kernel.git/mm/swap.c, branch linux-4.20.y

Merge branch 'xarray' of git://git.infradead.org/users/willy/linux-dax

2018-10-28T18:35:40Z

Pull XArray conversion from Matthew Wilcox: "The XArray provides an improved interface to the radix tree data structure, providing locking as part of the API, specifying GFP flags at allocation time, eliminating preloading, less re-walking the tree, more efficient iterations and not exposing RCU-protected pointers to its users. This patch set 1. Introduces the XArray implementation 2. Converts the pagecache to use it 3. Converts memremap to use it The page cache is the most complex and important user of the radix tree, so converting it was most important. Converting the memremap code removes the only other user of the multiorder code, which allows us to remove the radix tree code that supported it. I have 40+ followup patches to convert many other users of the radix tree over to the XArray, but I'd like to get this part in first. The other conversions haven't been in linux-next and aren't suitable for applying yet, but you can see them in the xarray-conv branch if you're interested" * 'xarray' of git://git.infradead.org/users/willy/linux-dax: (90 commits) radix tree: Remove multiorder support radix tree test: Convert multiorder tests to XArray radix tree tests: Convert item_delete_rcu to XArray radix tree tests: Convert item_kill_tree to XArray radix tree tests: Move item_insert_order radix tree test suite: Remove multiorder benchmarking radix tree test suite: Remove __item_insert memremap: Convert to XArray xarray: Add range store functionality xarray: Move multiorder_check to in-kernel tests xarray: Move multiorder_shrink to kernel tests xarray: Move multiorder account test in-kernel radix tree test suite: Convert iteration test to XArray radix tree test suite: Convert tag_tagged_items to XArray radix tree: Remove radix_tree_clear_tags radix tree: Remove radix_tree_maybe_preload_order radix tree: Remove split/join code radix tree: Remove radix_tree_update_node_t page cache: Finish XArray conversion dax: Convert page fault handlers to XArray ...

mm/swap.c: remove duplicated include

2018-10-26T23:26:33Z

Remove duplicated include linux/memremap.h Link: http://lkml.kernel.org/r/20180917131308.16420-1-yuehaibing@huawei.com Signed-off-by: YueHaibing Reviewed-by: Andrew Morton Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

pagevec: Use xa_mark_t

2018-10-21T14:46:39Z

Removes sparse warnings. Signed-off-by: Matthew Wilcox

xarray: Replace exceptional entries

2018-09-30T02:47:49Z

Introduce xarray value entries and tagged pointers to replace radix tree exceptional entries. This is a slight change in encoding to allow the use of an extra bit (we can now store BITS_PER_LONG - 1 bits in a value entry). It is also a change in emphasis; exceptional entries are intimidating and different. As the comment explains, you can choose to store values or pointers in the xarray and they are both first-class citizens. Signed-off-by: Matthew Wilcox Reviewed-by: Josef Bacik

mm: introduce MEMORY_DEVICE_FS_DAX and CONFIG_DEV_PAGEMAP_OPS

2018-05-22T13:59:39Z

In preparation for fixing dax-dma-vs-unmap issues, filesystems need to be able to rely on the fact that they will get wakeups on dev_pagemap page-idle events. Introduce MEMORY_DEVICE_FS_DAX and generic_dax_page_free() as common indicator / infrastructure for dax filesytems to require. With this change there are no users of the MEMORY_DEVICE_HOST designation, so remove it. The HMM sub-system extended dev_pagemap to arrange a callback when a dev_pagemap managed page is freed. Since a dev_pagemap page is free / idle when its reference count is 1 it requires an additional branch to check the page-type at put_page() time. Given put_page() is a hot-path we do not want to incur that check if HMM is not in use, so a static branch is used to avoid that overhead when not necessary. Now, the FS_DAX implementation wants to reuse this mechanism for receiving dev_pagemap ->page_free() callbacks. Rework the HMM-specific static-key into a generic mechanism that either HMM or FS_DAX code paths can enable. For ARCH=um builds, and any other arch that lacks ZONE_DEVICE support, care must be taken to compile out the DEV_PAGEMAP_OPS infrastructure. However, we still need to support FS_DAX in the FS_DAX_LIMITED case implemented by the s390/dcssblk driver. Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: Michal Hocko Reported-by: kbuild test robot Reported-by: Thomas Meyer Reported-by: Dave Jiang Cc: "Jérôme Glisse" Reviewed-by: Jan Kara Reviewed-by: Christoph Hellwig Signed-off-by: Dan Williams

mm/swap.c: remove @cold parameter description for release_pages()

2018-04-06T04:36:26Z

The 'cold' parameter was removed from release_pages function by commit c6f92f9fbe7d ("mm: remove cold parameter for release_pages"). Update the description to match the code. Link: http://lkml.kernel.org/r/1519585191-10180-3-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport Reviewed-by: Andrew Morton Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/swap.c: make functions and their kernel-doc agree (again)

2018-02-21T23:35:43Z

There was a conflict between the commit e02a9f048ef7 ("mm/swap.c: make functions and their kernel-doc agree") and the commit f144c390f905 ("mm: docs: fix parameter names mismatch") that both tried to fix mismatch betweeen pagevec_lookup_entries() parameter names and their description. Since nr_entries is a better name for the parameter, fix the description again. Link: http://lkml.kernel.org/r/1518116946-20947-1-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport Acked-by: Randy Dunlap Reviewed-by: Andrew Morton Cc: Matthew Wilcox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm, mlock, vmscan: no more skipping pagevecs

2018-02-21T23:35:42Z

When a thread mlocks an address space backed either by file pages which are currently not present in memory or swapped out anon pages (not in swapcache), a new page is allocated and added to the local pagevec (lru_add_pvec), I/O is triggered and the thread then sleeps on the page. On I/O completion, the thread can wake on a different CPU, the mlock syscall will then sets the PageMlocked() bit of the page but will not be able to put that page in unevictable LRU as the page is on the pagevec of a different CPU. Even on drain, that page will go to evictable LRU because the PageMlocked() bit is not checked on pagevec drain. The page will eventually go to right LRU on reclaim but the LRU stats will remain skewed for a long time. This patch puts all the pages, even unevictable, to the pagevecs and on the drain, the pages will be added on their LRUs correctly by checking their evictability. This resolves the mlocked pages on pagevec of other CPUs issue because when those pagevecs will be drained, the mlocked file pages will go to unevictable LRU. Also this makes the race with munlock easier to resolve because the pagevec drains happen in LRU lock. However there is still one place which makes a page evictable and does PageLRU check on that page without LRU lock and needs special attention. TestClearPageMlocked() and isolate_lru_page() in clear_page_mlock(). #0: __pagevec_lru_add_fn #1: clear_page_mlock SetPageLRU() if (!TestClearPageMlocked()) return smp_mb() // <--required // inside does PageLRU if (!PageMlocked()) if (isolate_lru_page()) move to evictable LRU putback_lru_page() else move to unevictable LRU In '#1', TestClearPageMlocked() provides full memory barrier semantics and thus the PageLRU check (inside isolate_lru_page) can not be reordered before it. In '#0', without explicit memory barrier, the PageMlocked() check can be reordered before SetPageLRU(). If that happens, '#0' can put a page in unevictable LRU and '#1' might have just cleared the Mlocked bit of that page but fails to isolate as PageLRU fails as '#0' still hasn't set PageLRU bit of that page. That page will be stranded on the unevictable LRU. There is one (good) side effect though. Without this patch, the pages allocated for System V shared memory segment are added to evictable LRUs even after shmctl(SHM_LOCK) on that segment. This patch will correctly put such pages to unevictable LRU. Link: http://lkml.kernel.org/r/20171121211241.18877-1-shakeelb@google.com Signed-off-by: Shakeel Butt Acked-by: Vlastimil Babka Cc: Jérôme Glisse Cc: Huang Ying Cc: Tim Chen Cc: Michal Hocko Cc: Greg Thelen Cc: Johannes Weiner Cc: Balbir Singh Cc: Minchan Kim Cc: Shaohua Li Cc: Jan Kara Cc: Nicholas Piggin Cc: Dan Williams Cc: Mel Gorman Cc: Hugh Dickins Cc: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: docs: fix parameter names mismatch

2018-02-07T02:32:48Z

There are several places where parameter descriptions do no match the actual code. Fix it. Link: http://lkml.kernel.org/r/1516700871-22279-3-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport Cc: Jonathan Corbet Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/swap.c: make functions and their kernel-doc agree

2018-02-01T01:18:40Z

Fix some basic kernel-doc notation in mm/swap.c: - for function lru_cache_add_anon(), make its kernel-doc function name match its function name and change colon to hyphen following the function name - for function pagevec_lookup_entries(), change the function parameter name from nr_pages to nr_entries since that is more descriptive of what the parameter actually is and then it matches the kernel-doc comments also Fix function kernel-doc to match the change in commit 67fd707f4681: - drop the kernel-doc notation for @nr_pages from pagevec_lookup_range() and correct the function description for that change Link: http://lkml.kernel.org/r/3b42ee3e-04a9-a6ca-6be4-f00752a114fe@infradead.org Fixes: 67fd707f4681 ("mm: remove nr_pages argument from pagevec_lookup_{,range}_tag()") Signed-off-by: Randy Dunlap Reviewed-by: Andrew Morton Cc: Jan Kara Cc: Matthew Wilcox Cc: Hugh Dickins Cc: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds