From c53919adc045bf803252e912f23028a68525753d Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Tue, 29 May 2012 15:06:19 -0700 Subject: [PATCH] mm: vmscan: remove lumpy reclaim This series removes lumpy reclaim and some stalling logic that was unintentionally being used by memory compaction. The end result is that stalling on dirty pages during page reclaim now depends on wait_iff_congested(). Four kernels were compared 3.3.0 vanilla 3.4.0-rc2 vanilla 3.4.0-rc2 lumpyremove-v2 is patch one from this series 3.4.0-rc2 nosync-v2r3 is the full series Removing lumpy reclaim saves almost 900 bytes of text whereas the full series removes 1200 bytes. text data bss dec hex filename 6740375 1927944 2260992 10929311 a6c49f vmlinux-3.4.0-rc2-vanilla 6739479 1927944 2260992 10928415 a6c11f vmlinux-3.4.0-rc2-lumpyremove-v2 6739159 1927944 2260992 10928095 a6bfdf vmlinux-3.4.0-rc2-nosync-v2 There are behaviour changes in the series and so tests were run with monitoring of ftrace events. This disrupts results so the performance results are distorted but the new behaviour should be clearer. fs-mark running in a threaded configuration showed little of interest as it did not push reclaim aggressively FS-Mark Multi Threaded 3.3.0-vanilla rc2-vanilla lumpyremove-v2r3 nosync-v2r3 Files/s min 3.20 ( 0.00%) 3.20 ( 0.00%) 3.20 ( 0.00%) 3.20 ( 0.00%) Files/s mean 3.20 ( 0.00%) 3.20 ( 0.00%) 3.20 ( 0.00%) 3.20 ( 0.00%) Files/s stddev 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) Files/s max 3.20 ( 0.00%) 3.20 ( 0.00%) 3.20 ( 0.00%) 3.20 ( 0.00%) Overhead min 508667.00 ( 0.00%) 521350.00 (-2.49%) 544292.00 (-7.00%) 547168.00 (-7.57%) Overhead mean 551185.00 ( 0.00%) 652690.73 (-18.42%) 991208.40 (-79.83%) 570130.53 (-3.44%) Overhead stddev 18200.69 ( 0.00%) 331958.29 (-1723.88%) 1579579.43 (-8578.68%) 9576.81 (47.38%) Overhead max 576775.00 ( 0.00%) 1846634.00 (-220.17%) 6901055.00 (-1096.49%) 585675.00 (-1.54%) MMTests Statistics: duration Sys Time Running Test (seconds) 309.90 300.95 307.33 298.95 User+Sys Time Running Test (seconds) 319.32 309.67 315.69 307.51 Total Elapsed Time (seconds) 1187.85 1193.09 1191.98 1193.73 MMTests Statistics: vmstat Page Ins 80532 82212 81420 79480 Page Outs 111434984 111456240 111437376 111582628 Swap Ins 0 0 0 0 Swap Outs 0 0 0 0 Direct pages scanned 44881 27889 27453 34843 Kswapd pages scanned 25841428 25860774 25861233 25843212 Kswapd pages reclaimed 25841393 25860741 25861199 25843179 Direct pages reclaimed 44881 27889 27453 34843 Kswapd efficiency 99% 99% 99% 99% Kswapd velocity 21754.791 21675.460 21696.029 21649.127 Direct efficiency 100% 100% 100% 100% Direct velocity 37.783 23.375 23.031 29.188 Percentage direct scans 0% 0% 0% 0% ftrace showed that there was no stalling on writeback or pages submitted for IO from reclaim context. postmark was similar and while it was more interesting, it also did not push reclaim heavily. POSTMARK 3.3.0-vanilla rc2-vanilla lumpyremove-v2r3 nosync-v2r3 Transactions per second: 16.00 ( 0.00%) 20.00 (25.00%) 18.00 (12.50%) 17.00 ( 6.25%) Data megabytes read per second: 18.80 ( 0.00%) 24.27 (29.10%) 22.26 (18.40%) 20.54 ( 9.26%) Data megabytes written per second: 35.83 ( 0.00%) 46.25 (29.08%) 42.42 (18.39%) 39.14 ( 9.24%) Files created alone per second: 28.00 ( 0.00%) 38.00 (35.71%) 34.00 (21.43%) 30.00 ( 7.14%) Files create/transact per second: 8.00 ( 0.00%) 10.00 (25.00%) 9.00 (12.50%) 8.00 ( 0.00%) Files deleted alone per second: 556.00 ( 0.00%) 1224.00 (120.14%) 3062.00 (450.72%) 6124.00 (1001.44%) Files delete/transact per second: 8.00 ( 0.00%) 10.00 (25.00%) 9.00 (12.50%) 8.00 ( 0.00%) MMTests Statistics: duration Sys Time Running Test (seconds) 113.34 107.99 109.73 108.72 User+Sys Time Running Test (seconds) 145.51 139.81 143.32 143.55 Total Elapsed Time (seconds) 1159.16 899.23 980.17 1062.27 MMTests Statistics: vmstat Page Ins 13710192 13729032 13727944 13760136 Page Outs 43071140 42987228 42733684 42931624 Swap Ins 0 0 0 0 Swap Outs 0 0 0 0 Direct pages scanned 0 0 0 0 Kswapd pages scanned 9941613 9937443 9939085 9929154 Kswapd pages reclaimed 9940926 9936751 9938397 9928465 Direct pages reclaimed 0 0 0 0 Kswapd efficiency 99% 99% 99% 99% Kswapd velocity 8576.567 11051.058 10140.164 9347.109 Direct efficiency 100% 100% 100% 100% Direct velocity 0.000 0.000 0.000 0.000 It looks like here that the full series regresses performance but as ftrace showed no usage of wait_iff_congested() or sync reclaim I am assuming it's a disruption due to monitoring. Other data such as memory usage, page IO, swap IO all looked similar. Running a benchmark with a plain DD showed nothing very interesting. The full series stalled in wait_iff_congested() slightly less but stall times on vanilla kernels were marginal. Running a benchmark that hammered on file-backed mappings showed stalls due to congestion but not in sync writebacks MICRO 3.3.0-vanilla rc2-vanilla lumpyremove-v2r3 nosync-v2r3 MMTests Statistics: duration Sys Time Running Test (seconds) 308.13 294.50 298.75 299.53 User+Sys Time Running Test (seconds) 330.45 316.28 318.93 320.79 Total Elapsed Time (seconds) 1814.90 1833.88 1821.14 1832.91 MMTests Statistics: vmstat Page Ins 108712 120708 97224 110344 Page Outs 155514576 156017404 155813676 156193256 Swap Ins 0 0 0 0 Swap Outs 0 0 0 0 Direct pages scanned 2599253 1550480 2512822 2414760 Kswapd pages scanned 69742364 71150694 68839041 69692533 Kswapd pages reclaimed 34824488 34773341 34796602 34799396 Direct pages reclaimed 53693 94750 61792 75205 Kswapd efficiency 49% 48% 50% 49% Kswapd velocity 38427.662 38797.901 37799.972 38022.889 Direct efficiency 2% 6% 2% 3% Direct velocity 1432.174 845.464 1379.807 1317.446 Percentage direct scans 3% 2% 3% 3% Page writes by reclaim 0 0 0 0 Page writes file 0 0 0 0 Page writes anon 0 0 0 0 Page reclaim immediate 0 0 0 1218 Page rescued immediate 0 0 0 0 Slabs scanned 15360 16384 13312 16384 Direct inode steals 0 0 0 0 Kswapd inode steals 4340 4327 1630 4323 FTrace Reclaim Statistics: congestion_wait Direct number congest waited 0 0 0 0 Direct time congest waited 0ms 0ms 0ms 0ms Direct full congest waited 0 0 0 0 Direct number conditional waited 900 870 754 789 Direct time conditional waited 0ms 0ms 0ms 20ms Direct full conditional waited 0 0 0 0 KSwapd number congest waited 2106 2308 2116 1915 KSwapd time congest waited 139924ms 157832ms 125652ms 132516ms KSwapd full congest waited 1346 1530 1202 1278 KSwapd number conditional waited 12922 16320 10943 14670 KSwapd time conditional waited 0ms 0ms 0ms 0ms KSwapd full conditional waited 0 0 0 0 Reclaim statistics are not radically changed. The stall times in kswapd are massive but it is clear that it is due to calls to congestion_wait() and that is almost certainly the call in balance_pgdat(). Otherwise stalls due to dirty pages are non-existant. I ran a benchmark that stressed high-order allocation. This is very artifical load but was used in the past to evaluate lumpy reclaim and compaction. Generally I look at allocation success rates and latency figures. STRESS-HIGHALLOC 3.3.0-vanilla rc2-vanilla lumpyremove-v2r3 nosync-v2r3 Pass 1 81.00 ( 0.00%) 28.00 (-53.00%) 24.00 (-57.00%) 28.00 (-53.00%) Pass 2 82.00 ( 0.00%) 39.00 (-43.00%) 38.00 (-44.00%) 43.00 (-39.00%) while Rested 88.00 ( 0.00%) 87.00 (-1.00%) 88.00 ( 0.00%) 88.00 ( 0.00%) MMTests Statistics: duration Sys Time Running Test (seconds) 740.93 681.42 685.14 684.87 User+Sys Time Running Test (seconds) 2922.65 3269.52 3281.35 3279.44 Total Elapsed Time (seconds) 1161.73 1152.49 1159.55 1161.44 MMTests Statistics: vmstat Page Ins 4486020 2807256 2855944 2876244 Page Outs 7261600 7973688 7975320 7986120 Swap Ins 31694 0 0 0 Swap Outs 98179 0 0 0 Direct pages scanned 53494 57731 34406 113015 Kswapd pages scanned 6271173 1287481 1278174 1219095 Kswapd pages reclaimed 2029240 1281025 1260708 1201583 Direct pages reclaimed 1468 14564 16649 92456 Kswapd efficiency 32% 99% 98% 98% Kswapd velocity 5398.133 1117.130 1102.302 1049.641 Direct efficiency 2% 25% 48% 81% Direct velocity 46.047 50.092 29.672 97.306 Percentage direct scans 0% 4% 2% 8% Page writes by reclaim 1616049 0 0 0 Page writes file 1517870 0 0 0 Page writes anon 98179 0 0 0 Page reclaim immediate 103778 27339 9796 17831 Page rescued immediate 0 0 0 0 Slabs scanned 1096704 986112 980992 998400 Direct inode steals 223 215040 216736 247881 Kswapd inode steals 175331 61548 68444 63066 Kswapd skipped wait 21991 0 1 0 THP fault alloc 1 135 125 134 THP collapse alloc 393 311 228 236 THP splits 25 13 7 8 THP fault fallback 0 0 0 0 THP collapse fail 3 5 7 7 Compaction stalls 865 1270 1422 1518 Compaction success 370 401 353 383 Compaction failures 495 869 1069 1135 Compaction pages moved 870155 3828868 4036106 4423626 Compaction move failure 26429 23865 29742 27514 Success rates are completely hosed for 3.4-rc2 which is almost certainly due to commit fe2c2a106663 ("vmscan: reclaim at order 0 when compaction is enabled"). I expected this would happen for kswapd and impair allocation success rates (https://lkml.org/lkml/2012/1/25/166) but I did not anticipate this much a difference: 80% less scanning, 37% less reclaim by kswapd In comparison, reclaim/compaction is not aggressive and gives up easily which is the intended behaviour. hugetlbfs uses __GFP_REPEAT and would be much more aggressive about reclaim/compaction than THP allocations are. The stress test above is allocating like neither THP or hugetlbfs but is much closer to THP. Mainline is now impaired in terms of high order allocation under heavy load although I do not know to what degree as I did not test with __GFP_REPEAT. Keep this in mind for bugs related to hugepage pool resizing, THP allocation and high order atomic allocation failures from network devices. In terms of congestion throttling, I see the following for this test FTrace Reclaim Statistics: congestion_wait Direct number congest waited 3 0 0 0 Direct time congest waited 0ms 0ms 0ms 0ms Direct full congest waited 0 0 0 0 Direct number conditional waited 957 512 1081 1075 Direct time conditional waited 0ms 0ms 0ms 0ms Direct full conditional waited 0 0 0 0 KSwapd number congest waited 36 4 3 5 KSwapd time congest waited 3148ms 400ms 300ms 500ms KSwapd full congest waited 30 4 3 5 KSwapd number conditional waited 88514 197 332 542 KSwapd time conditional waited 4980ms 0ms 0ms 0ms KSwapd full conditional waited 49 0 0 0 The "conditional waited" times are the most interesting as this is directly impacted by the number of dirty pages encountered during scan. As lumpy reclaim is no longer scanning contiguous ranges, it is finding fewer dirty pages. This brings wait times from about 5 seconds to 0. kswapd itself is still calling congestion_wait() so it'll still stall but it's a lot less. In terms of the type of IO we were doing, I see this FTrace Reclaim Statistics: mm_vmscan_writepage Direct writes anon sync 0 0 0 0 Direct writes anon async 0 0 0 0 Direct writes file sync 0 0 0 0 Direct writes file async 0 0 0 0 Direct writes mixed sync 0 0 0 0 Direct writes mixed async 0 0 0 0 KSwapd writes anon sync 0 0 0 0 KSwapd writes anon async 91682 0 0 0 KSwapd writes file sync 0 0 0 0 KSwapd writes file async 822629 0 0 0 KSwapd writes mixed sync 0 0 0 0 KSwapd writes mixed async 0 0 0 0 In 3.2, kswapd was doing a bunch of async writes of pages but reclaim/compaction was never reaching a point where it was doing sync IO. This does not guarantee that reclaim/compaction was not calling wait_on_page_writeback() but I would consider it unlikely. It indicates that merging patches 2 and 3 to stop reclaim/compaction calling wait_on_page_writeback() should be safe. This patch: Lumpy reclaim had a purpose but in the mind of some, it was to kick the system so hard it trashed. For others the purpose was to complicate vmscan.c. Over time it was giving softer shoes and a nicer attitude but memory compaction needs to step up and replace it so this patch sends lumpy reclaim to the farm. The tracepoint format changes for isolating LRU pages with this patch applied. Furthermore reclaim/compaction can no longer queue dirty pages in pageout() if the underlying BDI is congested. Lumpy reclaim used this logic and reclaim/compaction was using it in error. Signed-off-by: Mel Gorman Acked-by: Rik van Riel Acked-by: KOSAKI Motohiro Cc: Konstantin Khlebnikov Cc: Hugh Dickins Cc: Ying Han Cc: Andy Whitcroft Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/trace/events/vmscan.h | 26 +----- mm/vmscan.c | 144 ++++------------------------------ 2 files changed, 19 insertions(+), 151 deletions(-) diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h index 572195459d5..bdaf32f8a87 100644 --- a/include/trace/events/vmscan.h +++ b/include/trace/events/vmscan.h @@ -263,22 +263,16 @@ DECLARE_EVENT_CLASS(mm_vmscan_lru_isolate_template, unsigned long nr_requested, unsigned long nr_scanned, unsigned long nr_taken, - unsigned long nr_lumpy_taken, - unsigned long nr_lumpy_dirty, - unsigned long nr_lumpy_failed, isolate_mode_t isolate_mode, int file), - TP_ARGS(order, nr_requested, nr_scanned, nr_taken, nr_lumpy_taken, nr_lumpy_dirty, nr_lumpy_failed, isolate_mode, file), + TP_ARGS(order, nr_requested, nr_scanned, nr_taken, isolate_mode, file), TP_STRUCT__entry( __field(int, order) __field(unsigned long, nr_requested) __field(unsigned long, nr_scanned) __field(unsigned long, nr_taken) - __field(unsigned long, nr_lumpy_taken) - __field(unsigned long, nr_lumpy_dirty) - __field(unsigned long, nr_lumpy_failed) __field(isolate_mode_t, isolate_mode) __field(int, file) ), @@ -288,22 +282,16 @@ DECLARE_EVENT_CLASS(mm_vmscan_lru_isolate_template, __entry->nr_requested = nr_requested; __entry->nr_scanned = nr_scanned; __entry->nr_taken = nr_taken; - __entry->nr_lumpy_taken = nr_lumpy_taken; - __entry->nr_lumpy_dirty = nr_lumpy_dirty; - __entry->nr_lumpy_failed = nr_lumpy_failed; __entry->isolate_mode = isolate_mode; __entry->file = file; ), - TP_printk("isolate_mode=%d order=%d nr_requested=%lu nr_scanned=%lu nr_taken=%lu contig_taken=%lu contig_dirty=%lu contig_failed=%lu file=%d", + TP_printk("isolate_mode=%d order=%d nr_requested=%lu nr_scanned=%lu nr_taken=%lu file=%d", __entry->isolate_mode, __entry->order, __entry->nr_requested, __entry->nr_scanned, __entry->nr_taken, - __entry->nr_lumpy_taken, - __entry->nr_lumpy_dirty, - __entry->nr_lumpy_failed, __entry->file) ); @@ -313,13 +301,10 @@ DEFINE_EVENT(mm_vmscan_lru_isolate_template, mm_vmscan_lru_isolate, unsigned long nr_requested, unsigned long nr_scanned, unsigned long nr_taken, - unsigned long nr_lumpy_taken, - unsigned long nr_lumpy_dirty, - unsigned long nr_lumpy_failed, isolate_mode_t isolate_mode, int file), - TP_ARGS(order, nr_requested, nr_scanned, nr_taken, nr_lumpy_taken, nr_lumpy_dirty, nr_lumpy_failed, isolate_mode, file) + TP_ARGS(order, nr_requested, nr_scanned, nr_taken, isolate_mode, file) ); @@ -329,13 +314,10 @@ DEFINE_EVENT(mm_vmscan_lru_isolate_template, mm_vmscan_memcg_isolate, unsigned long nr_requested, unsigned long nr_scanned, unsigned long nr_taken, - unsigned long nr_lumpy_taken, - unsigned long nr_lumpy_dirty, - unsigned long nr_lumpy_failed, isolate_mode_t isolate_mode, int file), - TP_ARGS(order, nr_requested, nr_scanned, nr_taken, nr_lumpy_taken, nr_lumpy_dirty, nr_lumpy_failed, isolate_mode, file) + TP_ARGS(order, nr_requested, nr_scanned, nr_taken, isolate_mode, file) ); diff --git a/mm/vmscan.c b/mm/vmscan.c index ca46080bb07..546d02ce90e 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -58,9 +58,6 @@ * RECLAIM_MODE_SINGLE: Reclaim only order-0 pages * RECLAIM_MODE_ASYNC: Do not block * RECLAIM_MODE_SYNC: Allow blocking e.g. call wait_on_page_writeback - * RECLAIM_MODE_LUMPYRECLAIM: For high-order allocations, take a reference - * page from the LRU and reclaim all pages within a - * naturally aligned range * RECLAIM_MODE_COMPACTION: For high-order allocations, reclaim a number of * order-0 pages and then compact the zone */ @@ -68,7 +65,6 @@ typedef unsigned __bitwise__ reclaim_mode_t; #define RECLAIM_MODE_SINGLE ((__force reclaim_mode_t)0x01u) #define RECLAIM_MODE_ASYNC ((__force reclaim_mode_t)0x02u) #define RECLAIM_MODE_SYNC ((__force reclaim_mode_t)0x04u) -#define RECLAIM_MODE_LUMPYRECLAIM ((__force reclaim_mode_t)0x08u) #define RECLAIM_MODE_COMPACTION ((__force reclaim_mode_t)0x10u) struct scan_control { @@ -367,27 +363,17 @@ out: static void set_reclaim_mode(int priority, struct scan_control *sc, bool sync) { + /* Sync reclaim used only for compaction */ reclaim_mode_t syncmode = sync ? RECLAIM_MODE_SYNC : RECLAIM_MODE_ASYNC; /* - * Initially assume we are entering either lumpy reclaim or - * reclaim/compaction.Depending on the order, we will either set the - * sync mode or just reclaim order-0 pages later. - */ - if (COMPACTION_BUILD) - sc->reclaim_mode = RECLAIM_MODE_COMPACTION; - else - sc->reclaim_mode = RECLAIM_MODE_LUMPYRECLAIM; - - /* - * Avoid using lumpy reclaim or reclaim/compaction if possible by - * restricting when its set to either costly allocations or when + * Restrict reclaim/compaction to costly allocations or when * under memory pressure */ - if (sc->order > PAGE_ALLOC_COSTLY_ORDER) - sc->reclaim_mode |= syncmode; - else if (sc->order && priority < DEF_PRIORITY - 2) - sc->reclaim_mode |= syncmode; + if (COMPACTION_BUILD && sc->order && + (sc->order > PAGE_ALLOC_COSTLY_ORDER || + priority < DEF_PRIORITY - 2)) + sc->reclaim_mode = RECLAIM_MODE_COMPACTION | syncmode; else sc->reclaim_mode = RECLAIM_MODE_SINGLE | RECLAIM_MODE_ASYNC; } @@ -416,10 +402,6 @@ static int may_write_to_queue(struct backing_dev_info *bdi, return 1; if (bdi == current->backing_dev_info) return 1; - - /* lumpy reclaim for hugepage often need a lot of write */ - if (sc->order > PAGE_ALLOC_COSTLY_ORDER) - return 1; return 0; } @@ -710,10 +692,6 @@ static enum page_references page_check_references(struct page *page, referenced_ptes = page_referenced(page, 1, mz->mem_cgroup, &vm_flags); referenced_page = TestClearPageReferenced(page); - /* Lumpy reclaim - ignore references */ - if (sc->reclaim_mode & RECLAIM_MODE_LUMPYRECLAIM) - return PAGEREF_RECLAIM; - /* * Mlock lost the isolation race with us. Let try_to_unmap() * move the page to the unevictable list. @@ -824,7 +802,7 @@ static unsigned long shrink_page_list(struct list_head *page_list, wait_on_page_writeback(page); else { unlock_page(page); - goto keep_lumpy; + goto keep_reclaim_mode; } } @@ -908,7 +886,7 @@ static unsigned long shrink_page_list(struct list_head *page_list, goto activate_locked; case PAGE_SUCCESS: if (PageWriteback(page)) - goto keep_lumpy; + goto keep_reclaim_mode; if (PageDirty(page)) goto keep; @@ -1008,7 +986,7 @@ keep_locked: unlock_page(page); keep: reset_reclaim_mode(sc); -keep_lumpy: +keep_reclaim_mode: list_add(&page->lru, &ret_pages); VM_BUG_ON(PageLRU(page) || PageUnevictable(page)); } @@ -1064,11 +1042,7 @@ int __isolate_lru_page(struct page *page, isolate_mode_t mode, int file) if (!all_lru_mode && !!page_is_file_cache(page) != file) return ret; - /* - * When this function is being called for lumpy reclaim, we - * initially look into all LRU pages, active, inactive and - * unevictable; only give shrink_page_list evictable pages. - */ + /* Do not give back unevictable pages for compaction */ if (PageUnevictable(page)) return ret; @@ -1153,9 +1127,6 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan, struct lruvec *lruvec; struct list_head *src; unsigned long nr_taken = 0; - unsigned long nr_lumpy_taken = 0; - unsigned long nr_lumpy_dirty = 0; - unsigned long nr_lumpy_failed = 0; unsigned long scan; int lru = LRU_BASE; @@ -1168,10 +1139,6 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan, for (scan = 0; scan < nr_to_scan && !list_empty(src); scan++) { struct page *page; - unsigned long pfn; - unsigned long end_pfn; - unsigned long page_pfn; - int zone_id; page = lru_to_page(src); prefetchw_prev_lru_page(page, src, flags); @@ -1193,84 +1160,6 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan, default: BUG(); } - - if (!sc->order || !(sc->reclaim_mode & RECLAIM_MODE_LUMPYRECLAIM)) - continue; - - /* - * Attempt to take all pages in the order aligned region - * surrounding the tag page. Only take those pages of - * the same active state as that tag page. We may safely - * round the target page pfn down to the requested order - * as the mem_map is guaranteed valid out to MAX_ORDER, - * where that page is in a different zone we will detect - * it from its zone id and abort this block scan. - */ - zone_id = page_zone_id(page); - page_pfn = page_to_pfn(page); - pfn = page_pfn & ~((1 << sc->order) - 1); - end_pfn = pfn + (1 << sc->order); - for (; pfn < end_pfn; pfn++) { - struct page *cursor_page; - - /* The target page is in the block, ignore it. */ - if (unlikely(pfn == page_pfn)) - continue; - - /* Avoid holes within the zone. */ - if (unlikely(!pfn_valid_within(pfn))) - break; - - cursor_page = pfn_to_page(pfn); - - /* Check that we have not crossed a zone boundary. */ - if (unlikely(page_zone_id(cursor_page) != zone_id)) - break; - - /* - * If we don't have enough swap space, reclaiming of - * anon page which don't already have a swap slot is - * pointless. - */ - if (nr_swap_pages <= 0 && PageSwapBacked(cursor_page) && - !PageSwapCache(cursor_page)) - break; - - if (__isolate_lru_page(cursor_page, mode, file) == 0) { - unsigned int isolated_pages; - - mem_cgroup_lru_del(cursor_page); - list_move(&cursor_page->lru, dst); - isolated_pages = hpage_nr_pages(cursor_page); - nr_taken += isolated_pages; - nr_lumpy_taken += isolated_pages; - if (PageDirty(cursor_page)) - nr_lumpy_dirty += isolated_pages; - scan++; - pfn += isolated_pages - 1; - } else { - /* - * Check if the page is freed already. - * - * We can't use page_count() as that - * requires compound_head and we don't - * have a pin on the page here. If a - * page is tail, we may or may not - * have isolated the head, so assume - * it's not free, it'd be tricky to - * track the head status without a - * page pin. - */ - if (!PageTail(cursor_page) && - !atomic_read(&cursor_page->_count)) - continue; - break; - } - } - - /* If we break out of the loop above, lumpy reclaim failed */ - if (pfn < end_pfn) - nr_lumpy_failed++; } *nr_scanned = scan; @@ -1278,7 +1167,6 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan, trace_mm_vmscan_lru_isolate(sc->order, nr_to_scan, scan, nr_taken, - nr_lumpy_taken, nr_lumpy_dirty, nr_lumpy_failed, mode, file); return nr_taken; } @@ -1466,13 +1354,13 @@ static inline bool should_reclaim_stall(unsigned long nr_taken, int priority, struct scan_control *sc) { - int lumpy_stall_priority; + int stall_priority; /* kswapd should not stall on sync IO */ if (current_is_kswapd()) return false; - /* Only stall on lumpy reclaim */ + /* Only stall for memory compaction */ if (sc->reclaim_mode & RECLAIM_MODE_SINGLE) return false; @@ -1487,11 +1375,11 @@ static inline bool should_reclaim_stall(unsigned long nr_taken, * priority to be much higher before stalling. */ if (sc->order > PAGE_ALLOC_COSTLY_ORDER) - lumpy_stall_priority = DEF_PRIORITY; + stall_priority = DEF_PRIORITY; else - lumpy_stall_priority = DEF_PRIORITY / 3; + stall_priority = DEF_PRIORITY / 3; - return priority <= lumpy_stall_priority; + return priority <= stall_priority; } /* @@ -1523,8 +1411,6 @@ shrink_inactive_list(unsigned long nr_to_scan, struct mem_cgroup_zone *mz, } set_reclaim_mode(priority, sc, false); - if (sc->reclaim_mode & RECLAIM_MODE_LUMPYRECLAIM) - isolate_mode |= ISOLATE_ACTIVE; lru_add_drain(); -- 2.20.1