linux/mm/compaction.c, branch v3.10.2

mm: add & use zone_end_pfn() and zone_spans_pfn()

2013-02-24T01:50:20Z

Add 2 helpers (zone_end_pfn() and zone_spans_pfn()) to reduce code duplication. This also switches to using them in compaction (where an additional variable needed to be renamed), page_alloc, vmstat, memory_hotplug, and kmemleak. Note that in compaction.c I avoid calling zone_end_pfn() repeatedly because I expect at some point the sycronization issues with start_pfn & spanned_pages will need fixing, either by actually using the seqlock or clever memory barrier usage. Signed-off-by: Cody P Schafer Cc: David Hansen Cc: Catalin Marinas Cc: Johannes Weiner Cc: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: remove offlining arg to migrate_pages

2013-02-24T01:50:19Z

No functional change, but the only purpose of the offlining argument to migrate_pages() etc, was to ensure that __unmap_and_move() could migrate a KSM page for memory hotremove (which took ksm_thread_mutex) but not for other callers. Now all cases are safe, remove the arg. Signed-off-by: Hugh Dickins Cc: Rik van Riel Cc: Petr Holasek Cc: Andrea Arcangeli Cc: Izik Eidus Cc: Gerald Schaefer Cc: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: remove MIGRATE_ISOLATE check in hotpath

2013-02-24T01:50:15Z

Several functions test MIGRATE_ISOLATE and some of those are hotpath but MIGRATE_ISOLATE is used only if we enable CONFIG_MEMORY_ISOLATION(ie, CMA, memory-hotplug and memory-failure) which are not common config option. So let's not add unnecessary overhead and code when we don't enable CONFIG_MEMORY_ISOLATION. Signed-off-by: Minchan Kim Cc: KOSAKI Motohiro Acked-by: Michal Nazarewicz Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: compaction: make __compact_pgdat() and compact_pgdat() return void

2013-02-24T01:50:10Z

These functions always return 0. Formalise this. Cc: Jason Liu Cc: KAMEZAWA Hiroyuki Cc: Mel Gorman Cc: Minchan Kim Cc: Rik van Riel Acked-by: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: compaction: do not accidentally skip pageblocks in the migrate scanner

2013-02-24T01:50:10Z

Compaction uses the ALIGN macro incorrectly with the migrate scanner by adding pageblock_nr_pages to a PFN. It happened to work when initially implemented as the starting PFN was also aligned but with caching restarts and isolating in smaller chunks this is no longer always true. The impact is that the migrate scanner scans outside its current pageblock. As pfn_valid() is still checked properly it does not cause any failure and the impact of the bug is that in some cases it will scan more than necessary when it crosses a page boundary but by no more than COMPACT_CLUSTER_MAX. It is highly unlikely this is even measurable but it's still wrong so this patch addresses the problem. Signed-off-by: Mel Gorman Reviewed-by: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: compaction: partially revert capture of suitable high-order page

2013-01-11T22:54:56Z

Eric Wong reported on 3.7 and 3.8-rc2 that ppoll() got stuck when waiting for POLLIN on a local TCP socket. It was easier to trigger if there was disk IO and dirty pages at the same time and he bisected it to commit 1fb3f8ca0e92 ("mm: compaction: capture a suitable high-order page immediately when it is made available"). The intention of that patch was to improve high-order allocations under memory pressure after changes made to reclaim in 3.6 drastically hurt THP allocations but the approach was flawed. For Eric, the problem was that page->pfmemalloc was not being cleared for captured pages leading to a poor interaction with swap-over-NFS support causing the packets to be dropped. However, I identified a few more problems with the patch including the fact that it can increase contention on zone->lock in some cases which could result in async direct compaction being aborted early. In retrospect the capture patch took the wrong approach. What it should have done is mark the pageblock being migrated as MIGRATE_ISOLATE if it was allocating for THP and avoided races that way. While the patch was showing to improve allocation success rates at the time, the benefit is marginal given the relative complexity and it should be revisited from scratch in the context of the other reclaim-related changes that have taken place since the patch was first written and tested. This patch partially reverts commit 1fb3f8ca0e92 ("mm: compaction: capture a suitable high-order page immediately when it is made available"). Reported-and-tested-by: Eric Wong Tested-by: Eric Dumazet Cc: Signed-off-by: Mel Gorman Cc: David Miller Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: compaction: fix echo 1 > compact_memory return error issue

2013-01-11T22:54:54Z

when run the folloing command under shell, it will return error sh/$ echo 1 > /proc/sys/vm/compact_memory sh/$ sh: write error: Bad address After strace, I found the following log: ... write(1, "1\n", 2) = 3 write(1, "", 4294967295) = -1 EFAULT (Bad address) write(2, "echo: write error: Bad address\n", 31echo: write error: Bad address ) = 31 This tells system return 3(COMPACT_COMPLETE) after write data to compact_memory. The fix is to make the system just return 0 instead 3(COMPACT_COMPLETE) from sysctl_compaction_handler after compaction_nodes finished. Signed-off-by: Jason Liu Suggested-by: David Rientjes Acked-by: Mel Gorman Cc: Rik van Riel Cc: Minchan Kim Cc: KAMEZAWA Hiroyuki Acked-by: David Rientjes Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

compaction: fix build error in CMA && !COMPACTION

2012-12-21T01:40:18Z

isolate_freepages_block() and isolate_migratepages_range() are used for CMA as well as compaction so it breaks build for CONFIG_CMA && !CONFIG_COMPACTION. This patch fixes it. [akpm@linux-foundation.org: add "do { } while (0)", per Mel] Signed-off-by: Minchan Kim Cc: Mel Gorman Cc: Marek Szyprowski Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge tag 'balancenuma-v11' of git://git.kernel.org/pub/scm/linux/kernel/git/mel/linux-balancenuma

2012-12-16T23:18:08Z

Pull Automatic NUMA Balancing bare-bones from Mel Gorman: "There are three implementations for NUMA balancing, this tree (balancenuma), numacore which has been developed in tip/master and autonuma which is in aa.git. In almost all respects balancenuma is the dumbest of the three because its main impact is on the VM side with no attempt to be smart about scheduling. In the interest of getting the ball rolling, it would be desirable to see this much merged for 3.8 with the view to building scheduler smarts on top and adapting the VM where required for 3.9. The most recent set of comparisons available from different people are mel: https://lkml.org/lkml/2012/12/9/108 mingo: https://lkml.org/lkml/2012/12/7/331 tglx: https://lkml.org/lkml/2012/12/10/437 srikar: https://lkml.org/lkml/2012/12/10/397 The results are a mixed bag. In my own tests, balancenuma does reasonably well. It's dumb as rocks and does not regress against mainline. On the other hand, Ingo's tests shows that balancenuma is incapable of converging for this workloads driven by perf which is bad but is potentially explained by the lack of scheduler smarts. Thomas' results show balancenuma improves on mainline but falls far short of numacore or autonuma. Srikar's results indicate we all suffer on a large machine with imbalanced node sizes. My own testing showed that recent numacore results have improved dramatically, particularly in the last week but not universally. We've butted heads heavily on system CPU usage and high levels of migration even when it shows that overall performance is better. There are also cases where it regresses. Of interest is that for specjbb in some configurations it will regress for lower numbers of warehouses and show gains for higher numbers which is not reported by the tool by default and sometimes missed in treports. Recently I reported for numacore that the JVM was crashing with NullPointerExceptions but currently it's unclear what the source of this problem is. Initially I thought it was in how numacore batch handles PTEs but I'm no longer think this is the case. It's possible numacore is just able to trigger it due to higher rates of migration. These reports were quite late in the cycle so I/we would like to start with this tree as it contains much of the code we can agree on and has not changed significantly over the last 2-3 weeks." * tag 'balancenuma-v11' of git://git.kernel.org/pub/scm/linux/kernel/git/mel/linux-balancenuma: (50 commits) mm/rmap, migration: Make rmap_walk_anon() and try_to_unmap_anon() more scalable mm/rmap: Convert the struct anon_vma::mutex to an rwsem mm: migrate: Account a transhuge page properly when rate limiting mm: numa: Account for failed allocations and isolations as migration failures mm: numa: Add THP migration for the NUMA working set scanning fault case build fix mm: numa: Add THP migration for the NUMA working set scanning fault case. mm: sched: numa: Delay PTE scanning until a task is scheduled on a new node mm: sched: numa: Control enabling and disabling of NUMA balancing if !SCHED_DEBUG mm: sched: numa: Control enabling and disabling of NUMA balancing mm: sched: Adapt the scanning rate if a NUMA hinting fault does not migrate mm: numa: Use a two-stage filter to restrict pages being migrated for unlikely task<->node relationships mm: numa: migrate: Set last_nid on newly allocated page mm: numa: split_huge_page: Transfer last_nid on tail page mm: numa: Introduce last_nid to the page frame sched: numa: Slowly increase the scanning period as NUMA faults are handled mm: numa: Rate limit setting of pte_numa if node is saturated mm: numa: Rate limit the amount of memory that is migrated between nodes mm: numa: Structures for Migrate On Fault per NUMA migration rate limiting mm: numa: Migrate pages handled during a pmd_numa hinting fault mm: numa: Migrate on reference policy ...

mm: compaction: Fix compiler warning

2012-12-13T01:38:32Z

compact_capture_page() is only used if compaction is enabled so it should be moved into the corresponding #ifdef. Signed-off-by: Thierry Reding Acked-by: Mel Gorman Cc: Rik van Riel Cc: Minchan Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds