From 25ff8b15537dfa0e1a62d55cfcc48f3c8bd8a76c Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Mon, 3 May 2021 10:06:55 -0400 Subject: mm/writeback: Add folio_account_redirty() Account the number of pages in the folio that we're redirtying. Turn account_page_dirty() into a wrapper around it. Also turn the comment on folio_account_redirty() into kernel-doc and edit it slightly so it makes sense to its potential callers. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Christoph Hellwig Reviewed-by: David Howells Acked-by: Vlastimil Babka --- mm/page-writeback.c | 32 +++++++++++++++++++------------- 1 file changed, 19 insertions(+), 13 deletions(-) (limited to 'mm') diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 85c04445de97..7ef904363fb7 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -1084,7 +1084,7 @@ static void wb_update_write_bandwidth(struct bdi_writeback *wb, * write_bandwidth = --------------------------------------------------- * period * - * @written may have decreased due to account_page_redirty(). + * @written may have decreased due to folio_account_redirty(). * Avoid underflowing @bw calculation. */ bw = written - min(written, wb->written_stamp); @@ -2544,30 +2544,36 @@ bool filemap_dirty_folio(struct address_space *mapping, struct folio *folio) } EXPORT_SYMBOL(filemap_dirty_folio); -/* - * Call this whenever redirtying a page, to de-account the dirty counters - * (NR_DIRTIED, WB_DIRTIED, tsk->nr_dirtied), so that they match the written - * counters (NR_WRITTEN, WB_WRITTEN) in long term. The mismatches will lead to - * systematic errors in balanced_dirty_ratelimit and the dirty pages position - * control. +/** + * folio_account_redirty - Manually account for redirtying a page. + * @folio: The folio which is being redirtied. + * + * Most filesystems should call folio_redirty_for_writepage() instead + * of this fuction. If your filesystem is doing writeback outside the + * context of a writeback_control(), it can call this when redirtying + * a folio, to de-account the dirty counters (NR_DIRTIED, WB_DIRTIED, + * tsk->nr_dirtied), so that they match the written counters (NR_WRITTEN, + * WB_WRITTEN) in long term. The mismatches will lead to systematic errors + * in balanced_dirty_ratelimit and the dirty pages position control. */ -void account_page_redirty(struct page *page) +void folio_account_redirty(struct folio *folio) { - struct address_space *mapping = page->mapping; + struct address_space *mapping = folio->mapping; if (mapping && mapping_can_writeback(mapping)) { struct inode *inode = mapping->host; struct bdi_writeback *wb; struct wb_lock_cookie cookie = {}; + long nr = folio_nr_pages(folio); wb = unlocked_inode_to_wb_begin(inode, &cookie); - current->nr_dirtied--; - dec_node_page_state(page, NR_DIRTIED); - dec_wb_stat(wb, WB_DIRTIED); + current->nr_dirtied -= nr; + node_stat_mod_folio(folio, NR_DIRTIED, -nr); + wb_stat_mod(wb, WB_DIRTIED, -nr); unlocked_inode_to_wb_end(inode, &cookie); } } -EXPORT_SYMBOL(account_page_redirty); +EXPORT_SYMBOL(folio_account_redirty); /* * When a writepage implementation decides that it doesn't want to write this -- cgit v1.2.3