bpf.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Ilya Leoshkevich <iii@linux.ibm.com>
To: bpf@vger.kernel.org, netdev@vger.kernel.org
Cc: gor@linux.ibm.com, heiko.carstens@de.ibm.com,
	Ilya Leoshkevich <iii@linux.ibm.com>
Subject: [PATCH bpf] selftests/bpf: make directory prerequisites order-only
Date: Fri, 12 Jul 2019 15:56:31 +0200	[thread overview]
Message-ID: <20190712135631.91398-1-iii@linux.ibm.com> (raw)

When directories are used as prerequisites in Makefiles, they can cause
a lot of unnecessary rebuilds, because a directory is considered changed
whenever a file in this directory is added, removed or modified.

If the only thing a target is interested in is the existence of the
directory it depends on, which is the case for selftests/bpf, this
directory should be specified as an order-only prerequisite: it would
still be created in case it does not exist, but it would not trigger a
rebuild of a target in case it's considered changed.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 tools/testing/selftests/bpf/Makefile | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 277d8605e340..0e003fb6641b 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -183,12 +183,12 @@ TEST_CUSTOM_PROGS += $(ALU32_BUILD_DIR)/test_progs_32
 $(ALU32_BUILD_DIR):
 	mkdir -p $@
 
-$(ALU32_BUILD_DIR)/urandom_read: $(OUTPUT)/urandom_read
+$(ALU32_BUILD_DIR)/urandom_read: $(OUTPUT)/urandom_read | $(ALU32_BUILD_DIR)
 	cp $< $@
 
 $(ALU32_BUILD_DIR)/test_progs_32: test_progs.c $(OUTPUT)/libbpf.a\
-						$(ALU32_BUILD_DIR) \
-						$(ALU32_BUILD_DIR)/urandom_read
+						$(ALU32_BUILD_DIR)/urandom_read \
+						| $(ALU32_BUILD_DIR)
 	$(CC) $(TEST_PROGS_CFLAGS) $(CFLAGS) \
 		-o $(ALU32_BUILD_DIR)/test_progs_32 \
 		test_progs.c test_stub.c trace_helpers.c prog_tests/*.c \
@@ -197,8 +197,8 @@ $(ALU32_BUILD_DIR)/test_progs_32: test_progs.c $(OUTPUT)/libbpf.a\
 $(ALU32_BUILD_DIR)/test_progs_32: $(PROG_TESTS_H)
 $(ALU32_BUILD_DIR)/test_progs_32: prog_tests/*.c
 
-$(ALU32_BUILD_DIR)/%.o: progs/%.c $(ALU32_BUILD_DIR) \
-					$(ALU32_BUILD_DIR)/test_progs_32
+$(ALU32_BUILD_DIR)/%.o: progs/%.c $(ALU32_BUILD_DIR)/test_progs_32 \
+					| $(ALU32_BUILD_DIR)
 	($(CLANG) $(CLANG_FLAGS) -O2 -target bpf -emit-llvm -c $< -o - || \
 		echo "clang failed") | \
 	$(LLC) -march=bpf -mattr=+alu32 -mcpu=$(CPU) $(LLC_FLAGS) \
@@ -236,7 +236,7 @@ $(PROG_TESTS_DIR):
 	mkdir -p $@
 
 PROG_TESTS_FILES := $(wildcard prog_tests/*.c)
-$(PROG_TESTS_H): $(PROG_TESTS_DIR) $(PROG_TESTS_FILES)
+$(PROG_TESTS_H): $(PROG_TESTS_FILES) | $(PROG_TESTS_DIR)
 	$(shell ( cd prog_tests/; \
 		  echo '/* Generated header, do not edit */'; \
 		  echo '#ifdef DECLARE'; \
@@ -257,7 +257,7 @@ MAP_TESTS_H := $(MAP_TESTS_DIR)/tests.h
 test_maps.c: $(MAP_TESTS_H)
 $(OUTPUT)/test_maps: CFLAGS += $(TEST_MAPS_CFLAGS)
 MAP_TESTS_FILES := $(wildcard map_tests/*.c)
-$(MAP_TESTS_H): $(MAP_TESTS_DIR) $(MAP_TESTS_FILES)
+$(MAP_TESTS_H): $(MAP_TESTS_FILES) | $(MAP_TESTS_DIR)
 	$(shell ( cd map_tests/; \
 		  echo '/* Generated header, do not edit */'; \
 		  echo '#ifdef DECLARE'; \
@@ -279,7 +279,7 @@ $(VERIFIER_TESTS_DIR):
 	mkdir -p $@
 
 VERIFIER_TEST_FILES := $(wildcard verifier/*.c)
-$(OUTPUT)/verifier/tests.h: $(VERIFIER_TESTS_DIR) $(VERIFIER_TEST_FILES)
+$(OUTPUT)/verifier/tests.h: $(VERIFIER_TEST_FILES) | $(VERIFIER_TESTS_DIR)
 	$(shell ( cd verifier/; \
 		  echo '/* Generated header, do not edit */'; \
 		  echo '#ifdef FILL_ARRAY'; \
-- 
2.21.0


             reply	other threads:[~2019-07-12 13:56 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-12 13:56 Ilya Leoshkevich [this message]
2019-07-12 19:57 ` [PATCH bpf] selftests/bpf: make directory prerequisites order-only Andrii Nakryiko
2019-07-15 22:19 ` Daniel Borkmann
2019-07-16 17:49   ` Alexei Starovoitov
2019-07-16 19:39     ` Andrii Nakryiko
2019-07-17  9:10     ` Ilya Leoshkevich

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=20190712135631.91398-1-iii@linux.ibm.com \
    --to=iii@linux.ibm.com \
    --cc=bpf@vger.kernel.org \
    --cc=gor@linux.ibm.com \
    --cc=heiko.carstens@de.ibm.com \
    --cc=netdev@vger.kernel.org \
    /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).