From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D7BB08BE0 for ; Tue, 28 Mar 2023 15:08:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4DE90C433EF; Tue, 28 Mar 2023 15:08:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1680016087; bh=uuM4XBtYW5w9jZkoNWMYEJHVqnGUNgx3ZCZryf/qqIM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=B0KRCP/X2slm09GBitI8yI5KXiHkP9z16uViVM1AlBWjRKcvCBxPBrlKPF19RXbBV le1uvOVLDiUlmGEZsAHBPCBRwlYathpA5c96NG45/fSgu1P60JtsQGLcXczCM9mavv lyidC+Bjpz6hIvy3AxYM0xbEyDRuDB9FLzBW36z0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Joshua Washington , Simon Horman , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.15 059/146] gve: Cache link_speed value from device Date: Tue, 28 Mar 2023 16:42:28 +0200 Message-Id: <20230328142605.173330538@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230328142602.660084725@linuxfoundation.org> References: <20230328142602.660084725@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Joshua Washington [ Upstream commit 68c3e4fc8628b1487c965aabb29207249657eb5f ] The link speed is never changed for the uptime of a VM, and the current implementation sends an admin queue command for each call. Admin queue command invocations have nontrivial overhead (e.g., VM exits), which can be disruptive to users if triggered frequently. Our telemetry data shows that there are VMs that make frequent calls to this admin queue command. Caching the result of the original admin queue command would eliminate the need to send multiple admin queue commands on subsequent calls to retrieve link speed. Fixes: 7e074d5a76ca ("gve: Enable Link Speed Reporting in the driver.") Signed-off-by: Joshua Washington Reviewed-by: Simon Horman Link: https://lore.kernel.org/r/20230321172332.91678-1-joshwash@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/ethernet/google/gve/gve_ethtool.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/google/gve/gve_ethtool.c b/drivers/net/ethernet/google/gve/gve_ethtool.c index 878329ddcf8df..6a0663aadd1e9 100644 --- a/drivers/net/ethernet/google/gve/gve_ethtool.c +++ b/drivers/net/ethernet/google/gve/gve_ethtool.c @@ -526,7 +526,10 @@ static int gve_get_link_ksettings(struct net_device *netdev, struct ethtool_link_ksettings *cmd) { struct gve_priv *priv = netdev_priv(netdev); - int err = gve_adminq_report_link_speed(priv); + int err = 0; + + if (priv->link_speed == 0) + err = gve_adminq_report_link_speed(priv); cmd->base.speed = priv->link_speed; return err; -- 2.39.2