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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 C3BD4C47082 for ; Mon, 31 May 2021 09:40:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 97656611AC for ; Mon, 31 May 2021 09:40:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231211AbhEaJlq (ORCPT ); Mon, 31 May 2021 05:41:46 -0400 Received: from smtp-out2.suse.de ([195.135.220.29]:48588 "EHLO smtp-out2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230520AbhEaJlm (ORCPT ); Mon, 31 May 2021 05:41:42 -0400 Received: from imap.suse.de (imap-alt.suse-dmz.suse.de [192.168.254.47]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 118A81FD2E; Mon, 31 May 2021 09:40:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1622454002; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc; bh=B6vJGCeBItbMKITVN84NRMnJUjGJul8S8oWcxChU3SQ=; b=Gk8mfx1UTwzLBSB5QB8QSdZ1pR1CtOobl5+Km6YbI6WMo0AY3xdBEqQVnac01UnL3Bc3cF fEWj3bEyA0WLQ3D3rwPB2+Cl+4E0kuiOocfphQYkwGp4LHZr5uK08z/LmCE+M6Px3AjZ/n V7SiHaYdhs2TlEHlID3K79ccrlQAtrw= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1622454002; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc; bh=B6vJGCeBItbMKITVN84NRMnJUjGJul8S8oWcxChU3SQ=; b=p3btLM6/sV9fM6QeKf3/rnQKKwnWLH+ki7770KlwF3qfTFXWwDjSAYAqF6NOxjP148+Og1 hZ98jnj393dZahAw== Received: from imap3-int (imap-alt.suse-dmz.suse.de [192.168.254.47]) by imap.suse.de (Postfix) with ESMTP id 4A461118DD; Mon, 31 May 2021 09:40:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1622454001; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc; bh=B6vJGCeBItbMKITVN84NRMnJUjGJul8S8oWcxChU3SQ=; b=UYCLo9SH2hEgfz5NPnVXejCb7vvH4k1px8oaEQe/dgcKXk56Xx7p7FAda2Sy0qnxXS3Crk aA0kwVjyB2jjW2sq6u5M1xD/SM13lWrlxE9wo0gIxOPSbUqjxJefgS8+8eAHlFihVhXVSc ORoLgEkQaK4p7YYkoOTkxzuz0R0V0OU= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1622454001; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc; bh=B6vJGCeBItbMKITVN84NRMnJUjGJul8S8oWcxChU3SQ=; b=DwZmGWx95oQ44tuUq/OKRpox3ty1G1XR4m7zqmku0fWcXu4iTP4kO3Jzaon3a/VRnj1cGK NGJY40Nu+2d4cdCw== Received: from director2.suse.de ([192.168.254.72]) by imap3-int with ESMTPSA id R0PJDvGutGD9XgAALh3uQQ (envelope-from ); Mon, 31 May 2021 09:40:01 +0000 From: Oscar Salvador To: Andrew Morton Cc: David Hildenbrand , Michal Hocko , Anshuman Khandual , Vlastimil Babka , Pavel Tatashin , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Oscar Salvador Subject: [PATCH] mm,memory_hotplug: Drop unneeded locking Date: Mon, 31 May 2021 11:39:58 +0200 Message-Id: <20210531093958.15021-1-osalvador@suse.de> X-Mailer: git-send-email 2.13.7 Authentication-Results: imap.suse.de; none X-Spamd-Result: default: False [1.00 / 100.00]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_GOOD(-0.10)[text/plain]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; RCPT_COUNT_SEVEN(0.00)[9]; MID_CONTAINS_FROM(1.00)[]; RCVD_NO_TLS_LAST(0.10)[]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; RCVD_COUNT_TWO(0.00)[2] Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently, memory-hotplug code takes zone's span_writelock and pgdat's resize_lock when resizing the node/zone's spanned pages via {move_pfn_range_to_zone(),remove_pfn_range_from_zone()} and when resizing node and zone's present pages via adjust_present_page_count(). These locks are also taken during the initialization of the system at boot time, where it protects parallel struct page initialization, but they should not really be needed in memory-hotplug where all operations are a) synchronized on device level and b) serialized by the mem_hotplug_lock lock. Signed-off-by: Oscar Salvador Acked-by: David Hildenbrand --- mm/memory_hotplug.c | 11 ----------- 1 file changed, 11 deletions(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 075b34803fec..9edbc57055bf 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -329,7 +329,6 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, unsigned long pfn; int nid = zone_to_nid(zone); - zone_span_writelock(zone); if (zone->zone_start_pfn == start_pfn) { /* * If the section is smallest section in the zone, it need @@ -362,7 +361,6 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, zone->spanned_pages = 0; } } - zone_span_writeunlock(zone); } static void update_pgdat_span(struct pglist_data *pgdat) @@ -424,10 +422,8 @@ void __ref remove_pfn_range_from_zone(struct zone *zone, clear_zone_contiguous(zone); - pgdat_resize_lock(zone->zone_pgdat, &flags); shrink_zone_span(zone, start_pfn, start_pfn + nr_pages); update_pgdat_span(pgdat); - pgdat_resize_unlock(zone->zone_pgdat, &flags); set_zone_contiguous(zone); } @@ -638,15 +634,10 @@ void __ref move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn, clear_zone_contiguous(zone); - /* TODO Huh pgdat is irqsave while zone is not. It used to be like that before */ - pgdat_resize_lock(pgdat, &flags); - zone_span_writelock(zone); if (zone_is_empty(zone)) init_currently_empty_zone(zone, start_pfn, nr_pages); resize_zone_range(zone, start_pfn, nr_pages); - zone_span_writeunlock(zone); resize_pgdat_range(pgdat, start_pfn, nr_pages); - pgdat_resize_unlock(pgdat, &flags); /* * Subsection population requires care in pfn_to_online_page(). @@ -739,9 +730,7 @@ void adjust_present_page_count(struct zone *zone, long nr_pages) unsigned long flags; zone->present_pages += nr_pages; - pgdat_resize_lock(zone->zone_pgdat, &flags); zone->zone_pgdat->node_present_pages += nr_pages; - pgdat_resize_unlock(zone->zone_pgdat, &flags); } int mhp_init_memmap_on_memory(unsigned long pfn, unsigned long nr_pages, -- 2.16.3