From 5beb5c90c1f54d745da040aa05634a5830ba4a4c Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 26 Feb 2015 07:20:34 -0800 Subject: [PATCH] rhashtable: use cond_resched() If a hash table has 128 slots and 16384 elems, expand to 256 slots takes more than one second. For larger sets, a soft lockup is detected. Holding cpu for that long, even in a work queue is a show stopper for non preemptable kernels. cond_resched() at strategic points to allow process scheduler to reschedule us. Signed-off-by: Eric Dumazet Acked-by: Daniel Borkmann Signed-off-by: David S. Miller --- lib/rhashtable.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/lib/rhashtable.c b/lib/rhashtable.c index 090641db4c0d..b5344ef4c684 100644 --- a/lib/rhashtable.c +++ b/lib/rhashtable.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include #include @@ -412,6 +413,7 @@ int rhashtable_expand(struct rhashtable *ht) } } unlock_buckets(new_tbl, old_tbl, new_hash); + cond_resched(); } /* Unzip interleaved hash chains */ @@ -435,6 +437,7 @@ int rhashtable_expand(struct rhashtable *ht) complete = false; unlock_buckets(new_tbl, old_tbl, old_hash); + cond_resched(); } } @@ -493,6 +496,7 @@ int rhashtable_shrink(struct rhashtable *ht) tbl->buckets[new_hash + new_tbl->size]); unlock_buckets(new_tbl, tbl, new_hash); + cond_resched(); } /* Publish the new, valid hash table */ -- 2.20.1