On Wed, 23 Oct 2024 16:13:36 +0200 Matthieu Baerts wrote:
On 23/10/2024 14:21, Simon Horman wrote:
On Mon, Oct 21, 2024 at 12:25:27PM +0200, Matthieu Baerts (NGI0) wrote:
mptcp_get_available_schedulers() needs to iterate over the schedulers' list only to read the names: it doesn't modify anything there.
In this case, it is enough to hold the RCU read lock, no need to combine this with the associated spin lock.
Fixes: 73c900aa3660 ("mptcp: add net.mptcp.available_schedulers") Cc: stable@vger.kernel.org Suggested-by: Paolo Abeni pabeni@redhat.com Reviewed-by: Geliang Tang geliang@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org
I do wonder if it would be more appropriate to route this via net-next (without a fixes tag) rather than via net. But either way this looks good to me.
Good point. On one hand, I marked it as a fix, because when working on the patch 1/3, we noticed these spin_(un)lock() were not supposed to be there in the first place. On the other hand, even it's fixing a small performance issue, it is not fixing a regression.
I think it is easier to route this via -net, but I'm fine if it is applied in net-next.
I agree with Simon's initial response. Let's not blur the lines. Please re-queue for net-next, I'll apply the rest.
BTW thanks a lot for proactively fixing the CONFIG_PROVE_RCU_LIST splats!