linux/mm/memory_hotplug.c, branch v4.8

mem-hotplug: use nodes that contain memory as mask in new_node_page()

2016-09-28T23:19:02Z

9bb627be47a5 ("mem-hotplug: don't clear the only node in new_node_page()") prevents allocating from an empty nodemask, but as David points out, it is still wrong. As node_online_map may include memoryless nodes, only allocating from these nodes is meaningless. This patch uses node_states[N_MEMORY] mask to prevent the above case. Fixes: 9bb627be47a5 ("mem-hotplug: don't clear the only node in new_node_page()") Fixes: 394e31d2ceb4 ("mem-hotplug: alloc new page from a nearest neighbor node when mem-offline") Link: http://lkml.kernel.org/r/1474447117.28370.6.camel@TP420 Signed-off-by: Li Zhong Suggested-by: David Rientjes Acked-by: Vlastimil Babka Cc: Michal Hocko Cc: John Allen Cc: Xishi Qiu Cc: Joonsoo Kim Cc: Naoya Horiguchi Cc: Tetsuo Handa Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mem-hotplug: don't clear the only node in new_node_page()

2016-09-19T22:36:16Z

Commit 394e31d2ceb4 ("mem-hotplug: alloc new page from a nearest neighbor node when mem-offline") introduced new_node_page() for memory hotplug. In new_node_page(), the nid is cleared before calling __alloc_pages_nodemask(). But if it is the only node of the system, and the first round allocation fails, it will not be able to get memory from an empty nodemask, and will trigger oom. The patch checks whether it is the last node on the system, and if it is, then don't clear the nid in the nodemask. Fixes: 394e31d2ceb4 ("mem-hotplug: alloc new page from a nearest neighbor node when mem-offline") Link: http://lkml.kernel.org/r/1473044391.4250.19.camel@TP420 Signed-off-by: Li Zhong Reported-by: John Allen Acked-by: Vlastimil Babka Cc: Xishi Qiu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/memory_hotplug.c: initialize per_cpu_nodestats for hotadded pgdats

2016-08-11T23:58:14Z

The following oops occurs after a pgdat is hotadded: Unable to handle kernel paging request for data at address 0x00c30001 Faulting instruction address: 0xc00000000022f8f4 Oops: Kernel access of bad area, sig: 11 [#1] SMP NR_CPUS=2048 NUMA pSeries Modules linked in: ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 ipt_REJECT nf_reject_ipv4 xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw iptable_filter nls_utf8 isofs sg virtio_balloon uio_pdrv_genirq uio ip_tables xfs libcrc32c sr_mod cdrom sd_mod virtio_net ibmvscsi scsi_transport_srp virtio_pci virtio_ring virtio dm_mirror dm_region_hash dm_log dm_mod CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 4.8.0-rc1-device #110 task: c000000000ef3080 task.stack: c000000000f6c000 NIP: c00000000022f8f4 LR: c00000000022f948 CTR: 0000000000000000 REGS: c000000000f6fa50 TRAP: 0300 Tainted: G W (4.8.0-rc1-device) MSR: 800000010280b033 CR: 84002028 XER: 20000000 CFAR: d000000001d2013c DAR: 0000000000c30001 DSISR: 40000000 SOFTE: 0 NIP refresh_cpu_vm_stats+0x1a4/0x2f0 LR refresh_cpu_vm_stats+0x1f8/0x2f0 Call Trace: refresh_cpu_vm_stats+0x1f8/0x2f0 (unreliable) Add per_cpu_nodestats initialization to the hotplug codepath. Link: http://lkml.kernel.org/r/1470931473-7090-1-git-send-email-arbab@linux.vnet.ibm.com Signed-off-by: Reza Arbab Cc: Mel Gorman Cc: Paul Mackerras Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mem-hotplug: alloc new page from a nearest neighbor node when mem-offline

2016-07-28T23:07:41Z

If we offline a node, alloc the new page from a nearest neighbor node instead of the current node or other remote nodes, because re-migrate is a waste of time and the distance of the remote nodes is often very large. Also use GFP_HIGHUSER_MOVABLE to alloc new page if the zone is movable zone or highmem zone. Link: http://lkml.kernel.org/r/5795E18B.5060302@huawei.com Signed-off-by: Xishi Qiu Cc: Joonsoo Kim Cc: Vlastimil Babka Cc: Naoya Horiguchi Cc: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm, vmscan: simplify the logic deciding whether kswapd sleeps

2016-07-28T23:07:41Z

kswapd goes through some complex steps trying to figure out if it should stay awake based on the classzone_idx and the requested order. It is unnecessarily complex and passes in an invalid classzone_idx to balance_pgdat(). What matters most of all is whether a larger order has been requsted and whether kswapd successfully reclaimed at the previous order. This patch irons out the logic to check just that and the end result is less headache inducing. Link: http://lkml.kernel.org/r/1467970510-21195-10-git-send-email-mgorman@techsingularity.net Signed-off-by: Mel Gorman Acked-by: Johannes Weiner Acked-by: Vlastimil Babka Cc: Hillf Danton Cc: Joonsoo Kim Cc: Michal Hocko Cc: Minchan Kim Cc: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm, vmscan: move LRU lists to node

