From 1b862aecfbd419cdc4553645bf86d07554279bed Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Thu, 6 Jul 2017 15:37:45 -0700 Subject: mm, memory_hotplug: get rid of is_zone_device_section Device memory hotplug hooks into regular memory hotplug only half way. It needs memory sections to track struct pages but there is no need/desire to associate those sections with memory blocks and export them to the userspace via sysfs because they cannot be onlined anyway. This is currently expressed by for_device argument to arch_add_memory which then makes sure to associate the given memory range with ZONE_DEVICE. register_new_memory then relies on is_zone_device_section to distinguish special memory hotplug from the regular one. While this works now, later patches in this series want to move __add_zone outside of arch_add_memory path so we have to come up with something else. Add want_memblock down the __add_pages path and use it to control whether the section->memblock association should be done. arch_add_memory then just trivially want memblock for everything but for_device hotplug. remove_memory_section doesn't need is_zone_device_section either. We can simply skip all the memblock specific cleanup if there is no memblock for the given section. This shouldn't introduce any functional change. Link: http://lkml.kernel.org/r/20170515085827.16474-5-mhocko@kernel.org Signed-off-by: Michal Hocko Tested-by: Dan Williams Acked-by: Vlastimil Babka Cc: Andi Kleen Cc: Andrea Arcangeli Cc: Balbir Singh Cc: Daniel Kiper Cc: David Rientjes Cc: Heiko Carstens Cc: Igor Mammedov Cc: Jerome Glisse Cc: Joonsoo Kim Cc: Martin Schwidefsky Cc: Mel Gorman Cc: Reza Arbab Cc: Tobias Regnery Cc: Toshi Kani Cc: Vitaly Kuznetsov Cc: Xishi Qiu Cc: Yasuaki Ishimatsu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memory_hotplug.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'mm') diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 6b6362819be2..c0147d3024eb 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -494,7 +494,7 @@ static int __meminit __add_zone(struct zone *zone, unsigned long phys_start_pfn) } static int __meminit __add_section(int nid, struct zone *zone, - unsigned long phys_start_pfn) + unsigned long phys_start_pfn, bool want_memblock) { int ret; @@ -511,6 +511,9 @@ static int __meminit __add_section(int nid, struct zone *zone, if (ret < 0) return ret; + if (!want_memblock) + return 0; + return register_new_memory(nid, __pfn_to_section(phys_start_pfn)); } @@ -521,7 +524,7 @@ static int __meminit __add_section(int nid, struct zone *zone, * add the new pages. */ int __ref __add_pages(int nid, struct zone *zone, unsigned long phys_start_pfn, - unsigned long nr_pages) + unsigned long nr_pages, bool want_memblock) { unsigned long i; int err = 0; @@ -549,7 +552,7 @@ int __ref __add_pages(int nid, struct zone *zone, unsigned long phys_start_pfn, } for (i = start_sec; i <= end_sec; i++) { - err = __add_section(nid, zone, section_nr_to_pfn(i)); + err = __add_section(nid, zone, section_nr_to_pfn(i), want_memblock); /* * EEXIST is finally dealt with by ioresource collision -- cgit v1.2.3