diff options
Diffstat (limited to 'mm/page-writeback.c')
| -rw-r--r-- | mm/page-writeback.c | 89 |
1 files changed, 53 insertions, 36 deletions
diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 0062d5c57d41..e5b38ffe9fca 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -32,7 +32,6 @@ #include <linux/sysctl.h> #include <linux/cpu.h> #include <linux/syscalls.h> -#include <linux/buffer_head.h> /* __set_page_dirty_buffers */ #include <linux/pagevec.h> #include <linux/timer.h> #include <linux/sched/rt.h> @@ -845,7 +844,7 @@ static long long pos_ratio_polynom(unsigned long setpoint, * ^ pos_ratio * | * | |<===== global dirty control scope ======>| - * 2.0 .............* + * 2.0 * * * * * * * * | .* * | . * * | . * @@ -1869,10 +1868,9 @@ DEFINE_PER_CPU(int, dirty_throttle_leaks) = 0; * which was newly dirtied. The function will periodically check the system's * dirty state and will initiate writeback if needed. * - * On really big machines, get_writeback_state is expensive, so try to avoid - * calling it too often (ratelimiting). But once we're over the dirty memory - * limit we decrease the ratelimiting by a lot, to prevent individual processes - * from overshooting the limit by (ratelimit_pages) each. + * Once we're over the dirty memory limit we decrease the ratelimiting + * by a lot, to prevent individual processes from overshooting the limit + * by (ratelimit_pages) each. */ void balance_dirty_pages_ratelimited(struct address_space *mapping) { @@ -1945,6 +1943,8 @@ bool wb_over_bg_thresh(struct bdi_writeback *wb) struct dirty_throttle_control * const gdtc = &gdtc_stor; struct dirty_throttle_control * const mdtc = mdtc_valid(&mdtc_stor) ? &mdtc_stor : NULL; + unsigned long reclaimable; + unsigned long thresh; /* * Similar to balance_dirty_pages() but ignores pages being written @@ -1957,8 +1957,13 @@ bool wb_over_bg_thresh(struct bdi_writeback *wb) if (gdtc->dirty > gdtc->bg_thresh) return true; - if (wb_stat(wb, WB_RECLAIMABLE) > - wb_calc_thresh(gdtc->wb, gdtc->bg_thresh)) + thresh = wb_calc_thresh(gdtc->wb, gdtc->bg_thresh); + if (thresh < 2 * wb_stat_error()) + reclaimable = wb_stat_sum(wb, WB_RECLAIMABLE); + else + reclaimable = wb_stat(wb, WB_RECLAIMABLE); + + if (reclaimable > thresh) return true; if (mdtc) { @@ -1972,8 +1977,13 @@ bool wb_over_bg_thresh(struct bdi_writeback *wb) if (mdtc->dirty > mdtc->bg_thresh) return true; - if (wb_stat(wb, WB_RECLAIMABLE) > - wb_calc_thresh(mdtc->wb, mdtc->bg_thresh)) + thresh = wb_calc_thresh(mdtc->wb, mdtc->bg_thresh); + if (thresh < 2 * wb_stat_error()) + reclaimable = wb_stat_sum(wb, WB_RECLAIMABLE); + else + reclaimable = wb_stat(wb, WB_RECLAIMABLE); + + if (reclaimable > thresh) return true; } @@ -2045,8 +2055,6 @@ void laptop_sync_completion(void) /* * If ratelimit_pages is too high then we can get into dirty-data overload * if a large number of processes all perform writes at the same time. - * If it is too low then SMP machines will call the (expensive) - * get_writeback_state too often. * * Here we set ratelimit_pages to a level which ensures that when all CPUs are * dirtying in parallel, we cannot go more than 3% (1/32) over the dirty memory @@ -2409,6 +2417,7 @@ int __set_page_dirty_no_writeback(struct page *page) return !TestSetPageDirty(page); return 0; } +EXPORT_SYMBOL(__set_page_dirty_no_writeback); /* * Helper function for set_page_dirty family. @@ -2417,7 +2426,8 @@ int __set_page_dirty_no_writeback(struct page *page) * * NOTE: This relies on being atomic wrt interrupts. */ -void account_page_dirtied(struct page *page, struct address_space *mapping) +static void account_page_dirtied(struct page *page, + struct address_space *mapping) { struct inode *inode = mapping->host; @@ -2436,7 +2446,7 @@ void account_page_dirtied(struct page *page, struct address_space *mapping) inc_wb_stat(wb, WB_DIRTIED); task_io_account_write(PAGE_SIZE); current->nr_dirtied++; - this_cpu_inc(bdp_ratelimits); + __this_cpu_inc(bdp_ratelimits); mem_cgroup_track_foreign_dirty(page, wb); } @@ -2459,6 +2469,30 @@ void account_page_cleaned(struct page *page, struct address_space *mapping, } /* + * Mark the page dirty, and set it dirty in the page cache, and mark the inode + * dirty. + * + * If warn is true, then emit a warning if the page is not uptodate and has + * not been truncated. + * + * The caller must hold lock_page_memcg(). + */ +void __set_page_dirty(struct page *page, struct address_space *mapping, + int warn) +{ + unsigned long flags; + + xa_lock_irqsave(&mapping->i_pages, flags); + if (page->mapping) { /* Race with truncate? */ + WARN_ON_ONCE(warn && !PageUptodate(page)); + account_page_dirtied(page, mapping); + __xa_set_mark(&mapping->i_pages, page_index(page), + PAGECACHE_TAG_DIRTY); + } + xa_unlock_irqrestore(&mapping->i_pages, flags); +} + +/* * For address_spaces which do not use buffers. Just tag the page as dirty in * the xarray. * @@ -2475,20 +2509,12 @@ int __set_page_dirty_nobuffers(struct page *page) lock_page_memcg(page); if (!TestSetPageDirty(page)) { struct address_space *mapping = page_mapping(page); - unsigned long flags; if (!mapping) { unlock_page_memcg(page); return 1; } - - xa_lock_irqsave(&mapping->i_pages, flags); - BUG_ON(page_mapping(page) != mapping); - WARN_ON_ONCE(!PagePrivate(page) && !PageUptodate(page)); - account_page_dirtied(page, mapping); - __xa_set_mark(&mapping->i_pages, page_index(page), - PAGECACHE_TAG_DIRTY); - xa_unlock_irqrestore(&mapping->i_pages, flags); + __set_page_dirty(page, mapping, !PagePrivate(page)); unlock_page_memcg(page); if (mapping->host) { @@ -2546,13 +2572,9 @@ EXPORT_SYMBOL(redirty_page_for_writepage); /* * Dirty a page. * - * For pages with a mapping this should be done under the page lock - * for the benefit of asynchronous memory errors who prefer a consistent - * dirty state. This rule can be broken in some special cases, - * but should be better not to. - * - * If the mapping doesn't provide a set_page_dirty a_op, then - * just fall through and assume that it wants buffer_heads. + * For pages with a mapping this should be done under the page lock for the + * benefit of asynchronous memory errors who prefer a consistent dirty state. + * This rule can be broken in some special cases, but should be better not to. */ int set_page_dirty(struct page *page) { @@ -2560,7 +2582,6 @@ int set_page_dirty(struct page *page) page = compound_head(page); if (likely(mapping)) { - int (*spd)(struct page *) = mapping->a_ops->set_page_dirty; /* * readahead/lru_deactivate_page could remain * PG_readahead/PG_reclaim due to race with end_page_writeback @@ -2573,11 +2594,7 @@ int set_page_dirty(struct page *page) */ if (PageReclaim(page)) ClearPageReclaim(page); -#ifdef CONFIG_BLOCK - if (!spd) - spd = __set_page_dirty_buffers; -#endif - return (*spd)(page); + return mapping->a_ops->set_page_dirty(page); } if (!PageDirty(page)) { if (!TestSetPageDirty(page)) |