Re: [PATCHv2, RFC 00/30] Transparent huge page cache

From: Simon Jeons
Date: Mon Mar 18 2013 - 00:03:32 EST

Hi Kirill,
On 03/15/2013 01:50 AM, Kirill A. Shutemov wrote:
From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>

Here's the second version of the patchset.

The intend of the work is get code ready to enable transparent huge page
cache for the most simple fs -- ramfs.

We have read()/write()/mmap() functionality now. Still plenty work ahead.

One offline question.

Why set PG_mlocked to page_tail which be splited in function __split_huge_page_refcount?

Any feedback is welcome.

Changes since v1:
- mmap();
- fix add_to_page_cache_locked() and delete_from_page_cache();
- introduce mapping_can_have_hugepages();
- call split_huge_page() only for head page in filemap_fault();
- wait_split_huge_page(): serialize over i_mmap_mutex too;
- lru_add_page_tail: avoid PageUnevictable on active/inactive lru lists;
- fix off-by-one in zero_huge_user_segment();

- memcg accounting has not yet evaluated;
- collapse;
- migration (?);
- stats, knobs, etc.;
- tmpfs/shmem enabling;

Kirill A. Shutemov (30):
block: implement add_bdi_stat()
mm: implement zero_huge_user_segment and friends
mm: drop actor argument of do_generic_file_read()
radix-tree: implement preload for multiple contiguous elements
thp, mm: avoid PageUnevictable on active/inactive lru lists
thp, mm: basic defines for transparent huge page cache
thp, mm: introduce mapping_can_have_hugepages() predicate
thp, mm: rewrite add_to_page_cache_locked() to support huge pages
thp, mm: rewrite delete_from_page_cache() to support huge pages
thp, mm: locking tail page is a bug
thp, mm: handle tail pages in page_cache_get_speculative()
thp, mm: add event counters for huge page alloc on write to a file
thp, mm: implement grab_cache_huge_page_write_begin()
thp, mm: naive support of thp in generic read/write routines
thp, libfs: initial support of thp in
thp: handle file pages in split_huge_page()
thp: wait_split_huge_page(): serialize over i_mmap_mutex too
thp, mm: truncate support for transparent huge page cache
thp, mm: split huge page on mmap file page
ramfs: enable transparent huge page cache
x86-64, mm: proper alignment mappings with hugepages
mm: add huge_fault() callback to vm_operations_struct
thp: prepare zap_huge_pmd() to uncharge file pages
thp: move maybe_pmd_mkwrite() out of mk_huge_pmd()
thp, mm: basic huge_fault implementation for generic_file_vm_ops
thp: extract fallback path from do_huge_pmd_anonymous_page() to a
thp: initial implementation of do_huge_linear_fault()
thp: handle write-protect exception to file-backed huge pages
thp: call __vma_adjust_trans_huge() for file-backed VMA
thp: map file-backed huge pages on fault

arch/x86/kernel/sys_x86_64.c | 13 +-
fs/libfs.c | 50 ++++-
fs/ramfs/inode.c | 6 +-
include/linux/backing-dev.h | 10 +
include/linux/huge_mm.h | 36 +++-
include/linux/mm.h | 16 ++
include/linux/pagemap.h | 24 ++-
include/linux/radix-tree.h | 3 +
include/linux/vm_event_item.h | 2 +
lib/radix-tree.c | 32 ++-
mm/filemap.c | 283 +++++++++++++++++++++----
mm/huge_memory.c | 462 ++++++++++++++++++++++++++++++++++-------
mm/memory.c | 31 ++-
mm/swap.c | 3 +-
mm/truncate.c | 12 ++
mm/vmstat.c | 2 +
16 files changed, 842 insertions(+), 143 deletions(-)

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