user/sven/linux.git/include/linux/swap.h, branch v4.19.17

mm, swap, get_swap_pages: use entry_size instead of cluster in parameter

2018-08-22T17:52:44Z

As suggested by Matthew Wilcox, it is better to use "int entry_size" instead of "bool cluster" as parameter to specify whether to operate for huge or normal swap entries. Because this improve the flexibility to support other swap entry size. And Dave Hansen thinks that this improves code readability too. So in this patch, the "bool cluster" parameter of get_swap_pages() is replaced by "int entry_size". And nr_swap_entries() trick is used to reduce the binary size when !CONFIG_TRANSPARENT_HUGE_PAGE. text data bss dec hex filename base 24215 2028 340 26583 67d7 mm/swapfile.o head 24123 2004 340 26467 6763 mm/swapfile.o Link: http://lkml.kernel.org/r/20180720071845.17920-7-ying.huang@intel.com Signed-off-by: "Huang, Ying" Suggested-by: Matthew Wilcox Acked-by: Dave Hansen Cc: Daniel Jordan Cc: Michal Hocko Cc: Johannes Weiner Cc: Shaohua Li Cc: Hugh Dickins Cc: Minchan Kim Cc: Rik van Riel Cc: Dan Williams Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

memcontrol: schedule throttling if we are congested

2018-07-09T15:07:54Z

Memory allocations can induce swapping via kswapd or direct reclaim. If we are having IO done for us by kswapd and don't actually go into direct reclaim we may never get scheduled for throttling. So instead check to see if our cgroup is congested, and if so schedule the throttling. Before we return to user space the throttling stuff will only throttle if we actually required it. Signed-off-by: Tejun Heo Signed-off-by: Josef Bacik Acked-by: Johannes Weiner Acked-by: Andrew Morton Signed-off-by: Jens Axboe

Merge branch 'mm-rst' into docs-next

2018-04-16T20:25:08Z

Mike Rapoport says: These patches convert files in Documentation/vm to ReST format, add an initial index and link it to the top level documentation. There are no contents changes in the documentation, except few spelling fixes. The relatively large diffstat stems from the indentation and paragraph wrapping changes. I've tried to keep the formatting as consistent as possible, but I could miss some places that needed markup and add some markup where it was not necessary. [jc: significant conflicts in vm/hmm.rst]

docs/vm: rename documentation files to .rst

2018-04-16T20:18:15Z

Signed-off-by: Mike Rapoport Signed-off-by: Jonathan Corbet

mm: swap: unify cluster-based and vma-based swap readahead

2018-04-06T04:36:25Z

This patch makes do_swap_page() not need to be aware of two different swap readahead algorithms. Just unify cluster-based and vma-based readahead function call. Link: http://lkml.kernel.org/r/1509520520-32367-3-git-send-email-minchan@kernel.org Link: http://lkml.kernel.org/r/20180220085249.151400-3-minchan@kernel.org Signed-off-by: Minchan Kim Reviewed-by: Andrew Morton Cc: Hugh Dickins Cc: Huang Ying Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: swap: clean up swap readahead

2018-04-06T04:36:25Z

When I see recent change of swap readahead, I am very unhappy about current code structure which diverges two swap readahead algorithm in do_swap_page. This patch is to clean it up. Main motivation is that fault handler doesn't need to be aware of readahead algorithms but just should call swapin_readahead. As first step, this patch cleans up a little bit but not perfect (I just separate for review easier) so next patch will make the goal complete. [minchan@kernel.org: do not check readahead flag with THP anon] Link: http://lkml.kernel.org/r/874lm83zho.fsf@yhuang-dev.intel.com Link: http://lkml.kernel.org/r/20180227232611.169883-1-minchan@kernel.org Link: http://lkml.kernel.org/r/1509520520-32367-2-git-send-email-minchan@kernel.org Link: http://lkml.kernel.org/r/20180220085249.151400-2-minchan@kernel.org Signed-off-by: Minchan Kim Reviewed-by: Andrew Morton Cc: Hugh Dickins Cc: Huang Ying 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: remove unused pgdat_reclaimable_pages()

2018-02-01T01:18:37Z

Remove unused function pgdat_reclaimable_pages() and node_page_state_snapshot() which becomes unused as well. Link: http://lkml.kernel.org/r/20171122094416.26019-1-jack@suse.cz Signed-off-by: Jan Kara Acked-by: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: drop hotplug lock from lru_add_drain_all()

2018-02-01T01:18:36Z

Pulling cpu hotplug locks inside the mm core function like lru_add_drain_all just asks for problems and the recent lockdep splat [1] just proves this. While the usage in that particular case might be wrong we should avoid the locking as lru_add_drain_all() is used in many places. It seems that this is not all that hard to achieve actually. We have done the same thing for drain_all_pages which is analogous by commit a459eeb7b852 ("mm, page_alloc: do not depend on cpu hotplug locks inside the allocator"). All we have to care about is to handle - the work item might be executed on a different cpu in worker from unbound pool so it doesn't run on pinned on the cpu - we have to make sure that we do not race with page_alloc_cpu_dead calling lru_add_drain_cpu the first part is already handled because the worker calls lru_add_drain which disables preemption when calling lru_add_drain_cpu on the local cpu it is draining. The later is true because page_alloc_cpu_dead is called on the controlling CPU after the hotplugged CPU vanished completely. [1] http://lkml.kernel.org/r/089e0825eec8955c1f055c83d476@google.com [add a cpu hotplug locking interaction as per tglx] Link: http://lkml.kernel.org/r/20171116120535.23765-1-mhocko@kernel.org Signed-off-by: Michal Hocko Acked-by: Thomas Gleixner Cc: Tejun Heo Cc: Peter Zijlstra Cc: Johannes Weiner Cc: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: remove cold parameter for release_pages

2017-11-16T02:21:06Z

All callers of release_pages claim the pages being released are cache hot. As no one cares about the hotness of pages being released to the allocator, just ditch the parameter. No performance impact is expected as the overhead is marginal. The parameter is removed simply because it is a bit stupid to have a useless parameter copied everywhere. Link: http://lkml.kernel.org/r/20171018075952.10627-7-mgorman@techsingularity.net Signed-off-by: Mel Gorman Acked-by: Vlastimil Babka Cc: Andi Kleen Cc: Dave Chinner Cc: Dave Hansen Cc: Jan Kara Cc: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds