Ross Zwisler 642261ac99 dax: add struct iomap based DAX PMD support ... DAX PMDs have been disabled since Jan Kara introduced DAX radix tree based locking. This patch allows DAX PMDs to participate in the DAX radix tree based locking scheme so that they can be re-enabled using the new struct iomap based fault handlers. There are currently three types of DAX 4k entries: 4k zero pages, 4k DAX mappings that have an associated block allocation, and 4k DAX empty entries. The empty entries exist to provide locking for the duration of a given page fault. This patch adds three equivalent 2MiB DAX entries: Huge Zero Page (HZP) entries, PMD DAX entries that have associated block allocations, and 2 MiB DAX empty entries. Unlike the 4k case where we insert a struct page* into the radix tree for 4k zero pages, for HZP we insert a DAX exceptional entry with the new RADIX_DAX_HZP flag set. This is because we use a single 2 MiB zero page in every 2MiB hole mapping, and it doesn't make sense to have that same struct page* with multiple entries in multiple trees. This would cause contention on the single page lock for the one Huge Zero Page, and it would break the page->index and page->mapping associations that are assumed to be valid in many other places in the kernel. One difficult use case is when one thread is trying to use 4k entries in radix tree for a given offset, and another thread is using 2 MiB entries for that same offset. The current code handles this by making the 2 MiB user fall back to 4k entries for most cases. This was done because it is the simplest solution, and because the use of 2MiB pages is already opportunistic. If we were to try to upgrade from 4k pages to 2MiB pages for a given range, we run into the problem of how we lock out 4k page faults for the entire 2MiB range while we clean out the radix tree so we can insert the 2MiB entry. We can solve this problem if we need to, but I think that the cases where both 2MiB entries and 4K entries are being used for the same range will be rare enough and the gain small enough that it probably won't be worth the complexity. Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Dave Chinner <david@fromorbit.com>		2016-11-08 11:34:45 +11:00
..
kasan	kasan: remove the unnecessary WARN_ONCE from quarantine.c	2016-08-11 16:58:14 -07:00
backing-dev.c	block: fix bdi vs gendisk lifetime mismatch	2016-08-04 14:19:16 -06:00
balloon_compaction.c	mm: balloon: use general non-lru movable page feature	2016-07-26 16:19:19 -07:00
bootmem.c	mm: kmemleak: avoid using __va() on addresses that don't have a lowmem mapping	2016-10-11 15:06:33 -07:00
cleancache.c	cleancache: constify cleancache_ops structure	2016-01-27 09:09:57 -05:00
cma_debug.c	mm/cma_debug: correct size input to bitmap function	2015-07-17 16:39:54 -07:00
cma.c	mm: kmemleak: avoid using __va() on addresses that don't have a lowmem mapping	2016-10-11 15:06:33 -07:00
cma.h	mm: cma: mark cma_bitmap_maxno() inline in header	2015-08-14 15:56:32 -07:00
compaction.c	mm, compaction: restrict fragindex to costly orders	2016-10-07 18:46:29 -07:00
debug_page_ref.c	mm/page_ref: add tracepoint to track down page reference manipulation	2016-03-17 15:09:34 -07:00
debug.c	mm: clarify why we avoid page_mapcount() for slab pages in dump_page()	2016-10-07 18:46:29 -07:00
dmapool.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
early_ioremap.c	mm/early_ioremap: use offset_in_page macro	2015-11-05 19:34:48 -08:00
fadvise.c	mm/fadvise.c: do not discard partial pages with POSIX_FADV_DONTNEED	2016-06-09 14:23:11 -07:00
failslab.c	mm: fault-inject take over bootstrap kmem_cache check	2016-03-15 16:55:16 -07:00
filemap.c	dax: add struct iomap based DAX PMD support	2016-11-08 11:34:45 +11:00
frame_vector.c	mm/gup: Switch all callers of get_user_pages() to not pass tsk/mm	2016-02-16 10:11:12 +01:00
frontswap.c	mm, frontswap: convert frontswap_enabled to static key	2016-07-26 16:19:19 -07:00
gup.c	- ARM: GICv3 ITS emulation and various fixes. Removal of the old	2016-08-02 16:11:27 -04:00
highmem.c	mm/highmem: make nr_free_highpages() handles all highmem zones by itself	2016-05-19 19:12:14 -07:00
huge_memory.c	mm: vm_page_prot: update with WRITE_ONCE/READ_ONCE	2016-10-07 18:46:29 -07:00
hugetlb_cgroup.c	mm, hugetlb_cgroup: round limit_in_bytes down to hugepage size	2016-05-20 17:58:30 -07:00
hugetlb.c	mm: remove unnecessary condition in remove_inode_hugepages	2016-10-07 18:46:29 -07:00
hwpoison-inject.c	hwpoison: use page_cgroup_ino for filtering by memcg	2015-09-10 13:29:01 -07:00
init-mm.c
internal.h	mm, compaction: make full priority ignore pageblock suitability	2016-10-07 18:46:29 -07:00
interval_tree.c
Kconfig	mm: clarify COMPACTION Kconfig text	2016-08-26 17:39:35 -07:00
Kconfig.debug	PM / Hibernate: allow hibernation with PAGE_POISONING_ZERO	2016-09-13 02:35:27 +02:00
khugepaged.c	mm, thp: fix leaking mapped pte in __collapse_huge_page_swapin()	2016-09-19 15:36:16 -07:00
kmemcheck.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
kmemleak-test.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
kmemleak.c	mm: kmemleak: avoid using __va() on addresses that don't have a lowmem mapping	2016-10-11 15:06:33 -07:00
ksm.c	mm,ksm: add __GFP_HIGH to the allocation in alloc_stable_node()	2016-10-07 18:46:29 -07:00
list_lru.c	mm: memcontrol: move kmem accounting code to CONFIG_MEMCG	2016-01-20 17:09:18 -08:00
maccess.c	x86: remove more uaccess_32.h complexity	2016-05-22 17:21:27 -07:00
madvise.c	mm: make mmap_sem for write waits killable for mm syscalls	2016-05-23 17:04:14 -07:00
Makefile	Disable the __builtin_return_address() warning globally after all	2016-10-12 10:23:41 -07:00
memblock.c	mm: kmemleak: avoid using __va() on addresses that don't have a lowmem mapping	2016-10-11 15:06:33 -07:00
memcontrol.c	mm: memcontrol: consolidate cgroup socket tracking	2016-10-07 18:46:29 -07:00
memory_hotplug.c	mm/hugetlb: check for reserved hugepages during memory offline	2016-10-07 18:46:29 -07:00
memory-failure.c	mm: hwpoison: remove incorrect comments	2016-07-28 16:07:41 -07:00
memory.c	mm: fix cache mode tracking in vm_insert_mixed()	2016-10-07 18:46:28 -07:00
mempolicy.c	mm: use zonelist name instead of using hardcoded index	2016-10-07 18:46:28 -07:00
mempool.c	Revert "mm, mempool: only set __GFP_NOMEMALLOC if there are free elements"	2016-07-28 16:07:41 -07:00
memtest.c	memtest: remove unused header files	2015-09-08 15:35:28 -07:00
migrate.c	mm: vm_page_prot: update with WRITE_ONCE/READ_ONCE	2016-10-07 18:46:29 -07:00
mincore.c	mm, swap: use offset of swap entry as key of swap cache	2016-10-07 18:46:28 -07:00
mlock.c	mm: mlock: avoid increase mm->locked_vm on mlock() when already mlock2(,MLOCK_ONFAULT)	2016-10-07 18:46:28 -07:00
mm_init.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
mmap.c	mm: vma_merge: correct false positive from __vma_unlink->validate_mm_rb	2016-10-07 18:46:29 -07:00
mmu_context.c	mm/mmu_context, sched/core: Fix mmu_context.h assumption	2016-04-28 11:44:19 +02:00
mmu_notifier.c	fix Christoph's email addresses	2016-03-17 15:09:34 -07:00
mmzone.c	mm, page_alloc: inline the fast path of the zonelist iterator	2016-05-19 19:12:14 -07:00
mprotect.c	Merge branch 'mm-pkeys-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2016-10-10 11:01:51 -07:00
mremap.c	mm: thp: check pmd_trans_unstable() after split_huge_pmd()	2016-07-26 16:19:19 -07:00
msync.c	mm/msync: use offset_in_page macro	2015-11-05 19:34:48 -08:00
nobootmem.c	mm: kmemleak: avoid using __va() on addresses that don't have a lowmem mapping	2016-10-11 15:06:33 -07:00
nommu.c	mm: introduce fault_env	2016-07-26 16:19:19 -07:00
oom_kill.c	oom: print nodemask in the oom report	2016-10-07 18:46:29 -07:00
page_alloc.c	This adds a new gcc plugin named "latent_entropy". It is designed to	2016-10-15 10:03:15 -07:00
page_counter.c	mm: page_counter: let page_counter_try_charge() return bool	2015-11-05 19:34:48 -08:00
page_ext.c	mm/page_ext: support extra space allocation by page_ext user	2016-10-07 18:46:27 -07:00
page_idle.c	mm, vmscan: move lru_lock to the node	2016-07-28 16:07:41 -07:00
page_io.c	mm/page_io.c: replace some BUG_ON()s with VM_BUG_ON_PAGE()	2016-10-07 18:46:29 -07:00
page_isolation.c	mm/page_isolation: fix typo: "paes" -> "pages"	2016-10-07 18:46:29 -07:00
page_owner.c	mm/page_owner: don't define fields on struct page_ext by hard-coding	2016-10-07 18:46:27 -07:00
page_poison.c	mm: check the return value of lookup_page_ext for all call sites	2016-06-03 15:06:22 -07:00
page-writeback.c	mm: don't use radix tree writeback tags for pages in swap cache	2016-10-07 18:46:28 -07:00
pagewalk.c	thp: rename split_huge_page_pmd() to split_huge_pmd()	2016-01-15 17:56:32 -08:00
percpu-km.c	mm: percpu: use pr_fmt to prefix output	2016-03-17 15:09:34 -07:00
percpu-vm.c
percpu.c	mm/percpu.c: fix potential memory leakage for pcpu_embed_first_chunk()	2016-10-05 11:52:55 -04:00
pgtable-generic.c	mm/thp/migration: switch from flush_tlb_range to flush_pmd_tlb_range	2016-03-17 15:09:34 -07:00
process_vm_access.c	mm/gup: Introduce get_user_pages_remote()	2016-02-16 10:04:09 +01:00
quicklist.c	fix Christoph's email addresses	2016-03-17 15:09:34 -07:00
readahead.c	mm: silently skip readahead for DAX inodes	2016-08-26 17:39:35 -07:00
rmap.c	rmap: fix compound check logic in page_remove_file_rmap	2016-08-10 16:40:56 -07:00
shmem.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-10-10 20:16:43 -07:00
slab_common.c	mm: charge/uncharge kmemcg from generic page allocator paths	2016-07-26 16:19:19 -07:00
slab.c	slab: Convert to hotplug state machine	2016-09-06 18:30:20 +02:00
slab.h	mm, kasan: switch SLUB to stackdepot, enable memory quarantine for SLUB	2016-07-28 16:07:41 -07:00
slob.c	mm: slab: free kmem_cache_node after destroy sysfs file	2016-02-18 16:23:24 -08:00
slub.c	slub: Convert to hotplug state machine	2016-09-06 18:30:20 +02:00
sparse-vmemmap.c	treewide: replace obsolete _refok by __ref	2016-08-02 17:31:41 -04:00
sparse.c	treewide: replace obsolete _refok by __ref	2016-08-02 17:31:41 -04:00
swap_cgroup.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
swap_state.c	mm, swap: use offset of swap entry as key of swap cache	2016-10-07 18:46:28 -07:00
swap.c	thp: reduce usage of huge zero page's atomic counter	2016-10-07 18:46:28 -07:00
swapfile.c	mm, swap: use offset of swap entry as key of swap cache	2016-10-07 18:46:28 -07:00
truncate.c	truncate: handle file thp	2016-07-26 16:19:19 -07:00
usercopy.c	mm: usercopy: Check for module addresses	2016-09-20 16:07:39 -07:00
userfaultfd.c	mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros	2016-04-04 10:41:08 -07:00
util.c	mm: move most file-based accounting to the node	2016-07-28 16:07:41 -07:00
vmacache.c	mm: unrig VMA cache hit ratio	2016-10-07 18:46:27 -07:00
vmalloc.c	mm: consolidate warn_alloc_failed users	2016-10-07 18:46:29 -07:00
vmpressure.c	mm/vmpressure.c: fix subtree pressure detection	2016-02-03 08:28:43 -08:00
vmscan.c	mm: use zonelist name instead of using hardcoded index	2016-10-07 18:46:28 -07:00
vmstat.c	seq/proc: modify seq_put_decimal_[u]ll to take a const char *, not char	2016-10-07 18:46:30 -07:00
workingset.c	mm: workingset: fix crash in shadow node shrinker caused by replace_page_cache_page()	2016-09-30 15:26:52 -07:00
z3fold.c	mm/z3fold.c: avoid modifying HEADLESS page and minor cleanup	2016-06-03 16:02:55 -07:00
zbud.c	mm/zbud.c: use list_last_entry() instead of list_tail_entry()	2016-01-15 11:40:52 -08:00
zpool.c	mm: zsmalloc: constify struct zs_pool name	2015-11-06 17:50:42 -08:00
zsmalloc.c	zsmalloc: Delete an unnecessary check before the function call "iput"	2016-07-28 16:07:41 -07:00
zswap.c	mm/zswap: use workqueue to destroy pool	2016-05-20 17:58:30 -07:00