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Sun, 22 Mar 2026 23:11:12 -0400 X-MC-Unique: IGVfM-gtOxu5FC31Js5uWQ-1 X-Mimecast-MFC-AGG-ID: IGVfM-gtOxu5FC31Js5uWQ_1774235470 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (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 B2423195604F; Mon, 23 Mar 2026 03:11:09 +0000 (UTC) Received: from gmail.com (unknown [10.72.112.175]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 54AD71955D71; Mon, 23 Mar 2026 03:10:58 +0000 (UTC) Date: Mon, 23 Mar 2026 11:10:54 +0800 From: Chunyu Hu To: "David Hildenbrand (Arm)" Cc: akpm@linux-foundation.org, shuah@kernel.org, linux-mm@kvack.org, ljs@kernel.org, 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 Subject: Re: [PATCH v4 3/5] selftests/mm: move write_file helper to vm_util Message-ID: References: <20260319160656.1480279-1-chuhu@redhat.com> <20260319160656.1480279-4-chuhu@redhat.com> <78352e6f-fa40-41ee-b044-62f682f3ca43@kernel.org> MIME-Version: 1.0 In-Reply-To: <78352e6f-fa40-41ee-b044-62f682f3ca43@kernel.org> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 X-Mimecast-MFC-PROC-ID: Bj2MWj-bO0FtzGmOR02nO27MzB50wE0vQhipR3mlHxM_1774235470 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 18E4F40012 X-Stat-Signature: 9cp5ux3fiqgubbdxzbpjb4s1go64bniz X-Rspam-User: X-HE-Tag: 1774235476-755480 X-HE-Meta: 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 pEyu6/T+ J6Zi0nwQkZu3qZ0O7LI1pJnxekVOe2vRtifcL9hYNPyZz64CsUpgbytl9UtTRvkyXN1Cvh7wN0NAljlpiPIJs5PKG7igazdfIO9ngTmssG0LkrEpU3WfELmMatji0znXCa33q5Uv/F1IQbXAUeO4S/7VaOJUZ3/I8FM2xgOhNhiHcGbslr64nmpQp6PQOMSqBSbNQUEznNjQcOrRvTevmZXT70pqjddYF4iXPNXis7SrgfckqWVzkkFsxcNLuXfC0Y5rnQdaQbmiaFwY+lO5rOTV7qJcGOB87CqIjwQlveZF19Y7+fC/Q3Hu4oVhvvBQSq1lyJKzlD8idzTVsJS7sPyv/1jbUgC/uM2zT Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, Mar 19, 2026 at 10:48:38PM +0100, David Hildenbrand (Arm) wrote: > > > + > > +void write_file(const char *path, const char *buf, size_t buflen) > > +{ > > + int fd; > > + ssize_t numwritten; > > + > > + fd = open(path, O_WRONLY); > > + if (fd == -1) > > + ksft_exit_fail_msg("%s open failed: %s\n", path, strerror(errno)); > > + > > + numwritten = write(fd, buf, buflen - 1); > > + close(fd); > > + if (numwritten < 1) > > + ksft_exit_fail_msg("Write failed\n"); > I guess we could indeed test here easily for > > if (numwritten != buflen - 1) Looks like you are right. AI provided other questions on this helper, maybe I can append a patch in the series to do such robust improvement. > > But then, we don't really expect only partial writes to succeed here. > > Acked-by: David Hildenbrand (Arm) > > -- > Cheers, > > David >