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| author | Matthew Wilcox (Oracle) <willy@infradead.org> | 2020-10-13 16:51:24 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-10-13 18:38:29 -0700 |
| commit | e6e88712e43b7942df451508aafc2f083266f56b (patch) | |
| tree | ee72fadc853f21222d73acc482f343bac49df7f6 /mm/madvise.c | |
| parent | f5df8635c5a3c912919c91be64aa198554b0f9ed (diff) | |
| download | linux-e6e88712e43b7942df451508aafc2f083266f56b.tar.gz | |
mm: optimise madvise WILLNEED
Instead of calling find_get_entry() for every page index, use an XArray iterator to skip over NULL entries, and avoid calling get_page(), because we only want the swap entries. [willy@infradead.org: fix LTP soft lockups] Link: https://lkml.kernel.org/r/20200914165032.GS6583@casper.infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Huang Ying <ying.huang@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Matthew Auld <matthew.auld@intel.com> Cc: William Kucharski <william.kucharski@oracle.com> Cc: Qian Cai <cai@redhat.com> Link: https://lkml.kernel.org/r/20200910183318.20139-4-willy@infradead.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/madvise.c')
| -rw-r--r-- | mm/madvise.c | 21 |
1 files changed, 12 insertions, 9 deletions
diff --git a/mm/madvise.c b/mm/madvise.c index 0e0d61003fc6..9b065d412e5f 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -224,25 +224,28 @@ static void force_shm_swapin_readahead(struct vm_area_struct *vma, unsigned long start, unsigned long end, struct address_space *mapping) { - pgoff_t index; + XA_STATE(xas, &mapping->i_pages, linear_page_index(vma, start)); + pgoff_t end_index = end / PAGE_SIZE; struct page *page; - swp_entry_t swap; - for (; start < end; start += PAGE_SIZE) { - index = ((start - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; + rcu_read_lock(); + xas_for_each(&xas, page, end_index) { + swp_entry_t swap; - page = find_get_entry(mapping, index); - if (!xa_is_value(page)) { - if (page) - put_page(page); + if (!xa_is_value(page)) continue; - } + xas_pause(&xas); + rcu_read_unlock(); + swap = radix_to_swp_entry(page); page = read_swap_cache_async(swap, GFP_HIGHUSER_MOVABLE, NULL, 0, false); if (page) put_page(page); + + rcu_read_lock(); } + rcu_read_unlock(); lru_add_drain(); /* Push any new pages onto the LRU now */ } |