diff options
Diffstat (limited to 'mm/page-writeback.c')
| -rw-r--r-- | mm/page-writeback.c | 123 |
1 files changed, 51 insertions, 72 deletions
diff --git a/mm/page-writeback.c b/mm/page-writeback.c index f5236f804aa..e0c943014eb 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -156,24 +156,6 @@ static unsigned long writeout_period_time = 0; #define VM_COMPLETIONS_PERIOD_LEN (3*HZ) /* - * Work out the current dirty-memory clamping and background writeout - * thresholds. - * - * The main aim here is to lower them aggressively if there is a lot of mapped - * memory around. To avoid stressing page reclaim with lots of unreclaimable - * pages. It is better to clamp down on writers than to start swapping, and - * performing lots of scanning. - * - * We only allow 1/2 of the currently-unmapped memory to be dirtied. - * - * We don't permit the clamping level to fall below 5% - that is getting rather - * excessive. - * - * We make sure that the background writeout level is below the adjusted - * clamping level. - */ - -/* * In a memory zone, there is a certain amount of pages we consider * available for the page cache, which is essentially the number of * free and reclaimable pages, minus some zone reserves to protect @@ -191,6 +173,26 @@ static unsigned long writeout_period_time = 0; * global dirtyable memory first. */ +/** + * zone_dirtyable_memory - number of dirtyable pages in a zone + * @zone: the zone + * + * Returns the zone's number of pages potentially available for dirty + * page cache. This is the base value for the per-zone dirty limits. + */ +static unsigned long zone_dirtyable_memory(struct zone *zone) +{ + unsigned long nr_pages; + + nr_pages = zone_page_state(zone, NR_FREE_PAGES); + nr_pages -= min(nr_pages, zone->dirty_balance_reserve); + + nr_pages += zone_page_state(zone, NR_INACTIVE_FILE); + nr_pages += zone_page_state(zone, NR_ACTIVE_FILE); + + return nr_pages; +} + static unsigned long highmem_dirtyable_memory(unsigned long total) { #ifdef CONFIG_HIGHMEM @@ -198,11 +200,9 @@ static unsigned long highmem_dirtyable_memory(unsigned long total) unsigned long x = 0; for_each_node_state(node, N_HIGH_MEMORY) { - struct zone *z = - &NODE_DATA(node)->node_zones[ZONE_HIGHMEM]; + struct zone *z = &NODE_DATA(node)->node_zones[ZONE_HIGHMEM]; - x += zone_page_state(z, NR_FREE_PAGES) + - zone_reclaimable_pages(z) - z->dirty_balance_reserve; + x += zone_dirtyable_memory(z); } /* * Unreclaimable memory (kernel memory or anonymous memory @@ -238,9 +238,12 @@ static unsigned long global_dirtyable_memory(void) { unsigned long x; - x = global_page_state(NR_FREE_PAGES) + global_reclaimable_pages(); + x = global_page_state(NR_FREE_PAGES); x -= min(x, dirty_balance_reserve); + x += global_page_state(NR_INACTIVE_FILE); + x += global_page_state(NR_ACTIVE_FILE); + if (!vm_highmem_is_dirtyable) x -= highmem_dirtyable_memory(x); @@ -289,32 +292,6 @@ void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty) } /** - * zone_dirtyable_memory - number of dirtyable pages in a zone - * @zone: the zone - * - * Returns the zone's number of pages potentially available for dirty - * page cache. This is the base value for the per-zone dirty limits. - */ -static unsigned long zone_dirtyable_memory(struct zone *zone) -{ - /* - * The effective global number of dirtyable pages may exclude - * highmem as a big-picture measure to keep the ratio between - * dirty memory and lowmem reasonable. - * - * But this function is purely about the individual zone and a - * highmem zone can hold its share of dirty pages, so we don't - * care about vm_highmem_is_dirtyable here. - */ - unsigned long nr_pages = zone_page_state(zone, NR_FREE_PAGES) + - zone_reclaimable_pages(zone); - - /* don't allow this to underflow */ - nr_pages -= min(nr_pages, zone->dirty_balance_reserve); - return nr_pages; -} - -/** * zone_dirty_limit - maximum number of dirty pages allowed in a zone * @zone: the zone * @@ -598,14 +575,14 @@ unsigned long bdi_dirty_limit(struct backing_dev_info *bdi, unsigned long dirty) * (5) the closer to setpoint, the smaller |df/dx| (and the reverse) * => fast response on large errors; small oscillation near setpoint */ -static inline long long pos_ratio_polynom(unsigned long setpoint, +static long long pos_ratio_polynom(unsigned long setpoint, unsigned long dirty, unsigned long limit) { long long pos_ratio; long x; - x = div_s64(((s64)setpoint - (s64)dirty) << RATELIMIT_CALC_SHIFT, + x = div64_s64(((s64)setpoint - (s64)dirty) << RATELIMIT_CALC_SHIFT, limit - setpoint + 1); pos_ratio = x; pos_ratio = pos_ratio * x >> RATELIMIT_CALC_SHIFT; @@ -847,7 +824,7 @@ static unsigned long bdi_position_ratio(struct backing_dev_info *bdi, x_intercept = bdi_setpoint + span; if (bdi_dirty < x_intercept - span / 4) { - pos_ratio = div_u64(pos_ratio * (x_intercept - bdi_dirty), + pos_ratio = div64_u64(pos_ratio * (x_intercept - bdi_dirty), x_intercept - bdi_setpoint + 1); } else pos_ratio /= 4; @@ -1210,11 +1187,11 @@ static unsigned long dirty_poll_interval(unsigned long dirty, return 1; } -static long bdi_max_pause(struct backing_dev_info *bdi, - unsigned long bdi_dirty) +static unsigned long bdi_max_pause(struct backing_dev_info *bdi, + unsigned long bdi_dirty) { - long bw = bdi->avg_write_bandwidth; - long t; + unsigned long bw = bdi->avg_write_bandwidth; + unsigned long t; /* * Limit pause time for small memory systems. If sleeping for too long @@ -1226,7 +1203,7 @@ static long bdi_max_pause(struct backing_dev_info *bdi, t = bdi_dirty / (1 + bw / roundup_pow_of_two(1 + HZ / 8)); t++; - return min_t(long, t, MAX_PAUSE); + return min_t(unsigned long, t, MAX_PAUSE); } static long bdi_min_pause(struct backing_dev_info *bdi, @@ -1329,9 +1306,9 @@ static inline void bdi_dirty_limits(struct backing_dev_info *bdi, *bdi_thresh = bdi_dirty_limit(bdi, dirty_thresh); if (bdi_bg_thresh) - *bdi_bg_thresh = div_u64((u64)*bdi_thresh * - background_thresh, - dirty_thresh); + *bdi_bg_thresh = dirty_thresh ? div_u64((u64)*bdi_thresh * + background_thresh, + dirty_thresh) : 0; /* * In order to avoid the stacked BDI deadlock we need @@ -1567,9 +1544,9 @@ pause: bdi_start_background_writeback(bdi); } -void set_page_dirty_balance(struct page *page, int page_mkwrite) +void set_page_dirty_balance(struct page *page) { - if (set_page_dirty(page) || page_mkwrite) { + if (set_page_dirty(page)) { struct address_space *mapping = page_mapping(page); if (mapping) @@ -1628,7 +1605,7 @@ void balance_dirty_pages_ratelimited(struct address_space *mapping) * 1000+ tasks, all of them start dirtying pages at exactly the same * time, hence all honoured too large initial task->nr_dirtied_pause. */ - p = &__get_cpu_var(bdp_ratelimits); + p = this_cpu_ptr(&bdp_ratelimits); if (unlikely(current->nr_dirtied >= ratelimit)) *p = 0; else if (unlikely(*p >= ratelimit_pages)) { @@ -1640,7 +1617,7 @@ void balance_dirty_pages_ratelimited(struct address_space *mapping) * short-lived tasks (eg. gcc invocations in a kernel build) escaping * the dirty throttling and livelock other long-run dirtiers. */ - p = &__get_cpu_var(dirty_throttle_leaks); + p = this_cpu_ptr(&dirty_throttle_leaks); if (*p > 0 && current->nr_dirtied < ratelimit) { unsigned long nr_pages_dirtied; nr_pages_dirtied = min(*p, ratelimit - current->nr_dirtied); @@ -1687,7 +1664,7 @@ void throttle_vm_writeout(gfp_t gfp_mask) /* * sysctl handler for /proc/sys/vm/dirty_writeback_centisecs */ -int dirty_writeback_centisecs_handler(ctl_table *table, int write, +int dirty_writeback_centisecs_handler(struct ctl_table *table, int write, void __user *buffer, size_t *length, loff_t *ppos) { proc_dointvec(table, write, buffer, length, ppos); @@ -2178,11 +2155,12 @@ int __set_page_dirty_nobuffers(struct page *page) if (!TestSetPageDirty(page)) { struct address_space *mapping = page_mapping(page); struct address_space *mapping2; + unsigned long flags; if (!mapping) return 1; - spin_lock_irq(&mapping->tree_lock); + spin_lock_irqsave(&mapping->tree_lock, flags); mapping2 = page_mapping(page); if (mapping2) { /* Race with truncate? */ BUG_ON(mapping2 != mapping); @@ -2191,7 +2169,7 @@ int __set_page_dirty_nobuffers(struct page *page) radix_tree_tag_set(&mapping->page_tree, page_index(page), PAGECACHE_TAG_DIRTY); } - spin_unlock_irq(&mapping->tree_lock); + spin_unlock_irqrestore(&mapping->tree_lock, flags); if (mapping->host) { /* !PageAnon && !swapper_space */ __mark_inode_dirty(mapping->host, I_DIRTY_PAGES); @@ -2402,7 +2380,7 @@ int test_clear_page_writeback(struct page *page) return ret; } -int test_set_page_writeback(struct page *page) +int __test_set_page_writeback(struct page *page, bool keep_write) { struct address_space *mapping = page_mapping(page); int ret; @@ -2427,9 +2405,10 @@ int test_set_page_writeback(struct page *page) radix_tree_tag_clear(&mapping->page_tree, page_index(page), PAGECACHE_TAG_DIRTY); - radix_tree_tag_clear(&mapping->page_tree, - page_index(page), - PAGECACHE_TAG_TOWRITE); + if (!keep_write) + radix_tree_tag_clear(&mapping->page_tree, + page_index(page), + PAGECACHE_TAG_TOWRITE); spin_unlock_irqrestore(&mapping->tree_lock, flags); } else { ret = TestSetPageWriteback(page); @@ -2440,7 +2419,7 @@ int test_set_page_writeback(struct page *page) return ret; } -EXPORT_SYMBOL(test_set_page_writeback); +EXPORT_SYMBOL(__test_set_page_writeback); /* * Return true if any of the pages in the mapping are marked with the |