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Tsirkin" To: David Miller Cc: weiwan@google.com, netdev@vger.kernel.org, kuba@kernel.org, willemb@google.com, virtualization@lists.linux-foundation.org Subject: Re: [PATCH net] virtio-net: suppress bad irq warning for tx napi Message-ID: <20210413002340-mutt-send-email-mst@kernel.org> References: <20210129002136.70865-1-weiwan@google.com> <20210412180353-mutt-send-email-mst@kernel.org> <20210412183141-mutt-send-email-mst@kernel.org> <20210412.161458.652699519749470159.davem@davemloft.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210412.161458.652699519749470159.davem@davemloft.net> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, Apr 12, 2021 at 04:14:58PM -0700, David Miller wrote: > From: "Michael S. Tsirkin" > Date: Mon, 12 Apr 2021 18:33:45 -0400 > > > On Mon, Apr 12, 2021 at 06:08:21PM -0400, Michael S. Tsirkin wrote: > >> OK I started looking at this again. My idea is simple. > >> A. disable callbacks before we try to drain skbs > >> B. actually do disable callbacks even with event idx > >> > >> To make B not regress, we need to > >> C. detect the common case of disable after event triggering and skip the write then. > >> > >> I added a new event_triggered flag for that. > >> Completely untested - but then I could not see the warnings either. > >> Would be very much interested to know whether this patch helps > >> resolve the sruprious interrupt problem at all ... > >> > >> > >> Signed-off-by: Michael S. Tsirkin > > > > Hmm a slightly cleaner alternative is to clear the flag when enabling interrupts ... > > I wonder which cacheline it's best to use for this. > > > > Signed-off-by: Michael S. Tsirkin > > Please make a fresh new submission if you want to use this approach, thanks. Absolutely. This is untested so I just sent this idea out for early feedback and hopefully help with testing on real hardware. Sorry about being unclear. -- MST