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author | Johannes Weiner <hannes@cmpxchg.org> | 2012-01-10 15:06:57 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-01-10 16:30:41 -0800 |
commit | 1edf223485c42c99655dcd001db1e46ad5e5d2d7 (patch) | |
tree | 33b93dc8f2a249806150b5792ac1787688bf6b74 /mm | |
parent | e4e11180dfa545233e5145919b75b7fac88638df (diff) | |
download | op-kernel-dev-1edf223485c42c99655dcd001db1e46ad5e5d2d7.zip op-kernel-dev-1edf223485c42c99655dcd001db1e46ad5e5d2d7.tar.gz |
mm/page-writeback.c: make determine_dirtyable_memory static again
The tracing ring-buffer used this function briefly, but not anymore.
Make it local to the writeback code again.
Also, move the function so that no forward declaration needs to be
reintroduced.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r-- | mm/page-writeback.c | 122 |
1 files changed, 60 insertions, 62 deletions
diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 8616ef3..c081bf6 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -130,6 +130,66 @@ unsigned long global_dirty_limit; static struct prop_descriptor vm_completions; /* + * 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. + */ +static unsigned long highmem_dirtyable_memory(unsigned long total) +{ +#ifdef CONFIG_HIGHMEM + int node; + unsigned long x = 0; + + for_each_node_state(node, N_HIGH_MEMORY) { + struct zone *z = + &NODE_DATA(node)->node_zones[ZONE_HIGHMEM]; + + x += zone_page_state(z, NR_FREE_PAGES) + + zone_reclaimable_pages(z); + } + /* + * Make sure that the number of highmem pages is never larger + * than the number of the total dirtyable memory. This can only + * occur in very strange VM situations but we want to make sure + * that this does not occur. + */ + return min(x, total); +#else + return 0; +#endif +} + +/** + * determine_dirtyable_memory - amount of memory that may be used + * + * Returns the numebr of pages that can currently be freed and used + * by the kernel for direct mappings. + */ +static unsigned long determine_dirtyable_memory(void) +{ + unsigned long x; + + x = global_page_state(NR_FREE_PAGES) + global_reclaimable_pages(); + + if (!vm_highmem_is_dirtyable) + x -= highmem_dirtyable_memory(x); + + return x + 1; /* Ensure that we never return 0 */ +} + +/* * couple the period to the dirty_ratio: * * period/2 ~ roundup_pow_of_two(dirty limit) @@ -196,7 +256,6 @@ int dirty_ratio_handler(struct ctl_table *table, int write, return ret; } - int dirty_bytes_handler(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) @@ -291,67 +350,6 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned max_ratio) } EXPORT_SYMBOL(bdi_set_max_ratio); -/* - * 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. - */ - -static unsigned long highmem_dirtyable_memory(unsigned long total) -{ -#ifdef CONFIG_HIGHMEM - int node; - unsigned long x = 0; - - for_each_node_state(node, N_HIGH_MEMORY) { - struct zone *z = - &NODE_DATA(node)->node_zones[ZONE_HIGHMEM]; - - x += zone_page_state(z, NR_FREE_PAGES) + - zone_reclaimable_pages(z); - } - /* - * Make sure that the number of highmem pages is never larger - * than the number of the total dirtyable memory. This can only - * occur in very strange VM situations but we want to make sure - * that this does not occur. - */ - return min(x, total); -#else - return 0; -#endif -} - -/** - * determine_dirtyable_memory - amount of memory that may be used - * - * Returns the numebr of pages that can currently be freed and used - * by the kernel for direct mappings. - */ -unsigned long determine_dirtyable_memory(void) -{ - unsigned long x; - - x = global_page_state(NR_FREE_PAGES) + global_reclaimable_pages(); - - if (!vm_highmem_is_dirtyable) - x -= highmem_dirtyable_memory(x); - - return x + 1; /* Ensure that we never return 0 */ -} - static unsigned long dirty_freerun_ceiling(unsigned long thresh, unsigned long bg_thresh) { |