diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index eb3815fc94ad..8881198e85c6 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -1536,6 +1536,8 @@ static inline unsigned long pgdat_end_pfn(pg_data_t *pgdat) void build_all_zonelists(pg_data_t *pgdat); void wakeup_kswapd(struct zone *zone, gfp_t gfp_mask, int order, enum zone_type highest_zoneidx); +void kswapd_try_clear_hopeless(struct pglist_data *pgdat, + unsigned int order, int highest_zoneidx); bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark, int highest_zoneidx, unsigned int alloc_flags, long free_pages); diff --git a/mm/vmscan.c b/mm/vmscan.c index b33039000d6e..5d9b1bce6f01 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -5065,7 +5065,7 @@ static void lru_gen_shrink_node(struct pglist_data *pgdat, struct scan_control * blk_finish_plug(&plug); done: if (sc->nr_reclaimed > reclaimed) - atomic_set(&pgdat->kswapd_failures, 0); + kswapd_try_clear_hopeless(pgdat, sc->order, sc->reclaim_idx); } /****************************************************************************** @@ -6132,7 +6132,7 @@ static void shrink_node(pg_data_t *pgdat, struct scan_control *sc) * successful direct reclaim run will revive a dormant kswapd. */ if (reclaimable) - atomic_set(&pgdat->kswapd_failures, 0); + kswapd_try_clear_hopeless(pgdat, sc->order, sc->reclaim_idx); else if (sc->cache_trim_mode) sc->cache_trim_mode_failed = 1; } @@ -7391,6 +7391,24 @@ void wakeup_kswapd(struct zone *zone, gfp_t gfp_flags, int order, wake_up_interruptible(&pgdat->kswapd_wait); } +static void kswapd_clear_hopeless(pg_data_t *pgdat) +{ + atomic_set(&pgdat->kswapd_failures, 0); +} + +/* + * Reset kswapd_failures only when the node is balanced. Without this + * check, successful direct reclaim (e.g., from cgroup memory.high + * throttling) can keep resetting kswapd_failures even when the node + * cannot be balanced, causing kswapd to run endlessly. + */ +void kswapd_try_clear_hopeless(struct pglist_data *pgdat, + unsigned int order, int highest_zoneidx) +{ + if (pgdat_balanced(pgdat, order, highest_zoneidx)) + kswapd_clear_hopeless(pgdat); +} + #ifdef CONFIG_HIBERNATION /* * Try to free `nr_to_reclaim' of memory, system-wide, and return the number of