X-Git-Url: https://git.stricted.de/?a=blobdiff_plain;f=mm%2Fvmscan.c;h=a1e3becef05e11ddaa39655e872ae88d8ee23417;hb=6d2eb0f1168c709a7c8fd62f2c90f6643e39609c;hp=fa6a85378ee41400985aca748cd76b59c0f87594;hpb=aad760136537fdfa10e5ac76bd3c79bde2100863;p=GitHub%2Fmt8127%2Fandroid_kernel_alcatel_ttab.git diff --git a/mm/vmscan.c b/mm/vmscan.c index fa6a85378ee4..a1e3becef05e 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -48,6 +48,7 @@ #include #include +#include #include "internal.h" @@ -729,20 +730,15 @@ static unsigned long shrink_page_list(struct list_head *page_list, * could easily OOM just because too many pages are in * writeback and there is nothing else to reclaim. * - * Check __GFP_IO, certainly because a loop driver + * Require may_enter_fs to wait on writeback, because + * fs may not have submitted IO yet. And a loop driver * thread might enter reclaim, and deadlock if it waits * on a page for which it is needed to do the write * (loop masks off __GFP_IO|__GFP_FS for this reason); * but more thought would probably show more reasons. - * - * Don't require __GFP_FS, since we're not going into - * the FS, just waiting on its writeback completion. - * Worryingly, ext4 gfs2 and xfs allocate pages with - * grab_cache_page_write_begin(,,AOP_FLAG_NOFS), so - * testing may_enter_fs here is liable to OOM on them. */ if (global_reclaim(sc) || - !PageReclaim(page) || !(sc->gfp_mask & __GFP_IO)) { + !PageReclaim(page) || !may_enter_fs) { /* * This is slightly racy - end_page_writeback() * might have just cleared PageReclaim, then @@ -929,7 +925,7 @@ cull_mlocked: if (PageSwapCache(page)) try_to_free_swap(page); unlock_page(page); - putback_lru_page(page); + list_add(&page->lru, &ret_pages); continue; activate_locked: @@ -978,7 +974,8 @@ unsigned long reclaim_clean_pages_from_list(struct zone *zone, LIST_HEAD(clean_pages); list_for_each_entry_safe(page, next, page_list, lru) { - if (page_is_file_cache(page) && !PageDirty(page)) { + if (page_is_file_cache(page) && !PageDirty(page) && + !isolated_balloon_page(page)) { ClearPageActive(page); list_move(&page->lru, &clean_pages); } @@ -2115,6 +2112,20 @@ static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc) return aborted_reclaim; } +static unsigned long zone_reclaimable_pages(struct zone *zone) +{ + int nr; + + nr = zone_page_state(zone, NR_ACTIVE_FILE) + + zone_page_state(zone, NR_INACTIVE_FILE); + + if (get_nr_swap_pages() > 0) + nr += zone_page_state(zone, NR_ACTIVE_ANON) + + zone_page_state(zone, NR_INACTIVE_ANON); + + return nr; +} + static bool zone_reclaimable(struct zone *zone) { return zone->pages_scanned < zone_reclaimable_pages(zone) * 6; @@ -2270,10 +2281,17 @@ static bool pfmemalloc_watermark_ok(pg_data_t *pgdat) for (i = 0; i <= ZONE_NORMAL; i++) { zone = &pgdat->node_zones[i]; + if (!populated_zone(zone)) + continue; + pfmemalloc_reserve += min_wmark_pages(zone); free_pages += zone_page_state(zone, NR_FREE_PAGES); } + /* If there are no reserves (unexpected config) then do not throttle */ + if (!pfmemalloc_reserve) + return true; + wmark_ok = free_pages > pfmemalloc_reserve / 2; /* kswapd must be awake if processes are being throttled */ @@ -2298,9 +2316,9 @@ static bool pfmemalloc_watermark_ok(pg_data_t *pgdat) static bool throttle_direct_reclaim(gfp_t gfp_mask, struct zonelist *zonelist, nodemask_t *nodemask) { + struct zoneref *z; struct zone *zone; - int high_zoneidx = gfp_zone(gfp_mask); - pg_data_t *pgdat; + pg_data_t *pgdat = NULL; /* * Kernel threads should not be throttled as they may be indirectly @@ -2319,10 +2337,34 @@ static bool throttle_direct_reclaim(gfp_t gfp_mask, struct zonelist *zonelist, if (fatal_signal_pending(current)) goto out; - /* Check if the pfmemalloc reserves are ok */ - first_zones_zonelist(zonelist, high_zoneidx, NULL, &zone); - pgdat = zone->zone_pgdat; - if (pfmemalloc_watermark_ok(pgdat)) + /* + * Check if the pfmemalloc reserves are ok by finding the first node + * with a usable ZONE_NORMAL or lower zone. The expectation is that + * GFP_KERNEL will be required for allocating network buffers when + * swapping over the network so ZONE_HIGHMEM is unusable. + * + * Throttling is based on the first usable node and throttled processes + * wait on a queue until kswapd makes progress and wakes them. There + * is an affinity then between processes waking up and where reclaim + * progress has been made assuming the process wakes on the same node. + * More importantly, processes running on remote nodes will not compete + * for remote pfmemalloc reserves and processes on different nodes + * should make reasonable progress. + */ + for_each_zone_zonelist_nodemask(zone, z, zonelist, + gfp_mask, nodemask) { + if (zone_idx(zone) > ZONE_NORMAL) + continue; + + /* Throttle based on the first usable node */ + pgdat = zone->zone_pgdat; + if (pfmemalloc_watermark_ok(pgdat)) + goto out; + break; + } + + /* If no zone was usable by the allocation flags then do not throttle */ + if (!pgdat) goto out; /* Account for the throttling */ @@ -2584,18 +2626,20 @@ static bool prepare_kswapd_sleep(pg_data_t *pgdat, int order, long remaining, return false; /* - * There is a potential race between when kswapd checks its watermarks - * and a process gets throttled. There is also a potential race if - * processes get throttled, kswapd wakes, a large process exits therby - * balancing the zones that causes kswapd to miss a wakeup. If kswapd - * is going to sleep, no process should be sleeping on pfmemalloc_wait - * so wake them now if necessary. If necessary, processes will wake - * kswapd and get throttled again + * The throttled processes are normally woken up in balance_pgdat() as + * soon as pfmemalloc_watermark_ok() is true. But there is a potential + * race between when kswapd checks the watermarks and a process gets + * throttled. There is also a potential race if processes get + * throttled, kswapd wakes, a large process exits thereby balancing the + * zones, which causes kswapd to exit balance_pgdat() before reaching + * the wake up checks. If kswapd is going to sleep, no process should + * be sleeping on pfmemalloc_wait, so wake them now if necessary. If + * the wake up is premature, processes will wake kswapd and get + * throttled again. The difference from wake ups in balance_pgdat() is + * that here we are under prepare_to_wait(). */ - if (waitqueue_active(&pgdat->pfmemalloc_wait)) { - wake_up(&pgdat->pfmemalloc_wait); - return false; - } + if (waitqueue_active(&pgdat->pfmemalloc_wait)) + wake_up_all(&pgdat->pfmemalloc_wait); return pgdat_balanced(pgdat, order, classzone_idx); } @@ -3043,7 +3087,10 @@ static int kswapd(void *p) } } + tsk->flags &= ~(PF_MEMALLOC | PF_SWAPWRITE | PF_KSWAPD); current->reclaim_state = NULL; + lockdep_clear_current_reclaim_state(); + return 0; } @@ -3073,41 +3120,6 @@ void wakeup_kswapd(struct zone *zone, int order, enum zone_type classzone_idx) wake_up_interruptible(&pgdat->kswapd_wait); } -/* - * The reclaimable count would be mostly accurate. - * The less reclaimable pages may be - * - mlocked pages, which will be moved to unevictable list when encountered - * - mapped pages, which may require several travels to be reclaimed - * - dirty pages, which is not "instantly" reclaimable - */ -unsigned long global_reclaimable_pages(void) -{ - int nr; - - nr = global_page_state(NR_ACTIVE_FILE) + - global_page_state(NR_INACTIVE_FILE); - - if (get_nr_swap_pages() > 0) - nr += global_page_state(NR_ACTIVE_ANON) + - global_page_state(NR_INACTIVE_ANON); - - return nr; -} - -unsigned long zone_reclaimable_pages(struct zone *zone) -{ - int nr; - - nr = zone_page_state(zone, NR_ACTIVE_FILE) + - zone_page_state(zone, NR_INACTIVE_FILE); - - if (get_nr_swap_pages() > 0) - nr += zone_page_state(zone, NR_ACTIVE_ANON) + - zone_page_state(zone, NR_INACTIVE_ANON); - - return nr; -} - #ifdef CONFIG_HIBERNATION /* * Try to free `nr_to_reclaim' of memory, system-wide, and return the number of