From b2e185384f534781fd22f5ce170b2ad26f97df70 Mon Sep 17 00:00:00 2001 From: Rik van Riel Date: Sat, 18 Oct 2008 20:26:30 -0700 Subject: define page_file_cache() function Define page_file_cache() function to answer the question: is page backed by a file? Originally part of Rik van Riel's split-lru patch. Extracted to make available for other, independent reclaim patches. Moved inline function to linux/mm_inline.h where it will be needed by subsequent "split LRU" and "noreclaim" patches. Unfortunately this needs to use a page flag, since the PG_swapbacked state needs to be preserved all the way to the point where the page is last removed from the LRU. Trying to derive the status from other info in the page resulted in wrong VM statistics in earlier split VM patchsets. The total number of page flags in use on a 32 bit machine after this patch is 19. [akpm@linux-foundation.org: fix up out-of-order merge fallout] [hugh@veritas.com: splitlru: shmem_getpage SetPageSwapBacked sooner[ Signed-off-by: Rik van Riel Signed-off-by: Lee Schermerhorn Signed-off-by: MinChan Kim Signed-off-by: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/swap_state.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'mm/swap_state.c') diff --git a/mm/swap_state.c b/mm/swap_state.c index 797c3831cbe..7a3ece0b5a3 100644 --- a/mm/swap_state.c +++ b/mm/swap_state.c @@ -75,6 +75,7 @@ int add_to_swap_cache(struct page *page, swp_entry_t entry, gfp_t gfp_mask) BUG_ON(!PageLocked(page)); BUG_ON(PageSwapCache(page)); BUG_ON(PagePrivate(page)); + BUG_ON(!PageSwapBacked(page)); error = radix_tree_preload(gfp_mask); if (!error) { page_cache_get(page); @@ -303,6 +304,7 @@ struct page *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, * May fail (-ENOMEM) if radix-tree node allocation failed. */ set_page_locked(new_page); + SetPageSwapBacked(new_page); err = add_to_swap_cache(new_page, entry, gfp_mask & GFP_KERNEL); if (likely(!err)) { /* @@ -312,6 +314,7 @@ struct page *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, swap_readpage(NULL, new_page); return new_page; } + ClearPageSwapBacked(new_page); clear_page_locked(new_page); swap_free(entry); } while (err != -ENOMEM); -- cgit From 4f98a2fee8acdb4ac84545df98cccecfd130f8db Mon Sep 17 00:00:00 2001 From: Rik van Riel Date: Sat, 18 Oct 2008 20:26:32 -0700 Subject: vmscan: split LRU lists into anon & file sets Split the LRU lists in two, one set for pages that are backed by real file systems ("file") and one for pages that are backed by memory and swap ("anon"). The latter includes tmpfs. The advantage of doing this is that the VM will not have to scan over lots of anonymous pages (which we generally do not want to swap out), just to find the page cache pages that it should evict. This patch has the infrastructure and a basic policy to balance how much we scan the anon lists and how much we scan the file lists. The big policy changes are in separate patches. [lee.schermerhorn@hp.com: collect lru meminfo statistics from correct offset] [kosaki.motohiro@jp.fujitsu.com: prevent incorrect oom under split_lru] [kosaki.motohiro@jp.fujitsu.com: fix pagevec_move_tail() doesn't treat unevictable page] [hugh@veritas.com: memcg swapbacked pages active] [hugh@veritas.com: splitlru: BDI_CAP_SWAP_BACKED] [akpm@linux-foundation.org: fix /proc/vmstat units] [nishimura@mxp.nes.nec.co.jp: memcg: fix handling of shmem migration] [kosaki.motohiro@jp.fujitsu.com: adjust Quicklists field of /proc/meminfo] [kosaki.motohiro@jp.fujitsu.com: fix style issue of get_scan_ratio()] Signed-off-by: Rik van Riel Signed-off-by: Lee Schermerhorn Signed-off-by: KOSAKI Motohiro Signed-off-by: Hugh Dickins Signed-off-by: Daisuke Nishimura Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/swap_state.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'mm/swap_state.c') diff --git a/mm/swap_state.c b/mm/swap_state.c index 7a3ece0b5a3..ea62084ed40 100644 --- a/mm/swap_state.c +++ b/mm/swap_state.c @@ -33,7 +33,7 @@ static const struct address_space_operations swap_aops = { }; static struct backing_dev_info swap_backing_dev_info = { - .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK, + .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK | BDI_CAP_SWAP_BACKED, .unplug_io_fn = swap_unplug_io_fn, }; @@ -310,7 +310,7 @@ struct page *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, /* * Initiate read into locked page and return. */ - lru_cache_add_active(new_page); + lru_cache_add_active_anon(new_page); swap_readpage(NULL, new_page); return new_page; } -- cgit From c5fdae469a6a26cd882d7fe0aa3fbfffb6b72fc5 Mon Sep 17 00:00:00 2001 From: Rik van Riel Date: Sat, 18 Oct 2008 20:26:36 -0700 Subject: vmscan: add newly swapped in pages to the inactive list Swapin_readahead can read in a lot of data that the processes in memory never need. Adding swap cache pages to the inactive list prevents them from putting too much pressure on the working set. This has the potential to help the programs that are already in memory, but it could also be a disadvantage to processes that are trying to get swapped in. Signed-off-by: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/swap_state.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm/swap_state.c') diff --git a/mm/swap_state.c b/mm/swap_state.c index ea62084ed40..43cda7b4b80 100644 --- a/mm/swap_state.c +++ b/mm/swap_state.c @@ -310,7 +310,7 @@ struct page *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, /* * Initiate read into locked page and return. */ - lru_cache_add_active_anon(new_page); + lru_cache_add_anon(new_page); swap_readpage(NULL, new_page); return new_page; } -- cgit From f45840b5c128445da70e7ec33adc47b4a12bdaf4 Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Sat, 18 Oct 2008 20:26:57 -0700 Subject: mm: pagecache insertion fewer atomics Setting and clearing the page locked when inserting it into swapcache / pagecache when it has no other references can use non-atomic page flags operations because no other CPU may be operating on it at this time. This saves one atomic operation when inserting a page into pagecache. Signed-off-by: Nick Piggin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/swap_state.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'mm/swap_state.c') diff --git a/mm/swap_state.c b/mm/swap_state.c index 43cda7b4b80..3353c9029ce 100644 --- a/mm/swap_state.c +++ b/mm/swap_state.c @@ -303,7 +303,7 @@ struct page *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, * re-using the just freed swap entry for an existing page. * May fail (-ENOMEM) if radix-tree node allocation failed. */ - set_page_locked(new_page); + __set_page_locked(new_page); SetPageSwapBacked(new_page); err = add_to_swap_cache(new_page, entry, gfp_mask & GFP_KERNEL); if (likely(!err)) { @@ -315,7 +315,7 @@ struct page *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, return new_page; } ClearPageSwapBacked(new_page); - clear_page_locked(new_page); + __clear_page_locked(new_page); swap_free(entry); } while (err != -ENOMEM); -- cgit