From: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx> Includes moving mapping_tagged() to fs.h as a static inline, and changing it to return bool. Signed-off-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx> --- include/linux/fs.h | 17 +++++++++------ mm/page-writeback.c | 62 +++++++++++++++++++---------------------------------- 2 files changed, 32 insertions(+), 47 deletions(-) diff --git a/include/linux/fs.h b/include/linux/fs.h index e4345c13e237..c58bc3c619bf 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -470,15 +470,18 @@ struct block_device { struct mutex bd_fsfreeze_mutex; } __randomize_layout; +/* XArray tags, for tagging dirty and writeback pages in the pagecache. */ +#define PAGECACHE_TAG_DIRTY XA_TAG_0 +#define PAGECACHE_TAG_WRITEBACK XA_TAG_1 +#define PAGECACHE_TAG_TOWRITE XA_TAG_2 + /* - * Radix-tree tags, for tagging dirty and writeback pages within the pagecache - * radix trees + * Returns true if any of the pages in the mapping are marked with the tag. */ -#define PAGECACHE_TAG_DIRTY 0 -#define PAGECACHE_TAG_WRITEBACK 1 -#define PAGECACHE_TAG_TOWRITE 2 - -int mapping_tagged(struct address_space *mapping, int tag); +static inline bool mapping_tagged(struct address_space *mapping, xa_tag_t tag) +{ + return xa_tagged(&mapping->pages, tag); +} static inline void i_mmap_lock_write(struct address_space *mapping) { diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 588ce729d199..0407436a8305 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2098,33 +2098,25 @@ void __init page_writeback_init(void) * dirty pages in the file (thus it is important for this function to be quick * so that it can tag pages faster than a dirtying process can create them). */ -/* - * We tag pages in batches of WRITEBACK_TAG_BATCH to reduce xa_lock latency. - */ void tag_pages_for_writeback(struct address_space *mapping, pgoff_t start, pgoff_t end) { -#define WRITEBACK_TAG_BATCH 4096 - unsigned long tagged = 0; - struct radix_tree_iter iter; - void **slot; + XA_STATE(xas, &mapping->pages, start); + unsigned int tagged = 0; + void *page; - xa_lock_irq(&mapping->pages); - radix_tree_for_each_tagged(slot, &mapping->pages, &iter, start, - PAGECACHE_TAG_DIRTY) { - if (iter.index > end) - break; - radix_tree_iter_tag_set(&mapping->pages, &iter, - PAGECACHE_TAG_TOWRITE); - tagged++; - if ((tagged % WRITEBACK_TAG_BATCH) != 0) + xas_lock_irq(&xas); + xas_for_each_tag(&xas, page, end, PAGECACHE_TAG_DIRTY) { + xas_set_tag(&xas, PAGECACHE_TAG_TOWRITE); + if (++tagged % XA_CHECK_SCHED) continue; - slot = radix_tree_iter_resume(slot, &iter); - xa_unlock_irq(&mapping->pages); + + xas_pause(&xas); + xas_unlock_irq(&xas); cond_resched(); - xa_lock_irq(&mapping->pages); + xas_lock_irq(&xas); } - xa_unlock_irq(&mapping->pages); + xas_unlock_irq(&xas); } EXPORT_SYMBOL(tag_pages_for_writeback); @@ -2164,7 +2156,7 @@ int write_cache_pages(struct address_space *mapping, pgoff_t done_index; int cycled; int range_whole = 0; - int tag; + xa_tag_t tag; pagevec_init(&pvec); if (wbc->range_cyclic) { @@ -2445,7 +2437,7 @@ void account_page_cleaned(struct page *page, struct address_space *mapping, /* * For address_spaces which do not use buffers. Just tag the page as dirty in - * its radix tree. + * the xarray. * * This is also used when a single buffer is being dirtied: we want to set the * page dirty in that case, but not all the buffers. This is a "bottom-up" @@ -2471,7 +2463,7 @@ int __set_page_dirty_nobuffers(struct page *page) BUG_ON(page_mapping(page) != mapping); WARN_ON_ONCE(!PagePrivate(page) && !PageUptodate(page)); account_page_dirtied(page, mapping); - radix_tree_tag_set(&mapping->pages, page_index(page), + __xa_set_tag(&mapping->pages, page_index(page), PAGECACHE_TAG_DIRTY); xa_unlock_irqrestore(&mapping->pages, flags); unlock_page_memcg(page); @@ -2634,13 +2626,13 @@ EXPORT_SYMBOL(__cancel_dirty_page); * Returns true if the page was previously dirty. * * This is for preparing to put the page under writeout. We leave the page - * tagged as dirty in the radix tree so that a concurrent write-for-sync + * tagged as dirty in the xarray so that a concurrent write-for-sync * can discover it via a PAGECACHE_TAG_DIRTY walk. The ->writepage * implementation will run either set_page_writeback() or set_page_dirty(), - * at which stage we bring the page's dirty flag and radix-tree dirty tag + * at which stage we bring the page's dirty flag and xarray dirty tag * back into sync. * - * This incoherency between the page's dirty flag and radix-tree tag is + * This incoherency between the page's dirty flag and xarray tag is * unfortunate, but it only exists while the page is locked. */ int clear_page_dirty_for_io(struct page *page) @@ -2721,7 +2713,7 @@ int test_clear_page_writeback(struct page *page) xa_lock_irqsave(&mapping->pages, flags); ret = TestClearPageWriteback(page); if (ret) { - radix_tree_tag_clear(&mapping->pages, page_index(page), + __xa_clear_tag(&mapping->pages, page_index(page), PAGECACHE_TAG_WRITEBACK); if (bdi_cap_account_writeback(bdi)) { struct bdi_writeback *wb = inode_to_wb(inode); @@ -2773,7 +2765,7 @@ int __test_set_page_writeback(struct page *page, bool keep_write) on_wblist = mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK); - radix_tree_tag_set(&mapping->pages, page_index(page), + __xa_set_tag(&mapping->pages, page_index(page), PAGECACHE_TAG_WRITEBACK); if (bdi_cap_account_writeback(bdi)) inc_wb_stat(inode_to_wb(inode), WB_WRITEBACK); @@ -2787,10 +2779,10 @@ int __test_set_page_writeback(struct page *page, bool keep_write) sb_mark_inode_writeback(mapping->host); } if (!PageDirty(page)) - radix_tree_tag_clear(&mapping->pages, page_index(page), + __xa_clear_tag(&mapping->pages, page_index(page), PAGECACHE_TAG_DIRTY); if (!keep_write) - radix_tree_tag_clear(&mapping->pages, page_index(page), + __xa_clear_tag(&mapping->pages, page_index(page), PAGECACHE_TAG_TOWRITE); xa_unlock_irqrestore(&mapping->pages, flags); } else { @@ -2806,16 +2798,6 @@ int __test_set_page_writeback(struct page *page, bool keep_write) } EXPORT_SYMBOL(__test_set_page_writeback); -/* - * Return true if any of the pages in the mapping are marked with the - * passed tag. - */ -int mapping_tagged(struct address_space *mapping, int tag) -{ - return radix_tree_tagged(&mapping->pages, tag); -} -EXPORT_SYMBOL(mapping_tagged); - /** * wait_for_stable_page() - wait for writeback to finish, if necessary. * @page: The page to wait on. -- 2.15.1 -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html