toke Høiland-Jørgensen
2020-01-16 13:22 ` [PATCH bpf-next v3 05/11] selftests: " Toke Høiland-Jørgensen
2020-01-16 21:57 ` Andrii Nakryiko
2020-01-16 13:22 ` [PATCH bpf-next v3 06/11] bpftool: " Toke Høiland-Jørgensen
2020-01-16 22:21 ` Andrii Nakryiko
2020-01-16 13:22 ` [PATCH bpf-next v3 07/11] perf: " Toke Høiland-Jørgensen
2020-01-16 22:22 ` Andrii Nakryiko
2020-01-16 13:22 ` [PATCH bpf-next v3 08/11] samples/bpf: " Toke Høiland-Jørgensen
2020-01-16 22:23 ` Andrii Nakryiko
2020-01-16 13:22 ` [PATCH bpf-next v3 09/11] selftests: Remove tools/lib/bpf from include path Toke Høiland-Jørgensen
2020-01-16 22:41 ` Andrii Nakryiko
2020-01-16 23:05 ` Andrii Nakryiko
2020-01-17 9:50 ` Toke Høiland-Jørgensen
2020-01-17 9:49 ` Toke Høiland-Jørgensen
2020-01-16 13:22 ` [PATCH bpf-next v3 10/11] tools/runqslower: " Toke Høiland-Jørgensen
2020-01-16 22:44 ` Andrii Nakryiko
2020-01-16 13:22 ` [PATCH bpf-next v3 11/11] libbpf: Fix include of bpf_helpers.h when libbpf is installed on system Toke Høiland-Jørgensen
2020-01-16 22:43 ` Andrii Nakryiko
2020-01-17 4:14 ` [PATCH bpf-next v3 00/11] tools: Use consistent libbpf include paths everywhere Alexei Starovoitov
2020-01-17 8:57 ` Jesper Dangaard Brouer
2020-01-17 9:58 ` Toke Høiland-Jørgensen
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAEf4Bzbz47nFh4tPBn2PTi3+YiYpMDxymgf36P=ZjbuBPoCrZg@mail.gmail.com' \
--to=andrii.nakryiko@gmail.com \
--cc=acme@kernel.org \
--cc=alexander.shishkin@linux.intel.com \
--cc=andriin@fb.com \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=brouer@redhat.com \
--cc=clang-built-linux@googlegroups.com \
--cc=daniel@iogearbox.net \
--cc=davem@davemloft.net \
--cc=dledford@redhat.com \
--cc=jgg@ziepe.ca \
--cc=john.fastabend@gmail.com \
--cc=jolsa@redhat.com \
--cc=kafai@fb.com \
--cc=kuba@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-kselftest@vger.kernel.org \
--cc=linux-rdma@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=mingo@redhat.com \
--cc=namhyung@kernel.org \
--cc=netdev@vger.kernel.org \
--cc=peterz@infradead.org \
--cc=shuah@kernel.org \
--cc=songliubraving@fb.com \
--cc=toke@redhat.com \
--cc=yhs@fb.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).