From deb54bfe6e725368dc60d705dce6f1ec8a99ec71 Mon Sep 17 00:00:00 2001 From: Dev Jain Date: Tue, 21 May 2024 13:13:57 +0530 Subject: [PATCH] selftests/mm: compaction_test: fix incorrect write of zero to nr_hugepages [ Upstream commit 9ad665ef55eaad1ead1406a58a34f615a7c18b5e ] Currently, the test tries to set nr_hugepages to zero, but that is not actually done because the file offset is not reset after read(). Fix that using lseek(). Link: https://lkml.kernel.org/r/20240521074358.675031-3-dev.jain@arm.com Fixes: bd67d5c15cc1 ("Test compaction of mlocked memory") Signed-off-by: Dev Jain Cc: Cc: Anshuman Khandual Cc: Shuah Khan Cc: Sri Jayaramappa Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin --- tools/testing/selftests/vm/compaction_test.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/testing/selftests/vm/compaction_test.c b/tools/testing/selftests/vm/compaction_test.c index 9b420140b..55dec92e1 100755 --- a/tools/testing/selftests/vm/compaction_test.c +++ b/tools/testing/selftests/vm/compaction_test.c @@ -103,6 +103,8 @@ int check_compaction(unsigned long mem_free, unsigned int hugepage_size) goto close_fd; } + lseek(fd, 0, SEEK_SET); + /* Start with the initial condition of 0 huge pages*/ if (write(fd, "0", sizeof(char)) != sizeof(char)) { perror("Failed to write 0 to /proc/sys/vm/nr_hugepages\n");