From nobody Tue Apr 7 06:19:21 2026 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 52D2733A031 for ; Mon, 16 Mar 2026 04:44:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773636265; cv=none; b=YYKQ2T3RcXmMbWflFE/DDLgGzFI/M1nAb3kSyFAuNfk+GwZzE6tWkRIekiLdF8nWjbuIcWdtgFsZd7enFj98W8hv034Nh8ANy02bbBE9auox+BImFWyD0Yjuouwp7DXvV66RkeALHNepPXzHXjPAmUGDWOpr/iY8W6KG8/7le3E= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773636265; c=relaxed/simple; bh=qGhnEep0RBSzZ0dq8guG7AmCL7nWwSAsr5IYP1RjcoU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=MSOJHDZ5kFnTJhchimKjfnz98J0IT7Y+NAyavNl8qVXI7KsRy0QDNht6fSa5nAvfmqGEokJVpqx3yWHX6mFCVzQCsHZFonKvEifzcBS3nC+5VpX1NxDlVGQyd2qGCZUSzSFlczZixoq4GzyFFsbSCcnUzYuTJ2GShLrEvTV6owk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=gH3hq2le; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="gH3hq2le" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1773636263; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=f0kOdSCeg55Ok0Trt0Fwz3GMewBTQG5BCQViHUjgEfw=; b=gH3hq2lefiBdpDMESBYFeDABbIoo29EywO8P3C4diDWnVhYiKqnwU1C9JZZE8sg1jgAqsq v5mSYp2AkOytd3/UB0Y+liZMgpmvwbtVbTy3uahY9L2BlU5hFYIJye53aJWd4ZCyHkpsuq hH1ujiA+FB+lDUwRghwz3p9nzWG1MDo= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-12-u9wUhbjxMVecISbYFoBuJA-1; Mon, 16 Mar 2026 00:44:19 -0400 X-MC-Unique: u9wUhbjxMVecISbYFoBuJA-1 X-Mimecast-MFC-AGG-ID: u9wUhbjxMVecISbYFoBuJA_1773636257 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id E867E19373D8; Mon, 16 Mar 2026 04:44:16 +0000 (UTC) Received: from dell-per7425-02.rhts.eng.pek2.redhat.com (dell-per7425-02.rhts.eng.pek2.redhat.com [10.73.116.18]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 4748319560B7; Mon, 16 Mar 2026 04:44:08 +0000 (UTC) From: Chunyu Hu To: akpm@linux-foundation.org, david@kernel.org, shuah@kernel.org, linux-mm@kvack.org, ljs@kernel.org Cc: linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, vbabka@suse.cz, rppt@kernel.org, surenb@google.com, mhocko@suse.com, ziy@nvidia.com, baolin.wang@linux.alibaba.com, npache@redhat.com, ryan.roberts@arm.com, dev.jain@arm.com, baohua@kernel.org, lance.yang@linux.dev, chuhu@redhat.com Subject: [PATCH v2 3/5] selftests/mm: move write_file helper to vm_util Date: Mon, 16 Mar 2026 12:43:33 +0800 Message-ID: <20260316044335.1390608-4-chuhu@redhat.com> In-Reply-To: <20260316044335.1390608-1-chuhu@redhat.com> References: <20260316044335.1390608-1-chuhu@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Content-Type: text/plain; charset="utf-8" thp_settings provides write_file() helper for safely writing to a file and exit when write failure happens. It's a very low level helper and many sub tests need such a helper, not only thp tests. split_huge_page_test also defines a write_file locally. The two have minior differences in return type and used exit api. And there would be conflicts if split_huge_page_test wanted to include thp_settings.h because of different prototype, making it less convenient. It's possisble to merge the two, although some tests don't use the kselftest infrastrucutre for testing. It would also work when using the ksft_exit_msg() to exit in my test, as the counters are all zero. Output will be like: TAP version 13 1..62 Bail out! /proc/sys/vm/drop_caches1 open failed: No such file or directory # Totals: pass:0 fail:0 xfail:0 xpass:0 skip:0 error:0 So here just leave one version of write_file, and move it into the vm_util. This make it easy to maitain and user could just include one vm_util.h when then don't need thp setting helpers. Keep the prototype of returning the written bytes num. Suggested-by: Mike Rapoport Signed-off-by: Chunyu Hu --- Changes in v2: new patch from v2 --- .../selftests/mm/split_huge_page_test.c | 15 ------------ tools/testing/selftests/mm/thp_settings.c | 24 +------------------ tools/testing/selftests/mm/thp_settings.h | 1 - tools/testing/selftests/mm/vm_util.c | 16 +++++++++++++ tools/testing/selftests/mm/vm_util.h | 2 ++ 5 files changed, 19 insertions(+), 39 deletions(-) diff --git a/tools/testing/selftests/mm/split_huge_page_test.c b/tools/test= ing/selftests/mm/split_huge_page_test.c index e0167111bdd1..93f205327b84 100644 --- a/tools/testing/selftests/mm/split_huge_page_test.c +++ b/tools/testing/selftests/mm/split_huge_page_test.c @@ -255,21 +255,6 @@ static int check_after_split_folio_orders(char *vaddr_= start, size_t len, return status; } =20 -static void write_file(const char *path, const char *buf, size_t buflen) -{ - int fd; - ssize_t numwritten; - - fd =3D open(path, O_WRONLY); - if (fd =3D=3D -1) - ksft_exit_fail_msg("%s open failed: %s\n", path, strerror(errno)); - - numwritten =3D write(fd, buf, buflen - 1); - close(fd); - if (numwritten < 1) - ksft_exit_fail_msg("Write failed\n"); -} - static void write_debugfs(const char *fmt, ...) { char input[INPUT_MAX]; diff --git a/tools/testing/selftests/mm/thp_settings.c b/tools/testing/self= tests/mm/thp_settings.c index 574bd0f8ae48..02de28ecf31a 100644 --- a/tools/testing/selftests/mm/thp_settings.c +++ b/tools/testing/selftests/mm/thp_settings.c @@ -6,6 +6,7 @@ #include #include =20 +#include "vm_util.h" #include "thp_settings.h" =20 #define THP_SYSFS "/sys/kernel/mm/transparent_hugepage/" @@ -64,29 +65,6 @@ int read_file(const char *path, char *buf, size_t buflen) return (unsigned int) numread; } =20 -int write_file(const char *path, const char *buf, size_t buflen) -{ - int fd; - ssize_t numwritten; - - fd =3D open(path, O_WRONLY); - if (fd =3D=3D -1) { - printf("open(%s)\n", path); - exit(EXIT_FAILURE); - return 0; - } - - numwritten =3D write(fd, buf, buflen - 1); - close(fd); - if (numwritten < 1) { - printf("write(%s)\n", buf); - exit(EXIT_FAILURE); - return 0; - } - - return (unsigned int) numwritten; -} - unsigned long read_num(const char *path) { char buf[21]; diff --git a/tools/testing/selftests/mm/thp_settings.h b/tools/testing/self= tests/mm/thp_settings.h index 76eeb712e5f1..7748a9009191 100644 --- a/tools/testing/selftests/mm/thp_settings.h +++ b/tools/testing/selftests/mm/thp_settings.h @@ -63,7 +63,6 @@ struct thp_settings { }; =20 int read_file(const char *path, char *buf, size_t buflen); -int write_file(const char *path, const char *buf, size_t buflen); unsigned long read_num(const char *path); void write_num(const char *path, unsigned long num); =20 diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests= /mm/vm_util.c index a6d4ff7dfdc0..b4b3b48f8dc9 100644 --- a/tools/testing/selftests/mm/vm_util.c +++ b/tools/testing/selftests/mm/vm_util.c @@ -764,3 +764,19 @@ int unpoison_memory(unsigned long pfn) =20 return ret > 0 ? 0 : -errno; } + +unsigned int write_file(const char *path, const char *buf, size_t buflen) +{ + int fd; + ssize_t numwritten; + + fd =3D open(path, O_WRONLY); + if (fd =3D=3D -1) + ksft_exit_fail_msg("%s open failed: %s\n", path, strerror(errno)); + + numwritten =3D write(fd, buf, buflen - 1); + close(fd); + if (numwritten < 1) + ksft_exit_fail_msg("Write failed\n"); + return (unsigned int) numwritten; +} diff --git a/tools/testing/selftests/mm/vm_util.h b/tools/testing/selftests= /mm/vm_util.h index e9c4e24769c1..22c8805e0d7a 100644 --- a/tools/testing/selftests/mm/vm_util.h +++ b/tools/testing/selftests/mm/vm_util.h @@ -166,3 +166,5 @@ int unpoison_memory(unsigned long pfn); =20 #define PAGEMAP_PRESENT(ent) (((ent) & (1ull << 63)) !=3D 0) #define PAGEMAP_PFN(ent) ((ent) & ((1ull << 55) - 1)) + +unsigned int write_file(const char *path, const char *buf, size_t buflen); --=20 2.53.0