page_pool: store detach_time as ktime_t to avoid false-negatives

While testing other changes in vng I noticed that
nl_netdev.page_pool_check flakes. This never happens in real CI.

Turns out vng may boot and get to that test in less than a second.
page_pool_detached() records the detach time in seconds, so if
vng is fast enough detach time is set to 0. Other code treats
0 as "not detached". detach_time is only used to report the state
to the user, so it's not a huge deal in practice but let's fix it.
Store the raw ktime_t (nanoseconds) instead. A nanosecond value
of 0 is practically impossible.

Acked-by: Jesper Dangaard Brouer <hawk@kernel.org>
Fixes: 69cb4952b6f6 ("net: page_pool: report when page pool was destroyed")
Link: https://patch.msgid.link/20260310003907.3540019-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/include/net/page_pool/types.h b/include/net/page_pool/types.h
index 0d453484a585fb31274a10841480be5ac5388f23..cdd95477af7a20ee895005fdec948b5804501360 100644 (file)
--- a/include/net/page_pool/types.h
+++ b/include/net/page_pool/types.h
@@ -247,7 +247,7 @@ struct page_pool {
        /* User-facing fields, protected by page_pools_lock */
        struct {
                struct hlist_node list;
-               u64 detach_time;
+               ktime_t detach_time;
                u32 id;
        } user;
 };

diff --git a/net/core/page_pool_user.c b/net/core/page_pool_user.c
index c82a95beceff84e9ec5fcbae957f897368044829..ee5060d8eec0eb7bab7c2262933de0d6fd19bd34 100644 (file)
--- a/net/core/page_pool_user.c
+++ b/net/core/page_pool_user.c
@@ -245,7 +245,7 @@ page_pool_nl_fill(struct sk_buff *rsp, const struct page_pool *pool,
                goto err_cancel;
        if (pool->user.detach_time &&
            nla_put_uint(rsp, NETDEV_A_PAGE_POOL_DETACH_TIME,
-                        pool->user.detach_time))
+                        ktime_divns(pool->user.detach_time, NSEC_PER_SEC)))
                goto err_cancel;
 
        if (pool->mp_ops && pool->mp_ops->nl_fill(pool->mp_priv, rsp, NULL))
@@ -337,7 +337,7 @@ err_unlock:
 void page_pool_detached(struct page_pool *pool)
 {
        mutex_lock(&page_pools_lock);
-       pool->user.detach_time = ktime_get_boottime_seconds();
+       pool->user.detach_time = ktime_get_boottime();
        netdev_nl_page_pool_event(pool, NETDEV_CMD_PAGE_POOL_CHANGE_NTF);
        mutex_unlock(&page_pools_lock);
 }