| Message ID | 20220309021230.721028-4-yuzhao@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Multi-Gen LRU Framework | expand |
On Wed, Mar 9, 2022 at 3:47 PM Yu Zhao <yuzhao@google.com> wrote: > > This patch refactors shrink_node() to improve readability for the > upcoming changes to mm/vmscan.c. > > Signed-off-by: Yu Zhao <yuzhao@google.com> > 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> Reviewed-by: Barry Song <baohua@kernel.org> seems nice refactoring since we are going to skip the whole function for lru_gen later: static void prepare_scan_count(pg_data_t *pgdat, struct scan_control *sc) { unsigned long file; struct lruvec *target_lruvec; if (lru_gen_enabled()) return; ... } > --- > mm/vmscan.c | 198 +++++++++++++++++++++++++++------------------------- > 1 file changed, 104 insertions(+), 94 deletions(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 59b14e0d696c..8e744cdf802f 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -2718,6 +2718,109 @@ enum scan_balance { > SCAN_FILE, > }; > > +static void prepare_scan_count(pg_data_t *pgdat, struct scan_control *sc) > +{ > + unsigned long file; > + struct lruvec *target_lruvec; > + > + target_lruvec = mem_cgroup_lruvec(sc->target_mem_cgroup, pgdat); > + > + /* > + * Flush the memory cgroup stats, so that we read accurate per-memcg > + * lruvec stats for heuristics. > + */ > + mem_cgroup_flush_stats(); > + > + /* > + * Determine the scan balance between anon and file LRUs. > + */ > + spin_lock_irq(&target_lruvec->lru_lock); > + sc->anon_cost = target_lruvec->anon_cost; > + sc->file_cost = target_lruvec->file_cost; > + spin_unlock_irq(&target_lruvec->lru_lock); > + > + /* > + * Target desirable inactive:active list ratios for the anon > + * and file LRU lists. > + */ > + if (!sc->force_deactivate) { > + unsigned long refaults; > + > + refaults = lruvec_page_state(target_lruvec, > + WORKINGSET_ACTIVATE_ANON); > + if (refaults != target_lruvec->refaults[0] || > + inactive_is_low(target_lruvec, LRU_INACTIVE_ANON)) > + sc->may_deactivate |= DEACTIVATE_ANON; > + else > + sc->may_deactivate &= ~DEACTIVATE_ANON; > + > + /* > + * When refaults are being observed, it means a new > + * workingset is being established. Deactivate to get > + * rid of any stale active pages quickly. > + */ > + refaults = lruvec_page_state(target_lruvec, > + WORKINGSET_ACTIVATE_FILE); > + if (refaults != target_lruvec->refaults[1] || > + inactive_is_low(target_lruvec, LRU_INACTIVE_FILE)) > + sc->may_deactivate |= DEACTIVATE_FILE; > + else > + sc->may_deactivate &= ~DEACTIVATE_FILE; > + } else > + sc->may_deactivate = DEACTIVATE_ANON | DEACTIVATE_FILE; > + > + /* > + * If we have plenty of inactive file pages that aren't > + * thrashing, try to reclaim those first before touching > + * anonymous pages. > + */ > + file = lruvec_page_state(target_lruvec, NR_INACTIVE_FILE); > + if (file >> sc->priority && !(sc->may_deactivate & DEACTIVATE_FILE)) > + sc->cache_trim_mode = 1; > + else > + sc->cache_trim_mode = 0; > + > + /* > + * Prevent the reclaimer from falling into the cache trap: as > + * cache pages start out inactive, every cache fault will tip > + * the scan balance towards the file LRU. And as the file LRU > + * shrinks, so does the window for rotation from references. > + * This means we have a runaway feedback loop where a tiny > + * thrashing file LRU becomes infinitely more attractive than > + * anon pages. Try to detect this based on file LRU size. > + */ > + if (!cgroup_reclaim(sc)) { > + unsigned long total_high_wmark = 0; > + unsigned long free, anon; > + int z; > + > + free = sum_zone_node_page_state(pgdat->node_id, NR_FREE_PAGES); > + file = node_page_state(pgdat, NR_ACTIVE_FILE) + > + node_page_state(pgdat, NR_INACTIVE_FILE); > + > + for (z = 0; z < MAX_NR_ZONES; z++) { > + struct zone *zone = &pgdat->node_zones[z]; > + > + if (!managed_zone(zone)) > + continue; > + > + total_high_wmark += high_wmark_pages(zone); > + } > + > + /* > + * Consider anon: if that's low too, this isn't a > + * runaway file reclaim problem, but rather just > + * extreme pressure. Reclaim as per usual then. > + */ > + anon = node_page_state(pgdat, NR_INACTIVE_ANON); > + > + sc->file_is_tiny = > + file + free <= total_high_wmark && > + !(sc->may_deactivate & DEACTIVATE_ANON) && > + anon >> sc->priority; > + } > +} > + > /* > * Determine how aggressively the anon and file LRU lists should be > * scanned. The relative value of each set of LRU lists is determined > @@ -3188,109 +3291,16 @@ static void shrink_node(pg_data_t *pgdat, struct scan_control *sc) > unsigned long nr_reclaimed, nr_scanned; > struct lruvec *target_lruvec; > bool reclaimable = false; > - unsigned long file; > > target_lruvec = mem_cgroup_lruvec(sc->target_mem_cgroup, pgdat); > > again: > - /* > - * Flush the memory cgroup stats, so that we read accurate per-memcg > - * lruvec stats for heuristics. > - */ > - mem_cgroup_flush_stats(); > - > memset(&sc->nr, 0, sizeof(sc->nr)); > > nr_reclaimed = sc->nr_reclaimed; > nr_scanned = sc->nr_scanned; > > - /* > - * Determine the scan balance between anon and file LRUs. > - */ > - spin_lock_irq(&target_lruvec->lru_lock); > - sc->anon_cost = target_lruvec->anon_cost; > - sc->file_cost = target_lruvec->file_cost; > - spin_unlock_irq(&target_lruvec->lru_lock); > - > - /* > - * Target desirable inactive:active list ratios for the anon > - * and file LRU lists. > - */ > - if (!sc->force_deactivate) { > - unsigned long refaults; > - > - refaults = lruvec_page_state(target_lruvec, > - WORKINGSET_ACTIVATE_ANON); > - if (refaults != target_lruvec->refaults[0] || > - inactive_is_low(target_lruvec, LRU_INACTIVE_ANON)) > - sc->may_deactivate |= DEACTIVATE_ANON; > - else > - sc->may_deactivate &= ~DEACTIVATE_ANON; > - > - /* > - * When refaults are being observed, it means a new > - * workingset is being established. Deactivate to get > - * rid of any stale active pages quickly. > - */ > - refaults = lruvec_page_state(target_lruvec, > - WORKINGSET_ACTIVATE_FILE); > - if (refaults != target_lruvec->refaults[1] || > - inactive_is_low(target_lruvec, LRU_INACTIVE_FILE)) > - sc->may_deactivate |= DEACTIVATE_FILE; > - else > - sc->may_deactivate &= ~DEACTIVATE_FILE; > - } else > - sc->may_deactivate = DEACTIVATE_ANON | DEACTIVATE_FILE; > - > - /* > - * If we have plenty of inactive file pages that aren't > - * thrashing, try to reclaim those first before touching > - * anonymous pages. > - */ > - file = lruvec_page_state(target_lruvec, NR_INACTIVE_FILE); > - if (file >> sc->priority && !(sc->may_deactivate & DEACTIVATE_FILE)) > - sc->cache_trim_mode = 1; > - else > - sc->cache_trim_mode = 0; > - > - /* > - * Prevent the reclaimer from falling into the cache trap: as > - * cache pages start out inactive, every cache fault will tip > - * the scan balance towards the file LRU. And as the file LRU > - * shrinks, so does the window for rotation from references. > - * This means we have a runaway feedback loop where a tiny > - * thrashing file LRU becomes infinitely more attractive than > - * anon pages. Try to detect this based on file LRU size. > - */ > - if (!cgroup_reclaim(sc)) { > - unsigned long total_high_wmark = 0; > - unsigned long free, anon; > - int z; > - > - free = sum_zone_node_page_state(pgdat->node_id, NR_FREE_PAGES); > - file = node_page_state(pgdat, NR_ACTIVE_FILE) + > - node_page_state(pgdat, NR_INACTIVE_FILE); > - > - for (z = 0; z < MAX_NR_ZONES; z++) { > - struct zone *zone = &pgdat->node_zones[z]; > - if (!managed_zone(zone)) > - continue; > - > - total_high_wmark += high_wmark_pages(zone); > - } > - > - /* > - * Consider anon: if that's low too, this isn't a > - * runaway file reclaim problem, but rather just > - * extreme pressure. Reclaim as per usual then. > - */ > - anon = node_page_state(pgdat, NR_INACTIVE_ANON); > - > - sc->file_is_tiny = > - file + free <= total_high_wmark && > - !(sc->may_deactivate & DEACTIVATE_ANON) && > - anon >> sc->priority; > - } > + prepare_scan_count(pgdat, sc); > > shrink_node_memcgs(pgdat, sc); > > -- > 2.35.1.616.g0bdcbb4464-goog > Thanks Barry
diff --git a/mm/vmscan.c b/mm/vmscan.c index 59b14e0d696c..8e744cdf802f 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2718,6 +2718,109 @@ enum scan_balance { SCAN_FILE, }; +static void prepare_scan_count(pg_data_t *pgdat, struct scan_control *sc) +{ + unsigned long file; + struct lruvec *target_lruvec; + + target_lruvec = mem_cgroup_lruvec(sc->target_mem_cgroup, pgdat); + + /* + * Flush the memory cgroup stats, so that we read accurate per-memcg + * lruvec stats for heuristics. + */ + mem_cgroup_flush_stats(); + + /* + * Determine the scan balance between anon and file LRUs. + */ + spin_lock_irq(&target_lruvec->lru_lock); + sc->anon_cost = target_lruvec->anon_cost; + sc->file_cost = target_lruvec->file_cost; + spin_unlock_irq(&target_lruvec->lru_lock); + + /* + * Target desirable inactive:active list ratios for the anon + * and file LRU lists. + */ + if (!sc->force_deactivate) { + unsigned long refaults; + + refaults = lruvec_page_state(target_lruvec, + WORKINGSET_ACTIVATE_ANON); + if (refaults != target_lruvec->refaults[0] || + inactive_is_low(target_lruvec, LRU_INACTIVE_ANON)) + sc->may_deactivate |= DEACTIVATE_ANON; + else + sc->may_deactivate &= ~DEACTIVATE_ANON; + + /* + * When refaults are being observed, it means a new + * workingset is being established. Deactivate to get + * rid of any stale active pages quickly. + */ + refaults = lruvec_page_state(target_lruvec, + WORKINGSET_ACTIVATE_FILE); + if (refaults != target_lruvec->refaults[1] || + inactive_is_low(target_lruvec, LRU_INACTIVE_FILE)) + sc->may_deactivate |= DEACTIVATE_FILE; + else + sc->may_deactivate &= ~DEACTIVATE_FILE; + } else + sc->may_deactivate = DEACTIVATE_ANON | DEACTIVATE_FILE; + + /* + * If we have plenty of inactive file pages that aren't + * thrashing, try to reclaim those first before touching + * anonymous pages. + */ + file = lruvec_page_state(target_lruvec, NR_INACTIVE_FILE); + if (file >> sc->priority && !(sc->may_deactivate & DEACTIVATE_FILE)) + sc->cache_trim_mode = 1; + else + sc->cache_trim_mode = 0; + + /* + * Prevent the reclaimer from falling into the cache trap: as + * cache pages start out inactive, every cache fault will tip + * the scan balance towards the file LRU. And as the file LRU + * shrinks, so does the window for rotation from references. + * This means we have a runaway feedback loop where a tiny + * thrashing file LRU becomes infinitely more attractive than + * anon pages. Try to detect this based on file LRU size. + */ + if (!cgroup_reclaim(sc)) { + unsigned long total_high_wmark = 0; + unsigned long free, anon; + int z; + + free = sum_zone_node_page_state(pgdat->node_id, NR_FREE_PAGES); + file = node_page_state(pgdat, NR_ACTIVE_FILE) + + node_page_state(pgdat, NR_INACTIVE_FILE); + + for (z = 0; z < MAX_NR_ZONES; z++) { + struct zone *zone = &pgdat->node_zones[z]; + + if (!managed_zone(zone)) + continue; + + total_high_wmark += high_wmark_pages(zone); + } + + /* + * Consider anon: if that's low too, this isn't a + * runaway file reclaim problem, but rather just + * extreme pressure. Reclaim as per usual then. + */ + anon = node_page_state(pgdat, NR_INACTIVE_ANON); + + sc->file_is_tiny = + file + free <= total_high_wmark && + !(sc->may_deactivate & DEACTIVATE_ANON) && + anon >> sc->priority; + } +} + /* * Determine how aggressively the anon and file LRU lists should be * scanned. The relative value of each set of LRU lists is determined @@ -3188,109 +3291,16 @@ static void shrink_node(pg_data_t *pgdat, struct scan_control *sc) unsigned long nr_reclaimed, nr_scanned; struct lruvec *target_lruvec; bool reclaimable = false; - unsigned long file; target_lruvec = mem_cgroup_lruvec(sc->target_mem_cgroup, pgdat); again: - /* - * Flush the memory cgroup stats, so that we read accurate per-memcg - * lruvec stats for heuristics. - */ - mem_cgroup_flush_stats(); - memset(&sc->nr, 0, sizeof(sc->nr)); nr_reclaimed = sc->nr_reclaimed; nr_scanned = sc->nr_scanned; - /* - * Determine the scan balance between anon and file LRUs. - */ - spin_lock_irq(&target_lruvec->lru_lock); - sc->anon_cost = target_lruvec->anon_cost; - sc->file_cost = target_lruvec->file_cost; - spin_unlock_irq(&target_lruvec->lru_lock); - - /* - * Target desirable inactive:active list ratios for the anon - * and file LRU lists. - */ - if (!sc->force_deactivate) { - unsigned long refaults; - - refaults = lruvec_page_state(target_lruvec, - WORKINGSET_ACTIVATE_ANON); - if (refaults != target_lruvec->refaults[0] || - inactive_is_low(target_lruvec, LRU_INACTIVE_ANON)) - sc->may_deactivate |= DEACTIVATE_ANON; - else - sc->may_deactivate &= ~DEACTIVATE_ANON; - - /* - * When refaults are being observed, it means a new - * workingset is being established. Deactivate to get - * rid of any stale active pages quickly. - */ - refaults = lruvec_page_state(target_lruvec, - WORKINGSET_ACTIVATE_FILE); - if (refaults != target_lruvec->refaults[1] || - inactive_is_low(target_lruvec, LRU_INACTIVE_FILE)) - sc->may_deactivate |= DEACTIVATE_FILE; - else - sc->may_deactivate &= ~DEACTIVATE_FILE; - } else - sc->may_deactivate = DEACTIVATE_ANON | DEACTIVATE_FILE; - - /* - * If we have plenty of inactive file pages that aren't - * thrashing, try to reclaim those first before touching - * anonymous pages. - */ - file = lruvec_page_state(target_lruvec, NR_INACTIVE_FILE); - if (file >> sc->priority && !(sc->may_deactivate & DEACTIVATE_FILE)) - sc->cache_trim_mode = 1; - else - sc->cache_trim_mode = 0; - - /* - * Prevent the reclaimer from falling into the cache trap: as - * cache pages start out inactive, every cache fault will tip - * the scan balance towards the file LRU. And as the file LRU - * shrinks, so does the window for rotation from references. - * This means we have a runaway feedback loop where a tiny - * thrashing file LRU becomes infinitely more attractive than - * anon pages. Try to detect this based on file LRU size. - */ - if (!cgroup_reclaim(sc)) { - unsigned long total_high_wmark = 0; - unsigned long free, anon; - int z; - - free = sum_zone_node_page_state(pgdat->node_id, NR_FREE_PAGES); - file = node_page_state(pgdat, NR_ACTIVE_FILE) + - node_page_state(pgdat, NR_INACTIVE_FILE); - - for (z = 0; z < MAX_NR_ZONES; z++) { - struct zone *zone = &pgdat->node_zones[z]; - if (!managed_zone(zone)) - continue; - - total_high_wmark += high_wmark_pages(zone); - } - - /* - * Consider anon: if that's low too, this isn't a - * runaway file reclaim problem, but rather just - * extreme pressure. Reclaim as per usual then. - */ - anon = node_page_state(pgdat, NR_INACTIVE_ANON); - - sc->file_is_tiny = - file + free <= total_high_wmark && - !(sc->may_deactivate & DEACTIVATE_ANON) && - anon >> sc->priority; - } + prepare_scan_count(pgdat, sc); shrink_node_memcgs(pgdat, sc);