On 6 Dec 2019, at 14:55, William Tu wrote:
On Thu, Dec 5, 2019 at 5:43 AM William Tu <[email protected]> wrote:
On Wed, Dec 4, 2019 at 10:06 PM William Tu <[email protected]>
wrote:
The patch works around an error when reconfigure the netdev-afxdp
device into different modes. Currently, when OVS destroy xsk, the
xsk_destruct() in linux kernel calls xdp_put_umem() and defers
calling xdp_umem_release_deferred().
This creates an -EBUSY error when xsk_socket__create() calls
xsk_bind()
xdp_umem_assign_dev()
xdp_get_umem_from_qid()
And this is because xdp_clear_umem_at_qid() is deferred so not
clearing umem yet. The issue can be reproduced by just changing
xdp-mode multiple times, ex:
ovs-vsctl -- set interface afxdp-p0 \
options:n_rxq=1 type="afxdp" options:xdp-mode=best-effort
ovs-vsctl -- set interface afxdp-p0 \
options:n_rxq=1 type="afxdp" options:xdp-mode=generic
The patch fixes it by adding a delay, hopefully the umem has
been properly cleanup.
Signed-off-by: William Tu <[email protected]>
---
lib/netdev-afxdp.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/lib/netdev-afxdp.c b/lib/netdev-afxdp.c
index ca2dfd005b9f..84897f1fd025 100644
--- a/lib/netdev-afxdp.c
+++ b/lib/netdev-afxdp.c
@@ -661,6 +661,9 @@ netdev_afxdp_reconfigure(struct netdev *netdev)
struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
int err = 0;
+ /* Time for umem to be released in kernel. */
+ xnanosleep(500000);
+
ovs_mutex_lock(&dev->mutex);
if (netdev->n_rxq == dev->requested_n_rxq
--
2.7.4
Now I think it's a bad solution. Let me work on other way
to fix it.
This is an issue due to XSK async cleanup.
We can wait for fix later.
https://lore.kernel.org/netdev/caldo+sbciany5erev5yhvciosjmdmrpbqdf6xbhxfbf6gvp...@mail.gmail.com/T/#m10cd49235090496dab98c24837dd1a2fbcb2e187
Waiting for the sync cleanup might make sense. Adding a xnanosleep()
delay is not the way forward.
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