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 E0B8CCA0EDC for ; Fri, 15 Aug 2025 02:41:26 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8A189900206; Thu, 14 Aug 2025 22:41:26 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8516A8E0002; Thu, 14 Aug 2025 22:41:26 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 740EE900206; Thu, 14 Aug 2025 22:41:26 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 62AE68E0002 for ; Thu, 14 Aug 2025 22:41:26 -0400 (EDT) Received: from smtpin29.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 3BF45118065 for ; Fri, 15 Aug 2025 02:41:26 +0000 (UTC) X-FDA: 83777440572.29.4651AFC Received: from out-178.mta0.migadu.com (out-178.mta0.migadu.com [91.218.175.178]) by imf20.hostedemail.com (Postfix) with ESMTP id 6A5C61C0006 for ; Fri, 15 Aug 2025 02:41:24 +0000 (UTC) Authentication-Results: imf20.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=mOpxZTSb; spf=pass (imf20.hostedemail.com: domain of ye.liu@linux.dev designates 91.218.175.178 as permitted sender) smtp.mailfrom=ye.liu@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1755225684; 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=waVzgAtOi12GgE5yS/99lkSoGQsnDE3UwmJZtXxGlEI=; b=WKsrqEnw220xFklSC+Y1IzEzLIBnopLlJ1ad7xsnCM/1QXKXzWaKx/1BMZtYGZcc8w/REn gAAbOgoGosBXWUtVyJqlaSY7CJsKmibkjpadERNwneRSD8gl4+FP5Ft257wK6x0OF+tptj OZQwPKLMqNEYAg549vpVWASshSLUsrI= ARC-Authentication-Results: i=1; imf20.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=mOpxZTSb; spf=pass (imf20.hostedemail.com: domain of ye.liu@linux.dev designates 91.218.175.178 as permitted sender) smtp.mailfrom=ye.liu@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1755225684; a=rsa-sha256; cv=none; b=1cwxDj1pYz1KQZYAUv027xacOuWkqn9gyrF02MeYqNzY5K1sk/5pOc/29nor98hc0YPDiI jIed4DWpbtMwy4GXyTjCNqNAKsJdct0jmVooUPz9MJIGkeuLvnLkg2IQUlZZSwZrWWd71p vGc6UtUkJI9CFr2L/PZ7t2bpMC3akSI= Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1755225682; h=from:from: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; bh=waVzgAtOi12GgE5yS/99lkSoGQsnDE3UwmJZtXxGlEI=; b=mOpxZTSbLfxNoXp5e2h13cpSn1859H5ulR05HsjEyQA5K+tfvtP5JtlCf5X2GxoErJr5sE OUTgM7JscK5L2uLEBj+jv2FfpktYyHI0SihUTRvqrkjh/S25sfz8qOj+AXqJiqAgD/FM21 bn0apTMTP65b6yIoSuCGHjV6S3jkVI8= Date: Fri, 15 Aug 2025 10:41:16 +0800 MIME-Version: 1.0 Subject: Re: [PATCH v2] mm/page_alloc: simplify lowmem_reserve max calculation To: Zi Yan Cc: Andrew Morton , Vlastimil Babka , Ye Liu , Johannes Weiner , Suren Baghdasaryan , Michal Hocko , Brendan Jackman , linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20250815023500.36893-1-ye.liu@linux.dev> Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Ye Liu In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Stat-Signature: nbobt5br1wuh5ktnzhah73ra1uj8j44n X-Rspam-User: X-Rspamd-Queue-Id: 6A5C61C0006 X-Rspamd-Server: rspam05 X-HE-Tag: 1755225684-536618 X-HE-Meta: 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 qiGXMLla MCNMnPK1AHkbS2y8FrWhhjMBuLZbHNgff5+4HUTlt039H0uMSZNjM40ata/dQX/HM/b5d4TplEHKQ6ML64vAs6xSE32ane8TWmkjE1DK64eTHT0WPKQzYnICDVAv7PTXvBEYRPWYRLfCw/IKbbMXY6PuEJQ1e0o5PjbFSCpVAxu2tlHM317dVTtbXDV9eQij0k7j81wrz7XPIXiL/R4clYNDWE0B8F2NWtBs8QV6kW8ZpW+comU5BZt1mLrbl3m4zRkP0DnixONANvRoSbbB3cABJkx4iPrwt57ACHXCyBuFhEdxh67Oki/yiIZokJ0+Mzi/+ScT0nFa3C26LbxiMDtMTdKCcqmAW2ckSSKNj6G7G+qm4d15BCcb4fARtEdUqYCuQ 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: 在 2025/8/15 10:36, Zi Yan 写道: > On 14 Aug 2025, at 22:34, Ye Liu wrote: > >> From: Ye Liu >> >> Use max() to find the maximum lowmem_reserve value and min_t() to >> cap it to managed_pages in calculate_totalreserve_pages(), instead >> of open-coding the comparisons. No functional change. >> >> Signed-off-by: Ye Liu >> Acked-by: Johannes Weiner >> Acked-by: Zi Yan >> >> Changes in v2: >> - Drop unnecessary braces >> - Replace "if (max > managed_pages)" with min_t() >> - Link to v1:https://lore.kernel.org/all/20250814090053.22241-1-ye.liu@linux.dev/ >> --- >> mm/page_alloc.c | 9 +++------ >> 1 file changed, 3 insertions(+), 6 deletions(-) >> >> diff --git a/mm/page_alloc.c b/mm/page_alloc.c >> index 64872214bc7d..2617fd2f4b73 100644 >> --- a/mm/page_alloc.c >> +++ b/mm/page_alloc.c >> @@ -6235,16 +6235,13 @@ static void calculate_totalreserve_pages(void) >> unsigned long managed_pages = zone_managed_pages(zone); >> >> /* Find valid and maximum lowmem_reserve in the zone */ >> - for (j = i; j < MAX_NR_ZONES; j++) { >> - if (zone->lowmem_reserve[j] > max) >> - max = zone->lowmem_reserve[j]; >> - } >> + for (j = i; j < MAX_NR_ZONES; j++) >> + max = max(max, zone->lowmem_reserve[j]); >> >> /* we treat the high watermark as reserved pages. */ >> max += high_wmark_pages(zone); >> >> - if (max > managed_pages) >> - max = managed_pages; >> + min_t(unsigned long, max, managed_pages); > > Should be > > max = min_t(unsigned long, max, managed_pages); > > ;) Haha I forgot to git add after I modified it ;) > >> >> pgdat->totalreserve_pages += max; >> >> -- >> 2.43.0 > > > Best Regards, > Yan, Zi -- Thanks, Ye Liu