From: Jesse Brandeburg <jesse.brandeburg@intel.com> To: intel-wired-lan@lists.osuosl.org Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>, netdev@vger.kernel.org, Oleksandr Natalenko <oleksandr@natalenko.name>, Danielle Ratson <danieller@nvidia.com>, Alexander Duyck <alexander.duyck@gmail.com> Subject: [PATCH net v2] igb: fix netpoll exit with traffic Date: Tue, 23 Nov 2021 12:40:00 -0800 [thread overview] Message-ID: <20211123204000.1597971-1-jesse.brandeburg@intel.com> (raw) Oleksandr brought a bug report where netpoll causes trace messages in the log on igb. Danielle brought this back up as still occuring, so we'll try again. [22038.710800] ------------[ cut here ]------------ [22038.710801] igb_poll+0x0/0x1440 [igb] exceeded budget in poll [22038.710802] WARNING: CPU: 12 PID: 40362 at net/core/netpoll.c:155 netpoll_poll_dev+0x18a/0x1a0 As Alex suggested, change the driver to return work_done at the exit of napi_poll, which should be safe to do in this driver because it is not polling multiple queues in this single napi context (multiple queues attached to one MSI-X vector). Several other drivers contain the same simple sequence, so I hope this will not create new problems. Fixes: 16eb8815c235 ("igb: Refactor clean_rx_irq to reduce overhead and improve performance") Reported-by: Oleksandr Natalenko <oleksandr@natalenko.name> Reported-by: Danielle Ratson <danieller@nvidia.com> Suggested-by: Alexander Duyck <alexander.duyck@gmail.com> Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com> --- COMPILE TESTED ONLY! I have no way to reproduce this even on a machine I have with igb. It works fine to load the igb driver and netconsole with no errors. --- v2: simplified patch with an attempt to make it work v1: original patch that apparently didn't work --- drivers/net/ethernet/intel/igb/igb_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index e647cc89c239..5e24b7ce5a92 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -8104,7 +8104,7 @@ static int igb_poll(struct napi_struct *napi, int budget) if (likely(napi_complete_done(napi, work_done))) igb_ring_irq_enable(q_vector); - return min(work_done, budget - 1); + return work_done; } /** -- 2.33.1
WARNING: multiple messages have this Message-ID (diff)
From: Jesse Brandeburg <jesse.brandeburg@intel.com> To: intel-wired-lan@osuosl.org Subject: [Intel-wired-lan] [PATCH net v2] igb: fix netpoll exit with traffic Date: Tue, 23 Nov 2021 12:40:00 -0800 [thread overview] Message-ID: <20211123204000.1597971-1-jesse.brandeburg@intel.com> (raw) Oleksandr brought a bug report where netpoll causes trace messages in the log on igb. Danielle brought this back up as still occuring, so we'll try again. [22038.710800] ------------[ cut here ]------------ [22038.710801] igb_poll+0x0/0x1440 [igb] exceeded budget in poll [22038.710802] WARNING: CPU: 12 PID: 40362 at net/core/netpoll.c:155 netpoll_poll_dev+0x18a/0x1a0 As Alex suggested, change the driver to return work_done at the exit of napi_poll, which should be safe to do in this driver because it is not polling multiple queues in this single napi context (multiple queues attached to one MSI-X vector). Several other drivers contain the same simple sequence, so I hope this will not create new problems. Fixes: 16eb8815c235 ("igb: Refactor clean_rx_irq to reduce overhead and improve performance") Reported-by: Oleksandr Natalenko <oleksandr@natalenko.name> Reported-by: Danielle Ratson <danieller@nvidia.com> Suggested-by: Alexander Duyck <alexander.duyck@gmail.com> Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com> --- COMPILE TESTED ONLY! I have no way to reproduce this even on a machine I have with igb. It works fine to load the igb driver and netconsole with no errors. --- v2: simplified patch with an attempt to make it work v1: original patch that apparently didn't work --- drivers/net/ethernet/intel/igb/igb_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index e647cc89c239..5e24b7ce5a92 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -8104,7 +8104,7 @@ static int igb_poll(struct napi_struct *napi, int budget) if (likely(napi_complete_done(napi, work_done))) igb_ring_irq_enable(q_vector); - return min(work_done, budget - 1); + return work_done; } /** -- 2.33.1
next reply other threads:[~2021-11-23 20:40 UTC|newest] Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-11-23 20:40 Jesse Brandeburg [this message] 2021-11-23 20:40 ` [Intel-wired-lan] [PATCH net v2] igb: fix netpoll exit with traffic Jesse Brandeburg 2021-11-24 7:51 ` Danielle Ratson 2021-11-24 7:51 ` [Intel-wired-lan] " Danielle Ratson 2021-11-24 8:03 ` Danielle Ratson 2021-11-24 8:03 ` [Intel-wired-lan] " Danielle Ratson 2021-11-24 22:32 ` Kris Karas (Bug reporting) 2021-11-24 22:32 ` [Intel-wired-lan] " Kris Karas 2021-11-25 7:03 ` Oleksandr Natalenko 2021-11-25 7:03 ` [Intel-wired-lan] " Oleksandr Natalenko 2021-11-25 7:37 ` Danielle Ratson 2021-11-25 7:37 ` [Intel-wired-lan] " Danielle Ratson 2021-11-25 8:01 ` Danielle Ratson 2021-11-25 8:01 ` [Intel-wired-lan] " Danielle Ratson 2021-11-25 15:50 ` patchwork-bot+netdevbpf 2021-11-25 15:50 ` [Intel-wired-lan] " patchwork-bot+netdevbpf
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