From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Kirsher Date: Thu, 20 Sep 2018 14:01:37 -0700 Subject: [Intel-wired-lan] [PATCH net] ixgbe: check return value of napi_complete_done() In-Reply-To: References: <20180920190113.490005-1-songliubraving@fb.com> Message-ID: <2ca0e823642d232092017f66e8151652e22e74a1.camel@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: intel-wired-lan@osuosl.org List-ID: On Thu, 2018-09-20 at 13:35 -0700, Eric Dumazet wrote: > On 09/20/2018 12:01 PM, Song Liu wrote: > > The NIC driver should only enable interrupts when napi_complete_done() > > returns true. This patch adds the check for ixgbe. > > > > Cc: stable at vger.kernel.org # 4.10+ > > Cc: Jeff Kirsher > > Suggested-by: Eric Dumazet > > Signed-off-by: Song Liu > > --- > > > Well, unfortunately we do not know why this is needed, > this is why I have not yet sent this patch formally. > > netpoll has correct synchronization : > > poll_napi() places into napi->poll_owner current cpu number before > calling poll_one_napi() > > netpoll_poll_lock() does also use napi->poll_owner > > When netpoll calls ixgbe poll() method, it passed a budget of 0, > meaning napi_complete_done() is not called. > > As long as we can not explain the problem properly in the changelog, > we should investigate, otherwise we will probably see coming dozens of > patches > trying to fix a 'potential hazard'. Agreed, which is why I have our validation and developers looking into it, while we test the current patch from Song. -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 833 bytes Desc: This is a digitally signed message part URL: