user/sven/linux.git/include/linux/mmzone.h, branch v4.19.43

mm, sched/numa: Remove remaining traces of NUMA rate-limiting

2018-10-09T06:30:51Z

Remove the leftover pglist_data::numabalancing_migrate_lock and its initialization, we stopped using this lock with: efaffc5e40ae ("mm, sched/numa: Remove rate-limiting of automatic NUMA balancing migration") [ mingo: Rewrote the changelog. ] Signed-off-by: Srikar Dronamraju Acked-by: Mel Gorman Cc: Linus Torvalds Cc: Linux-MM Cc: Peter Zijlstra Cc: Rik van Riel Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1538824999-31230-1-git-send-email-srikar@linux.vnet.ibm.com Signed-off-by: Ingo Molnar

mm, sched/numa: Remove rate-limiting of automatic NUMA balancing migration

2018-10-02T09:31:14Z

Rate limiting of page migrations due to automatic NUMA balancing was introduced to mitigate the worst-case scenario of migrating at high frequency due to false sharing or slowly ping-ponging between nodes. Since then, a lot of effort was spent on correctly identifying these pages and avoiding unnecessary migrations and the safety net may no longer be required. Jirka Hladky reported a regression in 4.17 due to a scheduler patch that avoids spreading STREAM tasks wide prematurely. However, once the task was properly placed, it delayed migrating the memory due to rate limiting. Increasing the limit fixed the problem for him. Currently, the limit is hard-coded and does not account for the real capabilities of the hardware. Even if an estimate was attempted, it would not properly account for the number of memory controllers and it could not account for the amount of bandwidth used for normal accesses. Rather than fudging, this patch simply eliminates the rate limiting. However, Jirka reports that a STREAM configuration using multiple processes achieved similar performance to 4.16. In local tests, this patch improved performance of STREAM relative to the baseline but it is somewhat machine-dependent. Most workloads show little or not performance difference implying that there is not a heavily reliance on the throttling mechanism and it is safe to remove. STREAM on 2-socket machine 4.19.0-rc5 4.19.0-rc5 numab-v1r1 noratelimit-v1r1 MB/sec copy 43298.52 ( 0.00%) 44673.38 ( 3.18%) MB/sec scale 30115.06 ( 0.00%) 31293.06 ( 3.91%) MB/sec add 32825.12 ( 0.00%) 34883.62 ( 6.27%) MB/sec triad 32549.52 ( 0.00%) 34906.60 ( 7.24% Signed-off-by: Mel Gorman Reviewed-by: Rik van Riel Acked-by: Peter Zijlstra Cc: Jirka Hladky Cc: Linus Torvalds Cc: Linux-MM Cc: Srikar Dronamraju Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20181001100525.29789-2-mgorman@techsingularity.net Signed-off-by: Ingo Molnar

mm: access zone->node via zone_to_nid() and zone_set_nid()

2018-08-22T17:52:45Z

zone->node is configured only when CONFIG_NUMA=y, so it is a good idea to have inline functions to access this field in order to avoid ifdef's in c files. Link: http://lkml.kernel.org/r/20180730101757.28058-3-osalvador@techadventures.net Signed-off-by: Pavel Tatashin Signed-off-by: Oscar Salvador Reviewed-by: Oscar Salvador Acked-by: Michal Hocko Acked-by: Vlastimil Babka Cc: Aaron Lu Cc: Dan Williams Cc: David Hildenbrand Cc: Joonsoo Kim Cc: Mel Gorman Cc: Pasha Tatashin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: remove zone_id() and make use of zone_idx() in is_dev_zone()

2018-08-22T17:52:45Z

is_dev_zone() is using zone_id() to check if the zone is ZONE_DEVICE. zone_id() looks pretty much the same as zone_idx(), and while the use of zone_idx() is quite spread in the kernel, zone_id() is only being used by is_dev_zone(). This patch removes zone_id() and makes is_dev_zone() use zone_idx() to check the zone, so we do not have two things with the same functionality around. Link: http://lkml.kernel.org/r/20180730133718.28683-1-osalvador@techadventures.net Signed-off-by: Oscar Salvador Acked-by: Michal Hocko Acked-by: Vlastimil Babka Reviewed-by: Pavel Tatashin Cc: Pasha Tatashin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/page_alloc: don't reserve ZONE_HIGHMEM for ZONE_MOVABLE request

2018-04-11T17:28:32Z

Freepage on ZONE_HIGHMEM doesn't work for kernel memory so it's not that important to reserve. When ZONE_MOVABLE is used, this problem would theorectically cause to decrease usable memory for GFP_HIGHUSER_MOVABLE allocation request which is mainly used for page cache and anon page allocation. So, fix it by setting 0 to sysctl_lowmem_reserve_ratio[ZONE_HIGHMEM]. And, defining sysctl_lowmem_reserve_ratio array by MAX_NR_ZONES - 1 size makes code complex. For example, if there is highmem system, following reserve ratio is activated for *NORMAL ZONE* which would be easyily misleading people. #ifdef CONFIG_HIGHMEM 32 #endif This patch also fixes this situation by defining sysctl_lowmem_reserve_ratio array by MAX_NR_ZONES and place "#ifdef" to right place. Link: http://lkml.kernel.org/r/1504672525-17915-1-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Joonsoo Kim Reviewed-by: Aneesh Kumar K.V Acked-by: Vlastimil Babka Tested-by: Tony Lindgren Cc: Michal Hocko Cc: Vlastimil Babka Cc: Mel Gorman Cc: Johannes Weiner Cc: "Aneesh Kumar K . V" Cc: Minchan Kim Cc: Rik van Riel Cc: Laura Abbott Cc: Marek Szyprowski Cc: Michal Nazarewicz Cc: Russell King Cc: Will Deacon Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: introduce NR_INDIRECTLY_RECLAIMABLE_BYTES

2018-04-11T17:28:29Z

Patch series "indirectly reclaimable memory", v2. This patchset introduces the concept of indirectly reclaimable memory and applies it to fix the issue of when a big number of dentries with external names can significantly affect the MemAvailable value. This patch (of 3): Introduce a concept of indirectly reclaimable memory and adds the corresponding memory counter and /proc/vmstat item. Indirectly reclaimable memory is any sort of memory, used by the kernel (except of reclaimable slabs), which is actually reclaimable, i.e. will be released under memory pressure. The counter is in bytes, as it's not always possible to count such objects in pages. The name contains BYTES by analogy to NR_KERNEL_STACK_KB. Link: http://lkml.kernel.org/r/20180305133743.12746-2-guro@fb.com Signed-off-by: Roman Gushchin Reviewed-by: Andrew Morton Cc: Alexander Viro Cc: Michal Hocko Cc: Johannes Weiner Cc: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm, page_alloc: wakeup kcompactd even if kswapd cannot free more memory

2018-04-06T04:36:27Z

Kswapd will not wakeup if per-zone watermarks are not failing or if too many previous attempts at background reclaim have failed. This can be true if there is a lot of free memory available. For high- order allocations, kswapd is responsible for waking up kcompactd for background compaction. If the zone is not below its watermarks or reclaim has recently failed (lots of free memory, nothing left to reclaim), kcompactd does not get woken up. When __GFP_DIRECT_RECLAIM is not allowed, allow kcompactd to still be woken up even if kswapd will not reclaim. This allows high-order allocations, such as thp, to still trigger background compaction even when the zone has an abundance of free memory. Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1803111659420.209721@chino.kir.corp.google.com Signed-off-by: David Rientjes Acked-by: Vlastimil Babka Cc: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: disable interrupts while initializing deferred pages

2018-04-06T04:36:24Z

Vlastimil Babka reported about a window issue during which when deferred pages are initialized, and the current version of on-demand initialization is finished, allocations may fail. While this is highly unlikely scenario, since this kind of allocation request must be large, and must come from interrupt handler, we still want to cover it. We solve this by initializing deferred pages with interrupts disabled, and holding node_size_lock spin lock while pages in the node are being initialized. The on-demand deferred page initialization that comes later will use the same lock, and thus synchronize with deferred_init_memmap(). It is unlikely for threads that initialize deferred pages to be interrupted. They run soon after smp_init(), but before modules are initialized, and long before user space programs. This is why there is no adverse effect of having these threads running with interrupts disabled. [pasha.tatashin@oracle.com: v6] Link: http://lkml.kernel.org/r/20180313182355.17669-2-pasha.tatashin@oracle.com Link: http://lkml.kernel.org/r/20180309220807.24961-2-pasha.tatashin@oracle.com Signed-off-by: Pavel Tatashin Reviewed-by: Andrew Morton Cc: Steven Sistare Cc: Daniel Jordan Cc: Masayoshi Mizuma Cc: Michal Hocko Cc: Catalin Marinas Cc: AKASHI Takahiro Cc: Gioh Kim Cc: Heiko Carstens Cc: Yaowei Bai Cc: Wei Yang Cc: Paul Burton Cc: Miles Chen Cc: Vlastimil Babka Cc: Mel Gorman Cc: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

x86/mm/32: Remove unused node_memmap_size_bytes() & CONFIG_NEED_NODE_MEMMAP_SIZE logic

2018-03-27T06:45:02Z

node_memmap_size_bytes() has been unused since the v3.9 kernel, so remove it. Signed-off-by: David Rientjes Cc: Dave Hansen Cc: Laura Abbott Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-mm@kvack.org Fixes: f03574f2d5b2 ("x86-32, mm: Rip out x86_32 NUMA remapping code") Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1803262325540.256524@chino.kir.corp.google.com Signed-off-by: Ingo Molnar

include/linux/mmzone.h: fix explanation of lower bits in the SPARSEMEM mem_map pointer

2018-02-01T01:18:39Z

The comment is confusing. On the one hand, it refers to 32-bit alignment (struct page alignment on 32-bit platforms), but this would only guarantee that the 2 lowest bits must be zero. On the other hand, it claims that at least 3 bits are available, and 3 bits are actually used. This is not broken, because there is a stronger alignment guarantee, just less obvious. Let's fix the comment to make it clear how many bits are available and why. Although memmap arrays are allocated in various places, the resulting pointer is encoded eventually, so I am adding a BUG_ON() here to enforce at runtime that all expected bits are indeed available. I have also added a BUILD_BUG_ON to check that PFN_SECTION_SHIFT is sufficient, because this part of the calculation can be easily checked at build time. [ptesarik@suse.com: v2] Link: http://lkml.kernel.org/r/20180125100516.589ea6af@ezekiel.suse.cz Link: http://lkml.kernel.org/r/20180119080908.3a662e6f@ezekiel.suse.cz Signed-off-by: Petr Tesarik Acked-by: Michal Hocko Cc: Vlastimil Babka Cc: Mel Gorman Cc: Johannes Weiner Cc: Kemi Wang Cc: YASUAKI ISHIMATSU Cc: Andrey Ryabinin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds