From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> This patch set does not pass xfstests. Test at your own risk. It is based on the readahead patchset which I posted yesterday. The principal idea here is that a large part of the overhead in dealing with individual pages is that there's just so darned many of them. We would be better off dealing with fewer, larger pages, even if they don't get to be the size necessary for the CPU to use a larger TLB entry. The first five patches are more or less random cleanups which I came across while working on this patchset ... Andrew, if you want to just take those into your tree, it'd probably be a good thing. hpage_nr_pages() is adapted to handle arbitrary order pages. I also add thp_order() and thp_size() for legibility. Then the patches tear through the page cache fixing the places which assume pages are either PMD_SIZE or PAGE_SIZE. After that, I tackle the iomap buffered I/O path, removing the assumptions of PAGE_SIZE there. Finally, we get to actually allocating large pages in the readahead code. We gradually grow the page size that is allocated, so we don't just jump straight from order-0 to order-9 pages, but gradually get there through order-2, order-4, order-6, order-8 and order-9 (on x86; other architectures will have a different PMD_ORDER). In some testing, I've seen the code go as far as order-6. Right now it falls over on an earlier xfstest when it discovers a delayed allocation extent in an inode which is being removed at unmount. Matthew Wilcox (Oracle) (24): mm: Use vm_fault error code directly mm: Optimise find_subpage for !THP mm: Use VM_BUG_ON_PAGE in clear_page_dirty_for_io mm: Unexport find_get_entry mm: Fix documentation of FGP flags mm: Allow hpages to be arbitrary order mm: Introduce thp_size mm: Introduce thp_order fs: Add a filesystem flag for large pages fs: Introduce i_blocks_per_page fs: Make page_mkwrite_check_truncate thp-aware mm: Add file_offset_of_ helpers fs: Add zero_user_large iomap: Support arbitrarily many blocks per page iomap: Support large pages in iomap_adjust_read_range iomap: Support large pages in read paths iomap: Support large pages in write paths iomap: Inline data shouldn't see large pages xfs: Support large pages mm: Make prep_transhuge_page return its argument mm: Add __page_cache_alloc_order mm: Allow large pages to be added to the page cache mm: Allow large pages to be removed from the page cache mm: Add large page readahead William Kucharski (1): mm: Align THP mappings for non-DAX drivers/net/ethernet/ibm/ibmveth.c | 2 - drivers/nvdimm/btt.c | 4 +- drivers/nvdimm/pmem.c | 3 +- fs/iomap/buffered-io.c | 111 ++++++++++++++++------------- fs/jfs/jfs_metapage.c | 2 +- fs/xfs/xfs_aops.c | 4 +- fs/xfs/xfs_super.c | 2 +- include/linux/fs.h | 1 + include/linux/highmem.h | 22 ++++++ include/linux/huge_mm.h | 21 +++--- include/linux/mm.h | 2 + include/linux/pagemap.h | 78 ++++++++++++++++---- mm/filemap.c | 67 +++++++++++------ mm/huge_memory.c | 14 ++-- mm/internal.h | 2 +- mm/page-writeback.c | 2 +- mm/page_io.c | 2 +- mm/page_vma_mapped.c | 4 +- mm/readahead.c | 98 +++++++++++++++++++++++-- 19 files changed, 322 insertions(+), 119 deletions(-) -- 2.25.0
