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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] Authentication-Results: imf26.hostedemail.com; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=Gk8mfx1U; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b="p3btLM6/"; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=UYCLo9SH; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=DwZmGWx9; spf=pass (imf26.hostedemail.com: domain of osalvador@suse.de designates 195.135.220.29 as permitted sender) smtp.mailfrom=osalvador@suse.de; dmarc=none X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 763A64202A07 X-Stat-Signature: t46ktf37mjk4jybwrcak4ar3awpcs43u X-HE-Tag: 1622453997-111598 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: 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 Acked-by: Michal Hocko --- 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,