2016-07-28T23:07:41Z

This moves the LRU lists from the zone to the node and related data such as counters, tracing, congestion tracking and writeback tracking. Unfortunately, due to reclaim and compaction retry logic, it is necessary to account for the number of LRU pages on both zone and node logic. Most reclaim logic is based on the node counters but the retry logic uses the zone counters which do not distinguish inactive and active sizes. It would be possible to leave the LRU counters on a per-zone basis but it's a heavier calculation across multiple cache lines that is much more frequent than the retry checks. Other than the LRU counters, this is mostly a mechanical patch but note that it introduces a number of anomalies. For example, the scans are per-zone but using per-node counters. We also mark a node as congested when a zone is congested. This causes weird problems that are fixed later but is easier to review. In the event that there is excessive overhead on 32-bit systems due to the nodes being on LRU then there are two potential solutions 1. Long-term isolation of highmem pages when reclaim is lowmem When pages are skipped, they are immediately added back onto the LRU list. If lowmem reclaim persisted for long periods of time, the same highmem pages get continually scanned. The idea would be that lowmem keeps those pages on a separate list until a reclaim for highmem pages arrives that splices the highmem pages back onto the LRU. It potentially could be implemented similar to the UNEVICTABLE list. That would reduce the skip rate with the potential corner case is that highmem pages have to be scanned and reclaimed to free lowmem slab pages. 2. Linear scan lowmem pages if the initial LRU shrink fails This will break LRU ordering but may be preferable and faster during memory pressure than skipping LRU pages. Link: http://lkml.kernel.org/r/1467970510-21195-4-git-send-email-mgorman@techsingularity.net Signed-off-by: Mel Gorman Acked-by: Johannes Weiner Acked-by: Vlastimil Babka Cc: Hillf Danton Cc: Joonsoo Kim Cc: Michal Hocko Cc: Minchan Kim Cc: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

memory-hotplug: more general validation of zone during online

2016-07-26T23:19:19Z

When memory is onlined, we are only able to rezone from ZONE_MOVABLE to ZONE_KERNEL, or from (ZONE_MOVABLE - 1) to ZONE_MOVABLE. To be more flexible, use the following criteria instead; to online memory from zone X into zone Y, * Any zones between X and Y must be unused. * If X is lower than Y, the onlined memory must lie at the end of X. * If X is higher than Y, the onlined memory must lie at the start of X. Add zone_can_shift() to make this determination. Link: http://lkml.kernel.org/r/1462816419-4479-3-git-send-email-arbab@linux.vnet.ibm.com Signed-off-by: Reza Arbab Reviewd-by: Yasuaki Ishimatsu Cc: Greg Kroah-Hartman Cc: Daniel Kiper Cc: Dan Williams Cc: Vlastimil Babka Cc: Tang Chen Cc: Joonsoo Kim Cc: David Vrabel Cc: Vitaly Kuznetsov Cc: David Rientjes Cc: Andrew Banman Cc: Chen Yucong Cc: Yasunori Goto Cc: Zhang Zhen Cc: Shaohua Li Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

memory-hotplug: add move_pfn_range()

2016-07-26T23:19:19Z

Add move_pfn_range(), a wrapper to call move_pfn_range_left() or move_pfn_range_right(). No functional change. This will be utilized by a later patch. Link: http://lkml.kernel.org/r/1462816419-4479-2-git-send-email-arbab@linux.vnet.ibm.com Signed-off-by: Reza Arbab Reviewed-by: Yasuaki Ishimatsu Cc: Greg Kroah-Hartman Cc: Daniel Kiper Cc: Dan Williams Cc: Vlastimil Babka Cc: Tang Chen Cc: Joonsoo Kim Cc: David Vrabel Cc: Vitaly Kuznetsov Cc: David Rientjes Cc: Andrew Banman Cc: Chen Yucong Cc: Yasunori Goto Cc: Zhang Zhen Cc: Shaohua Li Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: fix section mismatch warning

2016-05-27T22:23:32Z

The register_page_bootmem_info_node() function needs to be marked __init in order to avoid a new warning introduced by commit f65e91df25aa ("mm: use early_pfn_to_nid in register_page_bootmem_info_node"). Otherwise you'll get a warning about how a non-init function calls early_pfn_to_nid (which is __meminit) Cc: Yang Shi Cc: Andrew Morton Signed-off-by: Linus Torvalds

mm: use early_pfn_to_nid in register_page_bootmem_info_node

2016-05-27T21:49:37Z

register_page_bootmem_info_node() is invoked in mem_init(), so it will be called before page_alloc_init_late() if DEFERRED_STRUCT_PAGE_INIT is enabled. But, pfn_to_nid() depends on memmap which won't be fully setup until page_alloc_init_late() is done, so replace pfn_to_nid() by early_pfn_to_nid(). Link: http://lkml.kernel.org/r/1464210007-30930-1-git-send-email-yang.shi@linaro.org Signed-off-by: Yang Shi Cc: Mel Gorman Cc: Joonsoo Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds