From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 44AE8CD343F for ; Mon, 18 May 2026 23:35:58 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 71B666B0005; Mon, 18 May 2026 19:35:57 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6CC366B0088; Mon, 18 May 2026 19:35:57 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5E3A56B008C; Mon, 18 May 2026 19:35:57 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 4E6906B0005 for ; Mon, 18 May 2026 19:35:57 -0400 (EDT) Received: from smtpin28.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay08.hostedemail.com (Postfix) with ESMTP id EE254140809 for ; Mon, 18 May 2026 23:35:56 +0000 (UTC) X-FDA: 84782150712.28.7D20F6A Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf01.hostedemail.com (Postfix) with ESMTP id 4DDB54000D for ; Mon, 18 May 2026 23:35:55 +0000 (UTC) Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=HO2zsGaM; spf=pass (imf01.hostedemail.com: domain of akpm@linux-foundation.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1779147355; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=tSYf/5by7CSZvk31CpnT4CEOl9ZSbdictre/en4oKUY=; b=11aVBP46GJ2GWSyJQVbY1AnZz2jfvRFIFmj1ikcRyieaQ3kPxjA3tsaQ2PI6mt19tpYqx3 6vMAEeELc+0BnEP0c+jbvGn93vSbgzVpOy0hVH3LG7Xs7m+9nFP+OYTbCy+64rDTm8m6tZ 8DpfSn9QoELbUDTBdTqWCfvvX1UoncE= ARC-Authentication-Results: i=1; imf01.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=HO2zsGaM; spf=pass (imf01.hostedemail.com: domain of akpm@linux-foundation.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1779147355; a=rsa-sha256; cv=none; b=PIqX6VDgZsqdX8rVQl56BrVtw9468MG+BH3/clpyIgWhVyq1EpDPPgkkRugQy/kEBkqZRF i3rgtZehHm1UyuNpsWws0WxiYA8Ud2Rcl5V+T4Ycq3GPGpfWmJz10P93jTt1hK6c4LkwfT c5EAk7b2pe78vGldKAiIXNJuFiKdN9o= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 9AFFB60123; Mon, 18 May 2026 23:35:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0DDA3C2BCB7; Mon, 18 May 2026 23:35:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1779147354; bh=gVNHBOq1KiP8XHHPybiQcYnWomlkLg2qUtgXy+sjkWo=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=HO2zsGaMh+GlLpkSfYucUJmMiqmfPY7fejujsFrV1jhvFJXerI3iPl6LQri4+JRX7 ci76BMZG4gFP5Sf8BKyq12aG+0uTCIR+teHm7k+h/9hikvjY/pddVYcUb/hHCQ/kA2 OohZR+6aE89crWVGuVU4ArFCRp4A/CeHjvRgZxXg= Date: Mon, 18 May 2026 16:35:53 -0700 From: Andrew Morton To: Wei Yang Cc: Vineet Agarwal , david@kernel.org, ljs@kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] selftests/mm: check file initialization writes in split_huge_page_test Message-Id: <20260518163553.447a45c54a3d419b9bb916ca@linux-foundation.org> In-Reply-To: <20260515092211.qkmaxcofxwfdexld@master> References: <20260512074924.27721-1-agarwal.vineet2006@gmail.com> <20260515092211.qkmaxcofxwfdexld@master> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 4DDB54000D X-Rspam-User: X-Stat-Signature: sguas9rzw75s3dhkdhp6u8ojwcxaob1a X-HE-Tag: 1779147355-402904 X-HE-Meta: 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 RlM7d7r+ EnKua8L/j6Y8H6EEUU48H3drJOaiItq9EaaROt54rsAA0wXylqmPIz2fnz86kd75fHQzJiCFR/SxxNMvQ7dcuUxYlBrNPxwmheXmtGhopovbXCXUL0FzBkM2x8qEk/mF+lWCnXGza4AV9haJeAhBXdcXYE6/xIOuixQbA1WYG0TjkTtiO15uxCtkVTJCeOs6xrv9wEe0lLreVEtU/g20BSkodLD/FOIgrViQ0vVaCcwXwk0+5IbjIWU6GPrGoM5Qp7Jxj786LPBwq0sqvCjWgJHySRYLkjQLhzAUgn1X2KW9etruw4TBEMyEhJfzG7IZF3jh7d9DJE/FNR3zo0vzrEVMuZqO81u/nY2TTciS+HhEmKs0nHw1epmZEVMPR34sspr5nHF39+9c80+8XITYqJoyZfxYfgzpqUFzL Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri, 15 May 2026 09:22:11 +0000 Wei Yang wrote: > On Tue, May 12, 2026 at 01:19:24PM +0530, Vineet Agarwal wrote: > >create_pagecache_thp_and_fd() fills the backing file for the > >pagecache THP tests using repeated write() calls, but the return > >value is never checked. > > > >If a write fails or completes only partially, the test may continue > >with an incompletely initialized file and produce misleading results. > > > >Check the result of write() and fail the test if the expected number > >of bytes was not written. > > > >Signed-off-by: Vineet Agarwal > >--- > > tools/testing/selftests/mm/split_huge_page_test.c | 13 ++++++++++--- > > 1 file changed, 10 insertions(+), 3 deletions(-) > > > >diff --git a/tools/testing/selftests/mm/split_huge_page_test.c b/tools/testing/selftests/mm/split_huge_page_test.c > >index 500d07c4938b..eab69b0f59a0 100644 > >--- a/tools/testing/selftests/mm/split_huge_page_test.c > >+++ b/tools/testing/selftests/mm/split_huge_page_test.c > >@@ -609,9 +609,16 @@ static int create_pagecache_thp_and_fd(const char *testfile, size_t fd_size, > > assert(fd_size % sizeof(buf) == 0); > > for (i = 0; i < sizeof(buf); i++) > > buf[i] = (unsigned char)i; > >- for (i = 0; i < fd_size; i += sizeof(buf)) > >- write(*fd, buf, sizeof(buf)); > >- > >+ for (i = 0; i < fd_size; i += sizeof(buf)) { > >+ ssize_t written; > >+ > >+ written = write(*fd, buf, sizeof(buf)); > >+ if (written != sizeof(buf)) { > >+ ksft_perror("write testfile"); > >+ close(*fd); > >+ goto err_out_unlink; > > Maybe we can "goto err_out_close" and remove the close() here? AI review suggested the same: https://sashiko.dev/#/patchset/20260512074924.27721-1-agarwal.vineet2006%40gmail.com And it complained about the handling of short writes in the added code. > Apart from this, I found on error writing to /proc/sys/vm/drop_caches in below, > it just goto err_out_unlink, which left fd open. Not understanding - cab you please describe more completely? > How about fix that at the same time. > > Generally, the change look good. >