From: Daniel Machon Date: Thu, 5 Dec 2024 13:54:26 +0000 (+0100) Subject: net: sparx5: fix FDMA performance issue X-Git-Tag: v6.13-rc3~36^2~28^2~2 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=f004f2e535e2b66ccbf5ac35f8eaadeac70ad7b7;p=thirdparty%2Fkernel%2Flinux.git net: sparx5: fix FDMA performance issue The FDMA handler is responsible for scheduling a NAPI poll, which will eventually fetch RX packets from the FDMA queue. Currently, the FDMA handler is run in a threaded context. For some reason, this kills performance. Admittedly, I did not do a thorough investigation to see exactly what causes the issue, however, I noticed that in the other driver utilizing the same FDMA engine, we run the FDMA handler in hard IRQ context. Fix this performance issue, by running the FDMA handler in hard IRQ context, not deferring any work to a thread. Prior to this change, the RX UDP performance was: Interval Transfer Bitrate Jitter 0.00-10.20 sec 44.6 MBytes 36.7 Mbits/sec 0.027 ms After this change, the rx UDP performance is: Interval Transfer Bitrate Jitter 0.00-9.12 sec 1.01 GBytes 953 Mbits/sec 0.020 ms Fixes: 10615907e9b5 ("net: sparx5: switchdev: adding frame DMA functionality") Signed-off-by: Daniel Machon Signed-off-by: David S. Miller --- diff --git a/drivers/net/ethernet/microchip/sparx5/sparx5_main.c b/drivers/net/ethernet/microchip/sparx5/sparx5_main.c index 2b58fcb9422e9..f61aa15beab7c 100644 --- a/drivers/net/ethernet/microchip/sparx5/sparx5_main.c +++ b/drivers/net/ethernet/microchip/sparx5/sparx5_main.c @@ -780,12 +780,11 @@ static int sparx5_start(struct sparx5 *sparx5) err = -ENXIO; if (sparx5->fdma_irq >= 0 && is_sparx5(sparx5)) { if (GCB_CHIP_ID_REV_ID_GET(sparx5->chip_id) > 0) - err = devm_request_threaded_irq(sparx5->dev, - sparx5->fdma_irq, - NULL, - sparx5_fdma_handler, - IRQF_ONESHOT, - "sparx5-fdma", sparx5); + err = devm_request_irq(sparx5->dev, + sparx5->fdma_irq, + sparx5_fdma_handler, + 0, + "sparx5-fdma", sparx5); if (!err) err = sparx5_fdma_start(sparx5); if (err)