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* mm: page_alloc: convert hot/cold parameter and immediate callers to boolMel Gorman2014-06-043-4/+4
| | | | | | | | | | | | | | | | | | | | | cold is a bool, make it one. Make the likely case the "if" part of the block instead of the else as according to the optimisation manual this is preferred. Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jan Kara <jack@suse.cz> Cc: Michal Hocko <mhocko@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: page_alloc: use unsigned int for order in more placesMel Gorman2014-06-041-4/+4
| | | | | | | | | | | | | | | | | | | | | | X86 prefers the use of unsigned types for iterators and there is a tendency to mix whether a signed or unsigned type if used for page order. This converts a number of sites in mm/page_alloc.c to use unsigned int for order where possible. Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jan Kara <jack@suse.cz> Cc: Michal Hocko <mhocko@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: page_alloc: reduce number of times page_to_pfn is calledMel Gorman2014-06-042-22/+20
| | | | | | | | | | | | | | | | | | | In the free path we calculate page_to_pfn multiple times. Reduce that. Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Jan Kara <jack@suse.cz> Cc: Michal Hocko <mhocko@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: page_alloc: use word-based accesses for get/set pageblock bitmapsMel Gorman2014-06-042-7/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The test_bit operations in get/set pageblock flags are expensive. This patch reads the bitmap on a word basis and use shifts and masks to isolate the bits of interest. Similarly masks are used to set a local copy of the bitmap and then use cmpxchg to update the bitmap if there have been no other changes made in parallel. In a test running dd onto tmpfs the overhead of the pageblock-related functions went from 1.27% in profiles to 0.5%. In addition to the performance benefits, this patch closes races that are possible between: a) get_ and set_pageblock_migratetype(), where get_pageblock_migratetype() reads part of the bits before and other part of the bits after set_pageblock_migratetype() has updated them. b) set_pageblock_migratetype() and set_pageblock_skip(), where the non-atomic read-modify-update set bit operation in set_pageblock_skip() will cause lost updates to some bits changed in the set_pageblock_migratetype(). Joonsoo Kim first reported the case a) via code inspection. Vlastimil Babka's testing with a debug patch showed that either a) or b) occurs roughly once per mmtests' stress-highalloc benchmark (although not necessarily in the same pageblock). Furthermore during development of unrelated compaction patches, it was observed that frequent calls to {start,undo}_isolate_page_range() the race occurs several thousands of times and has resulted in NULL pointer dereferences in move_freepages() and free_one_page() in places where free_list[migratetype] is manipulated by e.g. list_move(). Further debugging confirmed that migratetype had invalid value of 6, causing out of bounds access to the free_list array. That confirmed that the race exist, although it may be extremely rare, and currently only fatal where page isolation is performed due to memory hot remove. Races on pageblocks being updated by set_pageblock_migratetype(), where both old and new migratetype are lower MIGRATE_RESERVE, currently cannot result in an invalid value being observed, although theoretically they may still lead to unexpected creation or destruction of MIGRATE_RESERVE pageblocks. Furthermore, things could get suddenly worse when memory isolation is used more, or when new migratetypes are added. After this patch, the race has no longer been observed in testing. Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reported-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Reported-and-tested-by: Vlastimil Babka <vbabka@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jan Kara <jack@suse.cz> Cc: Michal Hocko <mhocko@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: page_alloc: use jump labels to avoid checking number_of_cpusetsMel Gorman2014-06-041-3/+26
| | | | | | | | | | | | | | | | | | | | | If cpusets are not in use then we still check a global variable on every page allocation. Use jump labels to avoid the overhead. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jan Kara <jack@suse.cz> Cc: Michal Hocko <mhocko@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* include/linux/jump_label.h: expose the reference countMel Gorman2014-06-041-7/+13
| | | | | | | | | | | | | | | | | | | | | This patch exposes the jump_label reference count in preparation for the next patch. cpusets cares about both the jump_label being enabled and how many users of the cpusets there currently are. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jan Kara <jack@suse.cz> Cc: Michal Hocko <mhocko@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: cleanup kmem cache creation/destruction functions namingVladimir Davydov2014-06-042-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | Current names are rather inconsistent. Let's try to improve them. Brief change log: ** old name ** ** new name ** kmem_cache_create_memcg memcg_create_kmem_cache memcg_kmem_create_cache memcg_regsiter_cache memcg_kmem_destroy_cache memcg_unregister_cache kmem_cache_destroy_memcg_children memcg_cleanup_cache_params mem_cgroup_destroy_all_caches memcg_unregister_all_caches create_work memcg_register_cache_work memcg_create_cache_work_func memcg_register_cache_func memcg_create_cache_enqueue memcg_schedule_register_cache Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* swap: change swap_list_head to plist, add swap_avail_headDan Streetman2014-06-042-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Originally get_swap_page() started iterating through the singly-linked list of swap_info_structs using swap_list.next or highest_priority_index, which both were intended to point to the highest priority active swap target that was not full. The first patch in this series changed the singly-linked list to a doubly-linked list, and removed the logic to start at the highest priority non-full entry; it starts scanning at the highest priority entry each time, even if the entry is full. Replace