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 X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,URIBL_DBL_ABUSE_MALW, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 05B55C33CA1 for ; Wed, 5 Feb 2020 09:59:20 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id CD12421741 for ; Wed, 5 Feb 2020 09:59:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="uV7gF6bl" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CD12421741 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:Reply-To:List-Subscribe:List-Help: List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version: References:Message-ID:Subject:To:From:Date:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=LiCsxcURh06RitN3cfuYaR8TgYBUROLfXPPEUBEVZW8=; b=uV7gF6bl26LR3w KrK4hGtstLatGOEv8r08O/4gPvKWNljMoSZlWzJEb+sCyI9aRbsaOztoX+jwpOt0pELeKxzf1FqQW jafKQcZDdz+QNT1lISE5h866CXxWmrgU+hozxo7TgDaxhBaXVNu9OplSeq7n2GzCdT5f3kOgj6nyp 3ivmiVtvm7FWk8iOXa4k2ZU8PhhRUsDb2OEOgVM/hBR+m//eb/6PJ/1Vi+VDCY9xTrveHeIpbna66 zcPYboR8giNaeQY3sUmLYrUMmJwUCrt6G8BoHfpRshq3QdMIg+cI+SvN3lS8pmiw4Vdspcc0g62QO Z9FnHnA/YvORVPgCKtkw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1izHSk-000692-Cl; Wed, 05 Feb 2020 09:59:14 +0000 Received: from mga02.intel.com ([134.134.136.20]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1izHSh-00068e-Co for linux-arm-kernel@lists.infradead.org; Wed, 05 Feb 2020 09:59:12 +0000 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 05 Feb 2020 01:59:10 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,405,1574150400"; d="scan'208";a="343395725" Received: from richard.sh.intel.com (HELO localhost) ([10.239.159.54]) by fmsmga001.fm.intel.com with ESMTP; 05 Feb 2020 01:59:07 -0800 Date: Wed, 5 Feb 2020 17:59:24 +0800 From: Wei Yang To: David Hildenbrand Subject: Re: [PATCH v6 08/10] mm/memory_hotplug: Don't check for "all holes" in shrink_zone_span() Message-ID: <20200205095924.GC24162@richard> References: <20191006085646.5768-1-david@redhat.com> <20191006085646.5768-9-david@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20191006085646.5768-9-david@redhat.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200205_015911_486050_03DE9E5F X-CRM114-Status: GOOD ( 16.37 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Wei Yang Cc: linux-s390@vger.kernel.org, Michal Hocko , linux-ia64@vger.kernel.org, Pavel Tatashin , linux-sh@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Wei Yang , Andrew Morton , linuxppc-dev@lists.ozlabs.org, Dan Williams , linux-arm-kernel@lists.infradead.org, Oscar Salvador Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Sun, Oct 06, 2019 at 10:56:44AM +0200, David Hildenbrand wrote: >If we have holes, the holes will automatically get detected and removed >once we remove the next bigger/smaller section. The extra checks can >go. > >Cc: Andrew Morton >Cc: Oscar Salvador >Cc: Michal Hocko >Cc: David Hildenbrand >Cc: Pavel Tatashin >Cc: Dan Williams >Cc: Wei Yang >Signed-off-by: David Hildenbrand >--- > mm/memory_hotplug.c | 34 +++++++--------------------------- > 1 file changed, 7 insertions(+), 27 deletions(-) > >diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c >index f294918f7211..8dafa1ba8d9f 100644 >--- a/mm/memory_hotplug.c >+++ b/mm/memory_hotplug.c >@@ -393,6 +393,9 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, > if (pfn) { > zone->zone_start_pfn = pfn; > zone->spanned_pages = zone_end_pfn - pfn; >+ } else { >+ zone->zone_start_pfn = 0; >+ zone->spanned_pages = 0; > } > } else if (zone_end_pfn == end_pfn) { > /* >@@ -405,34 +408,11 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, > start_pfn); > if (pfn) > zone->spanned_pages = pfn - zone_start_pfn + 1; >+ else { >+ zone->zone_start_pfn = 0; >+ zone->spanned_pages = 0; >+ } > } If it is me, I would like to take out these two similar logic out. For example: if () { } else if () { } else { goto out; } /* The zone has no valid section */ if (!pfn) { zone->zone_start_pfn = 0; zone->spanned_pages = 0; } out: zone_span_writeunlock(zone); Well, this is just my personal taste :-) >- >- /* >- * The section is not biggest or smallest mem_section in the zone, it >- * only creates a hole in the zone. So in this case, we need not >- * change the zone. But perhaps, the zone has only hole data. Thus >- * it check the zone has only hole or not. >- */ >- pfn = zone_start_pfn; >- for (; pfn < zone_end_pfn; pfn += PAGES_PER_SUBSECTION) { >- if (unlikely(!pfn_to_online_page(pfn))) >- continue; >- >- if (page_zone(pfn_to_page(pfn)) != zone) >- continue; >- >- /* Skip range to be removed */ >- if (pfn >= start_pfn && pfn < end_pfn) >- continue; >- >- /* If we find valid section, we have nothing to do */ >- zone_span_writeunlock(zone); >- return; >- } >- >- /* The zone has no valid section */ >- zone->zone_start_pfn = 0; >- zone->spanned_pages = 0; > zone_span_writeunlock(zone); > } > >-- >2.21.0 -- Wei Yang Help you, Help me _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel