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FROMLIST: mm/vmscan.c: refactor shrink_node()
This patch refactors shrink_node() to improve readability for the upcoming changes to mm/vmscan.c. Link: https://lore.kernel.org/r/20220309021230.721028-4-yuzhao@google.com/ Signed-off-by: Yu Zhao <yuzhao@google.com> Reviewed-by: Barry Song <baohua@kernel.org> Acked-by: Brian Geffon <bgeffon@google.com> Acked-by: Jan Alexander Steffens (heftig) <heftig@archlinux.org> Acked-by: Oleksandr Natalenko <oleksandr@natalenko.name> Acked-by: Steven Barrett <steven@liquorix.net> Acked-by: Suleiman Souhlal <suleiman@google.com> Tested-by: Daniel Byrne <djbyrne@mtu.edu> Tested-by: Donald Carr <d@chaos-reins.com> Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com> Tested-by: Konstantin Kharlamov <Hi-Angel@yandex.ru> Tested-by: Shuang Zhai <szhai2@cs.rochester.edu> Tested-by: Sofia Trinh <sofia.trinh@edi.works> Tested-by: Vaibhav Jain <vaibhav@linux.ibm.com> Bug: 227651406 Signed-off-by: Kalesh Singh <kaleshsingh@google.com> Change-Id: I186f43f946de0d40d54883fb31114840fc749a57
This commit is contained in:
186
mm/vmscan.c
186
mm/vmscan.c
@@ -2282,6 +2282,103 @@ enum scan_balance {
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SCAN_FILE,
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};
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static void prepare_scan_count(pg_data_t *pgdat, struct scan_control *sc)
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{
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unsigned long file;
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struct lruvec *target_lruvec;
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target_lruvec = mem_cgroup_lruvec(sc->target_mem_cgroup, pgdat);
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/*
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* Determine the scan balance between anon and file LRUs.
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*/
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spin_lock_irq(&pgdat->lru_lock);
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sc->anon_cost = target_lruvec->anon_cost;
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sc->file_cost = target_lruvec->file_cost;
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spin_unlock_irq(&pgdat->lru_lock);
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/*
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* Target desirable inactive:active list ratios for the anon
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* and file LRU lists.
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*/
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if (!sc->force_deactivate) {
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unsigned long refaults;
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refaults = lruvec_page_state(target_lruvec,
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WORKINGSET_ACTIVATE_ANON);
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if (refaults != target_lruvec->refaults[0] ||
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inactive_is_low(target_lruvec, LRU_INACTIVE_ANON))
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sc->may_deactivate |= DEACTIVATE_ANON;
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else
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sc->may_deactivate &= ~DEACTIVATE_ANON;
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/*
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* When refaults are being observed, it means a new
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* workingset is being established. Deactivate to get
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* rid of any stale active pages quickly.
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*/
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refaults = lruvec_page_state(target_lruvec,
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WORKINGSET_ACTIVATE_FILE);
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if (refaults != target_lruvec->refaults[1] ||
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inactive_is_low(target_lruvec, LRU_INACTIVE_FILE))
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sc->may_deactivate |= DEACTIVATE_FILE;
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else
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sc->may_deactivate &= ~DEACTIVATE_FILE;
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} else
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sc->may_deactivate = DEACTIVATE_ANON | DEACTIVATE_FILE;
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/*
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* If we have plenty of inactive file pages that aren't
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* thrashing, try to reclaim those first before touching
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* anonymous pages.
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*/
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file = lruvec_page_state(target_lruvec, NR_INACTIVE_FILE);
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if (file >> sc->priority && !(sc->may_deactivate & DEACTIVATE_FILE))
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sc->cache_trim_mode = 1;
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else
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sc->cache_trim_mode = 0;
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/*
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* Prevent the reclaimer from falling into the cache trap: as
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* cache pages start out inactive, every cache fault will tip
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* the scan balance towards the file LRU. And as the file LRU
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* shrinks, so does the window for rotation from references.
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* This means we have a runaway feedback loop where a tiny
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* thrashing file LRU becomes infinitely more attractive than
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* anon pages. Try to detect this based on file LRU size.
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*/
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if (!cgroup_reclaim(sc)) {
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unsigned long total_high_wmark = 0;
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unsigned long free, anon;
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int z;
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free = sum_zone_node_page_state(pgdat->node_id, NR_FREE_PAGES);
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file = node_page_state(pgdat, NR_ACTIVE_FILE) +
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node_page_state(pgdat, NR_INACTIVE_FILE);
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for (z = 0; z < MAX_NR_ZONES; z++) {
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struct zone *zone = &pgdat->node_zones[z];
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if (!managed_zone(zone))
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continue;
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total_high_wmark += high_wmark_pages(zone);
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}
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/*
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* Consider anon: if that's low too, this isn't a
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* runaway file reclaim problem, but rather just
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* extreme pressure. Reclaim as per usual then.
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*/
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anon = node_page_state(pgdat, NR_INACTIVE_ANON);
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sc->file_is_tiny =
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file + free <= total_high_wmark &&
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!(sc->may_deactivate & DEACTIVATE_ANON) &&
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anon >> sc->priority;
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}
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}
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/*
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* Determine how aggressively the anon and file LRU lists should be
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* scanned. The relative value of each set of LRU lists is determined
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@@ -2742,7 +2839,6 @@ static void shrink_node(pg_data_t *pgdat, struct scan_control *sc)
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unsigned long nr_reclaimed, nr_scanned;
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struct lruvec *target_lruvec;
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bool reclaimable = false;
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unsigned long file;
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target_lruvec = mem_cgroup_lruvec(sc->target_mem_cgroup, pgdat);
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@@ -2752,93 +2848,7 @@ again:
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nr_reclaimed = sc->nr_reclaimed;
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nr_scanned = sc->nr_scanned;
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/*
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* Determine the scan balance between anon and file LRUs.
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*/
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spin_lock_irq(&pgdat->lru_lock);
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sc->anon_cost = target_lruvec->anon_cost;
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sc->file_cost = target_lruvec->file_cost;
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spin_unlock_irq(&pgdat->lru_lock);
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/*
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* Target desirable inactive:active list ratios for the anon
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* and file LRU lists.
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*/
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if (!sc->force_deactivate) {
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unsigned long refaults;
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refaults = lruvec_page_state(target_lruvec,
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WORKINGSET_ACTIVATE_ANON);
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if (refaults != target_lruvec->refaults[0] ||
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inactive_is_low(target_lruvec, LRU_INACTIVE_ANON))
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sc->may_deactivate |= DEACTIVATE_ANON;
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else
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sc->may_deactivate &= ~DEACTIVATE_ANON;
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/*
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* When refaults are being observed, it means a new
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* workingset is being established. Deactivate to get
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* rid of any stale active pages quickly.
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*/
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refaults = lruvec_page_state(target_lruvec,
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WORKINGSET_ACTIVATE_FILE);
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if (refaults != target_lruvec->refaults[1] ||
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inactive_is_low(target_lruvec, LRU_INACTIVE_FILE))
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sc->may_deactivate |= DEACTIVATE_FILE;
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else
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sc->may_deactivate &= ~DEACTIVATE_FILE;
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} else
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sc->may_deactivate = DEACTIVATE_ANON | DEACTIVATE_FILE;
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/*
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* If we have plenty of inactive file pages that aren't
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* thrashing, try to reclaim those first before touching
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* anonymous pages.
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*/
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file = lruvec_page_state(target_lruvec, NR_INACTIVE_FILE);
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if (file >> sc->priority && !(sc->may_deactivate & DEACTIVATE_FILE))
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sc->cache_trim_mode = 1;
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else
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sc->cache_trim_mode = 0;
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/*
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* Prevent the reclaimer from falling into the cache trap: as
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* cache pages start out inactive, every cache fault will tip
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* the scan balance towards the file LRU. And as the file LRU
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* shrinks, so does the window for rotation from references.
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* This means we have a runaway feedback loop where a tiny
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* thrashing file LRU becomes infinitely more attractive than
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* anon pages. Try to detect this based on file LRU size.
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*/
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if (!cgroup_reclaim(sc)) {
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unsigned long total_high_wmark = 0;
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unsigned long free, anon;
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int z;
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free = sum_zone_node_page_state(pgdat->node_id, NR_FREE_PAGES);
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file = node_page_state(pgdat, NR_ACTIVE_FILE) +
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node_page_state(pgdat, NR_INACTIVE_FILE);
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for (z = 0; z < MAX_NR_ZONES; z++) {
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struct zone *zone = &pgdat->node_zones[z];
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if (!managed_zone(zone))
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continue;
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total_high_wmark += high_wmark_pages(zone);
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}
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/*
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* Consider anon: if that's low too, this isn't a
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* runaway file reclaim problem, but rather just
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* extreme pressure. Reclaim as per usual then.
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*/
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anon = node_page_state(pgdat, NR_INACTIVE_ANON);
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sc->file_is_tiny =
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file + free <= total_high_wmark &&
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!(sc->may_deactivate & DEACTIVATE_ANON) &&
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anon >> sc->priority;
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}
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prepare_scan_count(pgdat, sc);
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shrink_node_memcgs(pgdat, sc);
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