netdev - [PATCH v3 08/30] rhashtable: add schedule points

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Date:   Thu, 13 Sep 2018 07:58:40 -0700
From:   Stephen Hemminger <stephen@...workplumber.org>
To:     davem@...emloft.net, gregkh@...uxfoundation.org
Cc:     netdev@...r.kernel.org, stable@...r.kernel.org, edumazet@...gle.com
Subject: [PATCH v3 08/30] rhashtable: add schedule points

From: Eric Dumazet <edumazet@...gle.com>

Rehashing and destroying large hash table takes a lot of time,
and happens in process context. It is safe to add cond_resched()
in rhashtable_rehash_table() and rhashtable_free_and_destroy()

Signed-off-by: Eric Dumazet <edumazet@...gle.com>
Acked-by: Herbert Xu <herbert@...dor.apana.org.au>
Signed-off-by: David S. Miller <davem@...emloft.net>
(cherry picked from commit ae6da1f503abb5a5081f9f6c4a6881de97830f3e)
---
 lib/rhashtable.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index 39215c724fc7..cebbcec877d7 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -364,6 +364,7 @@ static int rhashtable_rehash_table(struct rhashtable *ht)
 		err = rhashtable_rehash_chain(ht, old_hash);
 		if (err)
 			return err;
+		cond_resched();
 	}
 
 	/* Publish the new table pointer. */
@@ -1073,6 +1074,7 @@ void rhashtable_free_and_destroy(struct rhashtable *ht,
 		for (i = 0; i < tbl->size; i++) {
 			struct rhash_head *pos, *next;
 
+			cond_resched();
 			for (pos = rht_dereference(*rht_bucket(tbl, i), ht),
 			     next = !rht_is_a_nulls(pos) ?
 					rht_dereference(pos->next, ht) : NULL;
-- 
2.18.0