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From:   John Hubbard <jhubbard@nvidia.com>
To:     Andrew Morton <akpm@linux-foundation.org>
CC:     Shuah Khan <shuah@kernel.org>, LKML <linux-kernel@vger.kernel.org>,
        <linux-mm@kvack.org>, <linux-kselftest@vger.kernel.org>,
        John Hubbard <jhubbard@nvidia.com>
Subject: [PATCH 1/2] selftests/vm: fix false build success on the second and later attempts
Date:   Mon, 14 Sep 2020 18:29:00 -0700
Message-ID: <20200915012901.1655280-2-jhubbard@nvidia.com>
In-Reply-To: <20200915012901.1655280-1-jhubbard@nvidia.com>
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If one or more of these selftest fail to build, then after the first
failure, subsequent invocations of "make" will make it appear that there
are no build failures, after all.

That's because the failed build products remain, with up-to-date
timestamps, thus tricking Make (and you!) into believing that there's
nothing else to build.

Fix this by telling Make to delete targets that didn't completely
succeed.

Signed-off-by: John Hubbard <jhubbard@nvidia.com>
---
 tools/testing/selftests/vm/Makefile | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/=
vm/Makefile
index a9026706d597..9f2625bebf07 100644
--- a/tools/testing/selftests/vm/Makefile
+++ b/tools/testing/selftests/vm/Makefile
@@ -3,6 +3,11 @@
 uname_M :=3D $(shell uname -m 2>/dev/null || echo not)
 MACHINE ?=3D $(shell echo $(uname_M) | sed -e 's/aarch64.*/arm64/')
=20
+# Without this, failed build products remain, with up-to-date timestamps,
+# thus tricking Make (and you!) into believing that All Is Well, in subseq=
uent
+# make invocations:
+.DELETE_ON_ERROR:
+
 CFLAGS =3D -Wall -I ../../../../usr/include $(EXTRA_CFLAGS)
 LDLIBS =3D -lrt
 TEST_GEN_FILES =3D compaction_test
--=20
2.28.0