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]) by smtp.lore.kernel.org (Postfix) with ESMTP id 15F7BC3ABC9 for ; Wed, 7 May 2025 18:07:06 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9D2846B00A4; Wed, 7 May 2025 14:07:05 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9821B6B00A6; Wed, 7 May 2025 14:07:05 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 86DDC6B00A7; Wed, 7 May 2025 14:07:05 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 6935B6B00A4 for ; Wed, 7 May 2025 14:07:05 -0400 (EDT) Received: from smtpin23.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id A161F1CF6D8 for ; Wed, 7 May 2025 18:07:05 +0000 (UTC) X-FDA: 83416893210.23.47F2070 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf10.hostedemail.com (Postfix) with ESMTP id C5628C001A for ; Wed, 7 May 2025 18:07:03 +0000 (UTC) Authentication-Results: imf10.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=K5++BXeN; dmarc=none; spf=pass (imf10.hostedemail.com: domain of akpm@linux-foundation.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1746641223; a=rsa-sha256; cv=none; b=LPe+/PArZleX6RJey6chGb/WHJ2mEE2MWaYZNCDMEJv8Uli4XJnZ7+Usw8twblhtX7Vk2y AldiIiPYYxDr022lOGhiBN1c3o2eQ9wI0RsU21Ey2cTTRs9kJnYj00Tv3YdGElNrNPoEgz HyGyHxxWoaD/CbHiKGDs8nqxTg/lg6U= ARC-Authentication-Results: i=1; imf10.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=K5++BXeN; dmarc=none; spf=pass (imf10.hostedemail.com: domain of akpm@linux-foundation.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1746641223; 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=TrkzbarrKfc8xOtiCSR4NRHkd4peL8AHnn+iIYceWOg=; b=7Ju8yE+f99eibgPEMNgmVDTT2OfDvjAg70rx/gjiIXeHD5MsrrvsbBAbQ4s+/POozbldRl UAvqTWS9aJkqUuTxx5xtkvG1d18gzlejEv9v2Mjlm1YQkuabFucs/Aigve1KprEF6L6Zlv hTtflpo+tI7a+sRmgKBpsHFsI2stoHQ= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id E31F2629E4; Wed, 7 May 2025 18:07:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 47D44C4CEE9; Wed, 7 May 2025 18:07:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1746641222; bh=2fwDTg28OBa5HILWrLkhDJBJgNj50Lks4JnCyofJpQs=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=K5++BXeNwBIxl6SqvLgcDZwWslvdJ+7LLzUX68Oh+vyPz3totxw5WkLXqFNR4joeV iLF1WFoiI958lAWRjyHlKXUcqWWFE2SI3Gj5DxamfgzxByUSd3LVFsrrN38PDC+ThK SOZ/zGaIT0XzVRi7s2m58ahiBrouHzHLo6XdmxZ0= Date: Wed, 7 May 2025 11:07:01 -0700 From: Andrew Morton To: WangYuli Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, yuzhao@google.com, stevensd@chromium.org, kaleshsingh@google.com, zhanjun@uniontech.com, niecheng1@uniontech.com, guanwentao@uniontech.com, Matthew Wilcox Subject: Re: [PATCH] mm: vmscan: Avoid signedness error for GCC 5.4 Message-Id: <20250507110701.c2c135d3f4ed594b914da41b@linux-foundation.org> In-Reply-To: <74D5BC8AD7E5511A+13242b55-13e5-463a-9422-f863d58b6af6@uniontech.com> References: <85050791B887DC13+20250506160238.799984-1-wangyuli@uniontech.com> <20250506162438.91fffc7ef924d9653ed0f503@linux-foundation.org> <74D5BC8AD7E5511A+13242b55-13e5-463a-9422-f863d58b6af6@uniontech.com> 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: rspam10 X-Rspamd-Queue-Id: C5628C001A X-Stat-Signature: tnyxgxg15zoy8w8axwkif1yjkrysf8bm X-Rspam-User: X-HE-Tag: 1746641223-463710 X-HE-Meta: U2FsdGVkX18lBD+kgvB4C3tA1l0szlVvE2rzmr5ibafxCVDx/MIGH6ZlMGAkJ9O+kvp4/9LVMpObi0hScauw/eXkmhpnbXmNtqO1ST4MzrFpDCSX21y6LpTBK7qBGczzp9XcPNgsJNBnJ92xjU+2yAf7qWrmbvenEMOCEgxM3J6lV1AHlTSjPjHelqONGfMu5VuI7Ye3Wc62YyacokEdU2qFN3oHUioulhJ0H5cTsbWc1/+eHE8LhIcORQd7ARfiNlrT0lKHCSeFUhleVRf8m6ZA4Q78jOgClzWKuWmVz7JIjeh6iuw9Kw367BZ7HMcksdoWFcZSyf+X5Ux0VPUdB/3vz+pqvah2U7gfz6tAa9nhrIgyprmEka0vG+mz5lETyGXcn5N9yL0OccW3JdArrBac188va9yLCXxWk17/Ksa9cCq2m+lmO4DRtsO/chOllT1DN/ZIlr4jKY7aS1bsA79Xy90wqdKwA9PxyZwuQaDdATW9EwmxWyBO6ziRjf27H8ms7lrTP3sUTg7T6XQCli4ifeXBt9FwQRb5S3FMfxarJ6L4TYTtw6BvNQmdx+58BVVYyU/AhnFB7eo4QbW0VXIcO+pHItQdWSCgEDZjsOktxxdeOJeTL4hP0224J4Gurj5uH2j20XWhzfz5zLp53UOlVDBDWbhv0E0HABb+JgyQDy9bm7PfkuSu/LVNgLpB4NWL7N6gwKcHVcvrzc07hKfWIA73DzRwYvwBlHHpq3kcwb8V/x5fZGmTV2p3wZKQuySyTUUxuQHDQa69GXPMlilGTDSsY00IxPjY3KmNoqB3+V3WJByj6wFS7t58Q+OOHQEzfEXHKdijkBZJ2J/ySFmaDzrx3KT21RMT6NDATI3w5GKkott/+rrBShhesSZH8iXWdUgZs1YPKMJ3+fHCstF3EB9jXkwTS5H0UKOw9o8WbNmVBzihHu+bc1aYoH6eTDsWDMpemOwg5xkqc7N ggsdkO/Y uXZdcOz2XprhRjm/Ve/zWbUuYMG7j5FcmiUCrp23cCLfDTpjn07rng/AYlmqa+O9789xdWLnDTSxUEcgMfZGkyOEU1e5FnjSPHCOfMIMMlhegr+/LXyluUD6DuAjL1uMtMes1lqw5WjjIwDp0xIQK/oJ34W8jGD0uaXzSIxG2Hp0h8sZgSs+UmkAjdoXfkJeLI99hVuX4KipgngYpCmtoMo/ENc4yRNr8ELRosHav8i4fCgFbPR6FpwJkXWz/IJ2pHWaxhzWzY8X8vN/p42or0mgKX8Tw0Epl6GC1QmZCt/6pct6yLE4oaau2rA== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, 7 May 2025 12:06:11 +0800 WangYuli wrote: > Perhaps a possible approach for now could be to change this line to for > (i = tier % MAX_NR_TIERS; i <= min_t(int, tier, MAX_NR_TIERS - 1); i++) > {, which would allow us to keep the signed int type for the tier > variable itself. Sure. > Regarding the potential for a more comprehensive change in the future to > redefine all these "tier" variables and related ones as unsigned int, I > would be very grateful for your guidance on whether that's a direction > we should consider. `int' is a curse. Yes, we do this very frequently - we unthinkingly use a signed type for a naturally unsigned concept. Ths signed type spreads and spreads and the incorrect signage causes (small) problems in various places. By then it's a big mess trying to switch to an unsigned type. Oh well, we just battle on. We should at least be more vigilant about this when adding new things. hp2:/usr/src/25> grep "int nid" mm/*.c | wc -l 316 argh.