the manually ordered swap_list_head with a plist, swap_active_head. Add a new plist, swap_avail_head. The original swap_active_head plist contains all active swap_info_structs, as before, while the new swap_avail_head plist contains only swap_info_structs that are active and available, i.e. not full. Add a new spinlock, swap_avail_lock, to protect the swap_avail_head list. Mel Gorman suggested using plists since they internally handle ordering the list entries based on priority, which is exactly what swap was doing manually. All the ordering code is now removed, and swap_info_struct entries and simply added to their corresponding plist and automatically ordered correctly. Using a new plist for available swap_info_structs simplifies and optimizes get_swap_page(), which no longer has to iterate over full swap_info_structs. Using a new spinlock for swap_avail_head plist allows each swap_info_struct to add or remove themselves from the plist when they become full or not-full; previously they could not do so because the swap_info_struct->lock is held when they change from full<->not-full, and the swap_lock protecting the main swap_active_head must be ordered before any swap_info_struct->lock. Signed-off-by: Dan Streetman <ddstreet@ieee.org> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Shaohua Li <shli@fusionio.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Hugh Dickins <hughd@google.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com> Cc: Weijie Yang <weijieut@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Bob Liu <bob.liu@oracle.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib/plist: add plist_requeueDan Streetman2014-06-041-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add plist_requeue(), which moves the specified plist_node after all other same-priority plist_nodes in the list. This is essentially an optimized plist_del() followed by plist_add(). This is needed by swap, which (with the next patch in this set) uses a plist of available swap devices. When a swap device (either a swap partition or swap file) are added to the system with swapon(), the device is added to a plist, ordered by the swap device's priority. When swap needs to allocate a page from one of the swap devices, it takes the page from the first swap device on the plist, which is the highest priority swap device. The swap device is left in the plist until all its pages are used, and then removed from the plist when it becomes full. However, as described in man 2 swapon, swap must allocate pages from swap devices with the same priority in round-robin order; to do this, on each swap page allocation, swap uses a page from the first swap device in the plist, and then calls plist_requeue() to move that swap device entry to after any other same-priority swap devices. The next swap page allocation will again use a page from the first swap device in the plist and requeue it, and so on, resulting in round-robin usage of equal-priority swap devices. Also add plist_test_requeue() test function, for use by plist_test() to test plist_requeue() function. Signed-off-by: Dan Streetman <ddstreet@ieee.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Shaohua Li <shli@fusionio.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com> Cc: Weijie Yang <weijieut@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Bob Liu <bob.liu@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib/plist: add helper functionsDan Streetman2014-06-041-0/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add PLIST_HEAD() to plist.h, equivalent to LIST_HEAD() from list.h, to define and initialize a struct plist_head. Add plist_for_each_continue() and plist_for_each_entry_continue(), equivalent to list_for_each_continue() and list_for_each_entry_continue(), to iterate over a plist continuing after the current position. Add plist_prev() and plist_next(), equivalent to (struct list_head*)->prev and ->next, implemented by list_prev_entry() and list_next_entry(), to access the prev/next struct plist_node entry. These are needed because unlike struct list_head, direct access of the prev/next struct plist_node isn't possible; the list must be navigated via the contained struct list_head. e.g. instead of accessing the prev by list_prev_entry(node, node_list) it can be accessed by plist_prev(node). Signed-off-by: Dan Streetman <ddstreet@ieee.org> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Shaohua Li <shli@fusionio.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com> Cc: Weijie Yang <weijieut@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Bob Liu <bob.liu@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* swap: change swap_info singly-linked list to list_headDan Streetman2014-06-042-7/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The logic controlling the singly-linked list of swap_info_struct entries for all active, i.e. swapon'ed, swap targets is rather complex, because: - it stores the entries in priority order - there is a pointer to the highest priority entry - there is a pointer to the highest priority not-full entry - there is a highest_priority_index variable set outside the swap_lock - swap entries of equal priority should be used equally this complexity leads to bugs such as: https://lkml.org/lkml/2014/2/13/181 where different priority swap targets are incorrectly used equally. That bug probably could be solved with the existing singly-linked lists, but I think it would only add more complexity to the already difficult to understand get_swap_page() swap_list iteration logic. The first patch changes from a singly-linked list to a doubly-linked list using list_heads; the highest_priority_index and related code are removed and get_swap_page() starts each iteration at the highest priority swap_info entry, even if it's full. While this does introduce unnecessary list iteration (i.e. Schlemiel the painter's algorithm) in the case where one or more of the highest priority entries are full, the iteration and manipulation code is much simpler and behaves correctly re: the above bug; and the fourth patch removes the unnecessary iteration. The second patch adds some minor plist helper functions; nothing new really, just functions to match existing regular list functions. These are used by the next two patches. The third patch adds plist_requeue(), which is used by get_swap_page() in the next patch - it performs the requeueing of same-priority entries (which moves the entry to the end of its priority in the plist), so that all equal-priority swap_info_structs get used equally. The fourth patch converts the main list into a plist, and adds a new plist that contains only swap_info entries that are both active and not full. As Mel suggested using plists allows removing all the ordering code from swap - plists handle ordering automatically. The list naming is also clarified now that there are two lists, with the original list changed from swap_list_head to swap_active_head and the new list named swap_avail_head. A new spinlock is also added for the new list, so swap_info entries can be added or removed from the new list immediately as they become full or not full. This patch (of 4): Replace the singly-linked list tracking active, i.e. swapon'ed, swap_info_struct entries with a doubly-linked list using struct list_heads. Simplify the logic iterating and manipulating the list of entries, especially get_swap_page(), by using standard list_head functions, and removing the highest priority iteration logic. The change fixes the bug: https://lkml.org/lkml/2014/2/13/181 in which different priority swap entries after the highest priority entry are incorrectly used equally in pairs. The swap behavior is now as advertised, i.e. different priority swap entries are used in order, and equal priority swap targets are used concurrently. Signed-off-by: Dan Streetman <ddstreet@ieee.org> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Shaohua Li <shli@fusionio.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com> Cc: Weijie Yang <weijieut@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Bob Liu <bob.liu@oracle.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, compaction: embed migration mode in compact_controlDavid Rientjes2014-06-041-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | We're going to want to manipulate the migration mode for compaction in the page allocator, and currently compact_control's sync field is only a bool. Currently, we only do MIGRATE_ASYNC or MIGRATE_SYNC_LIGHT compaction depending on the value of this bool. Convert the bool to enum migrate_mode and pass the migration mode in directly. Later, we'll want to avoid MIGRATE_SYNC_LIGHT for thp allocations in the pagefault patch to avoid unnecessary latency. This also alters compaction triggered from sysfs, either for the entire system or for a node, to force MIGRATE_SYNC. [akpm@linux-foundation.org: fix build] [iamjoonsoo.kim@lge.com: use MIGRATE_SYNC in alloc_contig_range()] Signed-off-by: David Rientjes <rientjes@google.com> Suggested-by: Mel Gorman <mgorman@suse.de> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Greg Thelen <gthelen@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, compaction: add per-zone migration pfn cache for async compactionDavid Rientjes2014-06-041-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | Each zone has a cached migration scanner pfn for memory compaction so that subsequent calls to memory compaction can start where the previous call left off. Currently, the compaction migration scanner only updates the per-zone cached pfn when pageblocks were not skipped for async compaction. This creates a dependency on calling sync compaction to avoid having subsequent calls to async compaction from scanning an enormous amount of non-MOVABLE pageblocks each time it is called. On large machines, this could be potentially very expensive. This patch adds a per-zone cached migration scanner pfn only for async compaction. It is updated everytime a pageblock has been scanned in its entirety and when no pages from it were successfully isolated. The cached migration scanner pfn for sync compaction is updated only when called for sync compaction. Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Greg Thelen <gthelen@google.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, migration: add destination page freeing callbackDavid Rientjes2014-06-041-4/+7
| | | | | | | | | | | | | | | | | | | | | | | | Memory migration uses a callback defined by the caller to determine how to allocate destination pages. When migration fails for a source page, however, it frees the destination page back to the system. This patch adds a memory migration callback defined by the caller to determine how to free destination pages. If a caller, such as memory compaction, builds its own freelist for migration targets, this can reuse already freed memory instead of scanning additional memory. If the caller provides a function to handle freeing of destination pages, it is called when page migration fails. If the caller passes NULL then freeing back to the system will be handled as usual. This patch introduces no functional change. Signed-off-by: David Rientjes <rientjes@google.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Greg Thelen <gthelen@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: get rid of memcg_create_cache_nameVladimir Davydov2014-06-042-3/+2
| | | | | | | | | | | | | Instead of calling back to memcontrol.c from kmem_cache_create_memcg in order to just create the name of a per memcg cache, let's allocate it in place. We only need to pass the memcg name to kmem_cache_create_memcg for that - everything else can be done in slab_common.c. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: update comment for DEFAULT_MAX_MAP_COUNTKirill A. Shutemov2014-06-041-0/+4
| | | | | | | | | With ELF extended numbering 16-bit bound is not hard limit any more. [akpm@linux-foundation.org: fix typo] Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/rmap.c: make page_referenced_one() and try_to_unmap_one() staticKirill A. Shutemov2014-06-041-4/+0
| | | | | | | | | | | KSM was converted to use rmap_walk() and now nobody uses these functions outside mm/rmap.c. Let's covert them back to static. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* include/linux/bootmem.h: cleanup the comment for BOOTMEM_ flagsWang Sheng-Hui2014-06-041-3/+3
| | | | | | | | Use BOOTMEM_DEFAULT instead of 0 in the comment. Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: introdule compound_head_by_tail()Jianyu Zhan2014-06-041-12/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, in put_compound_page(), we have ====== if (likely(!PageTail(page))) { <------ (1) if (put_page_testzero(page)) { /* ¦* By the time all refcounts have been released ¦* split_huge_page cannot run anymore from under us. ¦*/ if (PageHead(page)) __put_compound_page(page); else __put_single_page(page); } return; } /* __split_huge_page_refcount can run under us */ page_head = compound_head(page); <------------ (2) ====== if at (1) , we fail the check, this means page is *likely* a tail page. Then at (2), as compoud_head(page) is inlined, it is : ====== static inline struct page *compound_head(struct page *page) { if (unlikely(PageTail(page))) { <----------- (3) struct page *head = page->first_page; smp_rmb(); if (likely(PageTail(page))) return head; } return page; } ====== here, the (3) unlikely in the case is a negative hint, because it is *likely* a tail page. So the check (3) in this case is not good, so I introduce a helper for this case. So this patch introduces compound_head_by_tail() which deals with a possible tail page(though it could be spilt by a racy thread), and make compound_head() a wrapper on it. This patch has no functional change, and it reduces the object size slightly: text data bss dec hex filename 11003 1328 16 12347 303b mm/swap.o.orig 10971 1328 16 12315 301b mm/swap.o.patched I've ran "perf top -e branch-miss" to observe branch-miss in this case. As Michael points out, it's a slow path, so only very few times this case happens. But I grep'ed the code base, and found there still are some other call sites could be benifited from this helper. And given that it only bloating up the source by only 5 lines, but with a reduced object size. I still believe this helper deserves to exsit. Signed-off-by: Jianyu Zhan <nasa4836@gmail.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Rik van Riel <riel@redhat.com> Cc: Jiang Liu <liuj97@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: constify nmask argument to set_mempolicy()Rasmus Villemoes2014-06-041-1/+1
| | | | | | | | | | The nmask argument to set_mempolicy() is const according to the user-space header numaif.h, and since the kernel does indeed not modify it, it might as well be declared const in the kernel. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: constify nmask argument to mbind()Rasmus Villemoes2014-06-041-1/+1
| | | | | | | | | | | The nmask argument to mbind() is const according to the userspace header numaif.h, and since the kernel does indeed not modify it, it might as well be declared const in the kernel. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs/block_dev.c: add bdev_read_page() and bdev_write_page()Matthew Wilcox2014-06-041-0/+4
| | | | | | | | | | | | | | | A block device driver may choose to provide a rw_page operation. These will be called when the filesystem is attempting to do page sized I/O to page cache pages (ie not for direct I/O). This does preclude I/Os that are larger than page size, so this may only be a performance gain for some devices. Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Tested-by: Dheeraj Reddy <dheeraj.reddy@intel.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs/mpage.c: factor page_endio() out of mpage_end_io()Matthew Wilcox2014-06-041-0/+2
| | | | | | | | | | | | | | page_endio() takes care of updating all the appropriate page flags once I/O has finished to a page. Switch to using mapping_set_error() instead of setting AS_EIO directly; this will handle thin-provisioned devices correctly. Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Dheeraj Reddy <dheeraj.reddy@intel.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs/buffer.c: remove block_write_full_page_endio()Matthew Wilcox2014-06-041-2/+0
| | | | | | | | | | | | | | | The last in-tree caller of block_write_full_page_endio() was removed in January 2013. It's time to remove the EXPORT_SYMBOL, which leaves block_write_full_page() as the only caller of block_write_full_page_endio(), so inline block_write_full_page_endio() into block_write_full_page(). Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Dheeraj Reddy <dheeraj.reddy@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg, slab: simplify synchronization schemeVladimir Davydov2014-06-042-14/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | At present, we have the following mutexes protecting data related to per memcg kmem caches: - slab_mutex. This one is held during the whole kmem cache creation and destruction paths. We also take it when updating per root cache memcg_caches arrays (see memcg_update_all_caches). As a result, taking it guarantees there will be no changes to any kmem cache (including per memcg). Why do we need something else then? The point is it is private to slab implementation and has some internal dependencies with other mutexes (get_online_cpus). So we just don't want to rely upon it and prefer to introduce additional mutexes instead. - activate_kmem_mutex. Initially it was added to synchronize initializing kmem limit (memcg_activate_kmem). However, since we can grow per root cache memcg_caches arrays only on kmem limit initialization (see memcg_update_all_caches), we also employ it to protect against memcg_caches arrays relocation (e.g. see __kmem_cache_destroy_memcg_children). - We have a convention not to take slab_mutex in memcontrol.c, but we want to walk over per memcg memcg_slab_caches lists there (e.g. for destroying all memcg caches on offline). So we have per memcg slab_caches_mutex's protecting those lists. The mutexes are taken in the following order: activate_kmem_mutex -> slab_mutex -> memcg::slab_caches_mutex Such a syncrhonization scheme has a number of flaws, for instance: - We can't call kmem_cache_{destroy,shrink} while walking over a memcg::memcg_slab_caches list due to locking order. As a result, in mem_cgroup_destroy_all_caches we schedule the memcg_cache_params::destroy work shrinking and destroying the cache. - We don't have a mutex to synchronize per memcg caches destruction between memcg offline (mem_cgroup_destroy_all_caches) and root cache destruction (__kmem_cache_destroy_memcg_children). Currently we just don't bother about it. This patch simplifies it by substituting per memcg slab_caches_mutex's with the global memcg_slab_mutex. It will be held whenever a new per memcg cache is created or destroyed, so it protects per root cache memcg_caches arrays and per memcg memcg_slab_caches lists. The locking order is following: activate_kmem_mutex -> memcg_slab_mutex -> slab_mutex This allows us to call kmem_cache_{create,shrink,destroy} under the memcg_slab_mutex. As a result, we don't need memcg_cache_params::destroy work any more - we can simply destroy caches while iterating over a per memcg slab caches list. Also using the global mutex simplifies synchronization between concurrent per memcg caches creation/destruction, e.g. mem_cgroup_destroy_all_caches vs __kmem_cache_destroy_memcg_children. The downside of this is that we substitute per-memcg slab_caches_mutex's with a hummer-like global mutex, but since we already take either the slab_mutex or the cgroup_mutex along with a memcg::slab_caches_mutex, it shouldn't hurt concurrency a lot. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Glauber Costa <glommer@gmail.com> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg, slab: merge memcg_{bind,release}_pages to memcg_{un}charge_slabVladimir Davydov2014-06-041-2/+2
| | | | | | | | | | | | | | | | Currently we have two pairs of kmemcg-related functions that are called on slab alloc/free. The first is memcg_{bind,release}_pages that count the total number of pages allocated on a kmem cache. The second is memcg_{un}charge_slab that {un}charge slab pages to kmemcg resource counter. Let's just merge them to keep the code clean. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Glauber Costa <glommer@gmail.com> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg, slab: do not schedule cache destruction when last page goes awayVladimir Davydov2014-06-042-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patchset is a part of preparations for kmemcg re-parenting. It targets at simplifying kmemcg work-flows and synchronization. First, it removes async per memcg cache destruction (see patches 1, 2). Now caches are only destroyed on memcg offline. That means the caches that are not empty on memcg offline will be leaked. However, they are already leaked, because memcg_cache_params::nr_pages normally never drops to 0 so the destruction work is never scheduled except kmem_cache_shrink is called explicitly. In the future I'm planning reaping such dead caches on vmpressure or periodically. Second, it substitutes per memcg slab_caches_mutex's with the global memcg_slab_mutex, which should be taken during the whole per memcg cache creation/destruction path before the slab_mutex (see patch 3). This greatly simplifies synchronization among various per memcg cache creation/destruction paths. I'm still not quite sure about the end picture, in particular I don't know whether we should reap dead memcgs' kmem caches periodically or try to merge them with their parents (see https://lkml.org/lkml/2014/4/20/38 for more details), but whichever way we choose, this set looks like a reasonable change to me, because it greatly simplifies kmemcg work-flows and eases further development. This patch (of 3): After a memcg is offlined, we mark its kmem caches that cannot be deleted right now due to pending objects as dead by setting the memcg_cache_params::dead flag, so that memcg_release_pages will schedule cache destruction (memcg_cache_params::destroy) as soon as the last slab of the cache is freed (memcg_cache_params::nr_pages drops to zero). I guess the idea was to destroy the caches as soon as possible, i.e. immediately after freeing the last object. However, it just doesn't work that way, because kmem caches always preserve some pages for the sake of performance, so that nr_pages never gets to zero unless the cache is shrunk explicitly using kmem_cache_shrink. Of course, we could account the total number of objects on the cache or check if all the slabs allocated for the cache are empty on kmem_cache_free and schedule destruction if so, but that would be too costly. Thus we have a piece of code that works only when we explicitly call kmem_cache_shrink, but complicates the whole picture a lot. Moreover, it's racy in fact. For instance, kmem_cache_shrink may free the last slab and thus schedule cache destruction before it finishes checking that the cache is empty, which can lead to use-after-free. So I propose to remove this async cache destruction from memcg_release_pages, and check if the cache is empty explicitly after calling kmem_cache_shrink instead. This will simplify things a lot w/o introducing any functional changes. And regarding dead memcg caches (i.e. those that are left hanging around after memcg offline for they have objects), I suppose we should reap them either periodically or on vmpressure as Glauber suggested initially. I'm going to implement this later. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Glauber Costa <glommer@gmail.com> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: kill CONFIG_MM_OWNEROleg Nesterov2014-06-042-3/+3
| | | | | | | | | | | | CONFIG_MM_OWNER makes no sense. It is not user-selectable, it is only selected by CONFIG_MEMCG automatically. So we can kill this option in init/Kconfig and do s/CONFIG_MM_OWNER/CONFIG_MEMCG/ globally. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/swap.c: clean up *lru_cache_add* functionsJianyu Zhan2014-06-041-17/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | In mm/swap.c, __lru_cache_add() is exported, but actually there are no users outside this file. This patch unexports __lru_cache_add(), and makes it static. It also exports lru_cache_add_file(), as it is use by cifs and fuse, which can loaded as modules. Signed-off-by: Jianyu Zhan <nasa4836@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Shaohua Li <shli@kernel.org> Cc: Bob Liu <bob.liu@oracle.com> Cc: Seth Jennings <sjenning@linux.vnet.ibm.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Rafael Aquini <aquini@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: Christoph Hellwig <hch@lst.de> Reviewed-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mem-hotplug: implement get/put_online_memsVladimir Davydov2014-06-042-14/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kmem_cache_{create,destroy,shrink} need to get a stable value of cpu/node online mask, because they init/destroy/access per-cpu/node kmem_cache parts, which can be allocated or destroyed on cpu/mem hotplug. To protect against cpu hotplug, these functions use {get,put}_online_cpus. However, they do nothing to synchronize with memory hotplug - taking the slab_mutex does not eliminate the possibility of race as described in patch 2. What we need there is something like get_online_cpus, but for memory. We already have lock_memory_hotplug, which serves for the purpose, but it's a bit of a hammer right now, because it's backed by a mutex. As a result, it imposes some limitations to locking order, which are not desirable, and can't be used just like get_online_cpus. That's why in patch 1 I substitute it with get/put_online_mems, which work exactly like get/put_online_cpus except they block not cpu, but memory hotplug. [ v1 can be found at https://lkml.org/lkml/2014/4/6/68. I NAK'ed it by myself, because it used an rw semaphore for get/put_online_mems, making them dead lock prune. ] This patch (of 2): {un}lock_memory_hotplug, which is used to synchronize against memory hotplug, is currently backed by a mutex, which makes it a bit of a hammer - threads that only want to get a stable value of online nodes mask won't be able to proceed concurrently. Also, it imposes some strong locking ordering rules on it, which narrows down the set of its usage scenarios. This patch introduces get/put_online_mems, which are the same as get/put_online_cpus, but for memory hotplug, i.e. executing a code inside a get/put_online_mems section will guarantee a stable value of online nodes, present pages, etc. lock_memory_hotplug()/unlock_memory_hotplug() are removed altogether. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Cc: Toshi Kani <toshi.kani@hp.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Jiang Liu <liuj97@gmail.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: page_alloc: do not cache reclaim distancesMel Gorman2014-06-041-1/+0
| | | | | | | | | | | | | | | | pgdat->reclaim_nodes tracks if a remote node is allowed to be reclaimed by zone_reclaim due to its distance. As it is expected that zone_reclaim_mode will be rarely enabled it is unreasonable for all machines to take a penalty. Fortunately, the zone_reclaim_mode() path is already slow and it is the path that takes the hit. Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Acked-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: disable zone_reclaim_mode by defaultMel Gorman2014-06-041-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When it was introduced, zone_reclaim_mode made sense as NUMA distances punished and workloads were generally partitioned to fit into a NUMA node. NUMA machines are now common but few of the workloads are NUMA-aware and it's routine to see major performance degradation due to zone_reclaim_mode being enabled but relatively few can identify the problem. Those that require zone_reclaim_mode are likely to be able to detect when it needs to be enabled and tune appropriately so lets have a sensible default for the bulk of users. This patch (of 2): zone_reclaim_mode causes processes to prefer reclaiming memory from local node instead of spilling over to other nodes. This made sense initially when NUMA machines were almost exclusively HPC and the workload was partitioned into nodes. The NUMA penalties were sufficiently high to justify reclaiming the memory. On current machines and workloads it is often the case that zone_reclaim_mode destroys performance but not all users know how to detect this. Favour the common case and disable it by default. Users that are sophisticated enough to know they need zone_reclaim_mode will detect it. Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Acked-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hugetlb: add hstate_is_gigantic()Luiz Capitulino2014-06-041-0/+5
| | | | | | | | | | | | | | | | Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Reviewed-by: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Reviewed-by: Davidlohr Bueso <davidlohr@hp.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: pass VM_BUG_ON() reason to dump_page()Dave Hansen2014-06-041-2/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | I recently added a patch to let folks pass a "reason" string dump_page() which gets dumped out along with the page's data. This essentially saves the bug-reader a trip in to the source to figure out why we BUG_ON()'d. The new VM_BUG_ON_PAGE() passes in NULL for "reason". It seems like we might as well pass the BUG_ON() condition if we have it. This will bloat kernels a bit with ~160 new strings, but this is all under a debugging option anyway. page:ffffea0008560280 count:1 mapcount:0 mapping:(null) index:0x0 page flags: 0xbfffc0000000001(locked) page dumped because: VM_BUG_ON_PAGE(PageLocked(page)) ------------[ cut here ]------------ kernel BUG at /home/davehans/linux.git/mm/filemap.c:464! invalid opcode: 0000 [#1] SMP CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.14.0+ #251 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 ... [akpm@linux-foundation.org: include stringify.h] Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Davidlohr Bueso <davidlohr@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* include/linux/mmdebug.h: add VM_WARN_ON() and VM_WARN_ON_ONCE()Andrew Morton2014-06-041-0/+4
| | | | | | | | WARN_ON() and WARN_ON_ONCE(), dependent on CONFIG_DEBUG_VM Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cma: add placement specifier for "cma=" kernel parameterAkinobu Mita2014-06-041-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, "cma=" kernel parameter is used to specify the size of CMA, but we can't specify where it is located. We want to locate CMA below 4GB for devices only supporting 32-bit addressing on 64-bit systems without iommu. This enables to specify the placement of CMA by extending "cma=" kernel parameter. Examples: 1. locate 64MB CMA below 4GB by "cma=64M@0-4G" 2. locate 64MB CMA exact at 512MB by "cma=64M@512M" Note that the DMA contiguous memory allocator on x86 assumes that page_address() works for the pages to allocate. So this change requires to limit end address of contiguous memory area upto max_pfn_mapped to prevent from locating it on highmem area by the argument of dma_contiguous_reserve(). Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Don Dutile <ddutile@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memblock: introduce memblock_alloc_range()Akinobu Mita2014-06-041-0/+2
| | | | | | | | | | | | | | | | | | | This introduces memblock_alloc_range() which allocates memblock from the specified range of physical address. I would like to use this function to specify the location of CMA. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Don Dutile <ddutile@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86: enable DMA CMA with swiotlbAkinobu Mita2014-06-041-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The DMA Contiguous Memory Allocator support on x86 is disabled when swiotlb config option is enabled. So DMA CMA is always disabled on x86_64 because swiotlb is always enabled. This attempts to support for DMA CMA with enabling swiotlb config option. The contiguous memory allocator on x86 is integrated in the function dma_generic_alloc_coherent() which is .alloc callback in nommu_dma_ops for dma_alloc_coherent(). x86_swiotlb_alloc_coherent() which is .alloc callback in swiotlb_dma_ops tries to allocate with dma_generic_alloc_coherent() firstly and then swiotlb_alloc_coherent() is called as a fallback. The main part of supporting DMA CMA with swiotlb is that changing x86_swiotlb_free_coherent() which is .free callback in swiotlb_dma_ops for dma_free_coherent() so that it can distinguish memory allocated by dma_generic_alloc_coherent() from one allocated by swiotlb_alloc_coherent() and release it with dma_generic_free_coherent() which can handle contiguous memory. This change requires making is_swiotlb_buffer() global function. This also needs to change .free callback in the dma_map_ops for amd_gart and sta2x11, because these dma_ops are also using dma_generic_alloc_coherent(). Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Don Dutile <ddutile@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm,vmacache: add debug dataDavidlohr Bueso2014-06-042-0/+10
| | | | | | | | | | | | | Introduce a CONFIG_DEBUG_VM_VMACACHE option to enable counting the cache hit rate -- exported in /proc/vmstat. Any updates to the caching scheme needs this kind of data, thus it can save some work re-implementing the counting all the time. Signed-off-by: Davidlohr Bueso <davidlohr@hp.com> Cc: Aswin Chandramouleeswaran <aswin@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: get rid of __GFP_KMEMCGVladimir Davydov2014-06-044-17/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently to allocate a page that should be charged to kmemcg (e.g. threadinfo), we pass __GFP_KMEMCG flag to the page allocator. The page allocated is then to be freed by free_memcg_kmem_pages. Apart from looking asymmetrical, this also requires intrusion to the general allocation path. So let's introduce separate functions that will alloc/free pages charged to kmemcg. The new functions are called alloc_kmem_pages and free_kmem_pages. They should be used when the caller actually would like to use kmalloc, but has to fall back to the page allocator for the allocation is large. They only differ from alloc_pages and free_pages in that besides allocating or freeing pages they also charge them to the kmem resource counter of the current memory cgroup. [sfr@canb.auug.org.au: export kmalloc_order() to modules] Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Acked-by: Greg Thelen <gthelen@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Glauber Costa <glommer@gmail.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sl[au]b: charge slabs to kmemcg explicitlyVladimir Davydov2014-06-041-11/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | We have only a few places where we actually want to charge kmem so instead of intruding into the general page allocation path with __GFP_KMEMCG it's better to explictly charge kmem there. All kmem charges will be easier to follow that way. This is a step towards removing __GFP_KMEMCG. It removes __GFP_KMEMCG from memcg caches' allocflags. Instead it makes slab allocation path call memcg_charge_kmem directly getting memcg to charge from the cache's memcg params. This also eliminates any possibility of misaccounting an allocation going from one memcg's cache to another memcg, because now we always charge slabs against the memcg the cache belongs to. That's why this patch removes the big comment to memcg_kmem_get_cache. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Acked-by: Greg Thelen <gthelen@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Glauber Costa <glommer@gmail.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86: define _PAGE_NUMA by reusing software bits on the PMD and PTE levelsMel Gorman2014-06-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | _PAGE_NUMA is currently an alias of _PROT_PROTNONE to trap NUMA hinting faults on x86. Care is taken such that _PAGE_NUMA is used only in situations where the VMA flags distinguish between NUMA hinting faults and prot_none faults. This decision was x86-specific and conceptually it is difficult requiring special casing to distinguish between PROTNONE and NUMA ptes based on context. Fundamentally, we only need the _PAGE_NUMA bit to tell the difference between an entry that is really unmapped and a page that is protected for NUMA hinting faults as if the PTE is not present then a fault will be trapped. Swap PTEs on x86-64 use the bits after _PAGE_GLOBAL for the offset. This patch shrinks the maximum possible swap size and uses the bit to uniquely distinguish between NUMA hinting ptes and swap ptes. Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Anvin <hpa@zytor.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Steven Noonan <steven@uplinklabs.net> Cc: Rik van Riel <riel@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Cyrill Gorcunov <gorcunov@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs/libfs.c: add generic data flush to fsyncFabian Frederick2014-06-042-0/+10
| | | | | | | | | | | | | | | | | | | | | | Description by Jan Kara: "A lot of older filesystems don't properly flush volatile disk caches on fsync(2) which can lead to loss of fsynced data after power failure. This patch makes generic_file_fsync() issue proper cache flush to fix the problem. Sysadmin can use /sys/devices/.../cache_type to tell the system it should not send the cache flush." [akpm@linux-foundation.org: nuke ifdef] [akpm@linux-foundation.org: fix warning] Signed-off-by: Fabian Frederick <fabf@skynet.be> Suggested-by: Jan Kara <jack@suse.cz> Suggested-by: Christoph Hellwig <hch@infradead.org> Cc: Jan Kara <jack@suse.cz> Cc: Christoph Hellwig <hch@infradead.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hugetlb: restrict hugepage_migration_support() to x86_64Naoya Horiguchi2014-06-042-8/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently hugepage migration is available for all archs which support pmd-level hugepage, but testing is done only for x86_64 and there're bugs for other archs. So to avoid breaking such archs, this patch limits the availability strictly to x86_64 until developers of other archs get interested in enabling this feature. Simply disabling hugepage migration on non-x86_64 archs is not enough to fix the reported problem where sys_move_pages() hits the BUG_ON() in follow_page(FOLL_GET), so let's fix this by checking if hugepage migration is supported in vma_migratable(). Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reported-by: Michael Ellerman <mpe@ellerman.id.au> Tested-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Hugh Dickins <hughd@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Miller <davem@davemloft.net> Cc: <stable@vger.kernel.org> [3.12+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'devicetree-for-3.16' of ↵Linus Torvalds2014-06-0410-89/+91
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux into next Pull DeviceTree updates from Rob Herring: - Another round of clean-up of FDT related code in architecture code. This removes knowledge of internal FDT details from most architectures except powerpc. - Conversion of kernel's custom FDT parsing code to use libfdt. - DT based initialization for generic serial earlycon. The introduction of generic serial earlycon support went in through the tty tree. - Improve the platform device naming for DT probed devices to ensure unique naming and use parent names instead of a global index. - Fix a race condition in of_update_property. - Unify the various linker section OF match tables and fix several function prototype errors. - Update platform_get_irq_byname to work in deferred probe cases. - 2 binding doc updates * tag 'devicetree-for-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (58 commits) of: handle NULL node in next_child iterators of/irq: provide more wrappers for !CONFIG_OF devicetree: bindings: Document micrel vendor prefix dt: bindings: dwc2: fix required value for the phy-names property of_pci_irq: kill useless variable in of_irq_parse_pci() of/irq: do irq resolution in platform_get_irq_byname() of: Add a testcase for of_find_node_by_path() of: Make of_find_node_by_path() handle /aliases of: Create unlocked version of for_each_child_of_node() lib: add glibc style strchrnul() variant of: Handle memory@0 node on PPC32 only pci/of: Remove dead code of: fix race between search and remove in of_update_property() of: Use NULL for pointers of: Stop naming platform_device using dcr address of: Ensure unique names without sacrificing determinism tty/serial: pl011: add DT based earlycon support of/fdt: add FDT serial scanning for earlycon of/fdt: add FDT address translation support serial: earlycon: add DT support ...
| * of/irq: provide more wrappers for !CONFIG_OFArnd Bergmann2014-06-041-3/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The pci-rcar driver is enabled for compile tests, and this has now shown that the driver cannot build without CONFIG_OF, following the inclusion of f8f2fe7355fb "PCI: rcar: Use new OF interrupt mapping when possible": drivers/built-in.o: In function `rcar_pci_map_irq': :(.text+0x1cc7c): undefined reference to `of_irq_parse_and_map_pci' pci/host/pcie-rcar.c: In function 'pci_dma_range_parser_init': pci/host/pcie-rcar.c:875:2: error: implicit declaration of function 'of_n_addr_cells' [-Werror=implicit-function-declaration] As pointed out by Ben Dooks and Geert Uytterhoeven, this is actually supposed to build fine, which we can achieve if we make the declaration of of_irq_parse_and_map_pci conditional on CONFIG_OF and provide an empty inline function otherwise, as we do for a lot of other of interfaces. This lets us build the rcar_pci driver again without CONFIG_OF for build testing. All platforms using this driver select OF, so this doesn't change anything for the users. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: devicetree@vger.kernel.org Cc: Rob Herring <robh+dt@kernel.org> Cc: Grant Likely <grant.likely@linaro.org> Cc: Lucas Stach <l.stach@pengutronix.de> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Magnus Damm <damm@opensource.se> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ben Dooks <ben.dooks@codethink.co.uk> Cc: linux-pci@vger.kernel.org Cc: linux-sh@vger.kernel.org [robh: drop wrappers for of_n_addr_cells and of_n_size_cells which are low-level functions that should not be used for !OF] Signed-off-by: Rob Herring <robh@kernel.org>
| * Merge branch 'earlycon-dt' into for-nextRob Herring2014-05-287-36/+57
| |\
| | * of/fdt: add FDT address translation supportRob Herring2014-05-201-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Copy u-boot's FDT address translation code from common/fdt_support. This code was originally based on the kernel's unflattened DT address parsing code. This commit can be reverted once relicensing of this code to GPLv2/BSD is done and it is added to libfdt. Signed-off-by: Rob Herring <robh@kernel.org> Acked-by: Grant Likely <grant.likely@linaro.org>
| | * serial: earlycon: add DT supportRob Herring2014-05-201-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds the infrastructure to generic earlycon for earlycon setup using DT. The actual setup is not enabled until a following commit to add the FDT parsing. Signed-off-by: Rob Herring <robh@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Arnd Bergmann <arnd@arndb.de> Acked-by: Grant Likely <grant.likely@linaro.org>
| | * of: consolidate linker section OF match table declarationsRob Herring2014-05-204-33/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We now have several OF match tables using linker sections that are nearly the same definition. The only variation is the callback function prototype. Create a common define for creating linker section OF match table entries which each table declaration can use. Acked-by: Grant Likely <grant.likely@linaro.org> Signed-off-by: Rob Herring <robh@kernel.org>