On 3/5/25 09:58, Vlastimil Babka wrote:
On 3/5/25 09:20, Hannes Reinecke wrote:
On 3/4/25 20:44, Vlastimil Babka wrote:
On 3/4/25 20:39, Hannes Reinecke wrote:
[ .. ]
Good news and bad news ...
Good news: TLS works again!
Bad news: no errors.
Wait, did you add a WARN_ON_ONCE() to the put_page() as I suggested? If yes
and there was no error, it would have to be leaking the page. Or the path
uses folio_put() and we'd need to put the warning there.
That triggers:
...
Not surprisingly, though, as the original code did a get_page(), so
there had to be a corresponding put_page() somewhere.
Is is this one? If there's no more warning afterwards, that should be it.
diff --git a/net/core/skmsg.c b/net/core/skmsg.c
index 61f3f3d4e528..b37d99cec069 100644
--- a/net/core/skmsg.c
+++ b/net/core/skmsg.c
@@ -182,9 +182,14 @@ static int sk_msg_free_elem(struct sock *sk, struct sk_msg *msg, u32 i,
/* When the skb owns the memory we free it from consume_skb path. */
if (!msg->skb) {
+ struct folio *folio;
+
if (charge)
sk_mem_uncharge(sk, len);
- put_page(sg_page(sge));
+
+ folio = page_folio(sg_page(sge));
+ if (!folio_test_slab(folio))
+ folio_put(folio);
}
memset(sge, 0, sizeof(*sge));
return len;
Oh, sure. But what annoys me: why do we have to care?
When doing I/O _all_ data is stuffed into bvecs via
bio_add_page(), and after that information about the
origin is lost; any iteration on the bio will be a bvec
iteration.
Previously we could just do a bvec iteration, get a reference
for each page, and start processing.
Now suddenly the caller has to check if it's a slab page and don't
get a reference for that. Not only that, he also has to remember
to _not_ drop the reference when he's done.
And, of course, tracing get_page() and the corresponding put_page()
calls through all the layers.
Really?
Cheers,
Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
hare@xxxxxxx +49 911 74053 688
SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg
HRB 36809 (AG Nürnberg), GF: I. Totev, A. McDonald, W. Knoblich
