From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta0.migadu.com (out-33.mta0.migadu.com [91.218.175.33]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1503252CCF8 for ; Tue, 13 Oct 2026 17:59:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.33 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791914387; cv=none; b=ocplZs7T/Q3xssjt4gcLIIO/SiDSanm02J32PdGcH+6ILTK8rGsk1DYUaDNg1AoDfNhudZK5MABFGYjrRwgRrCE422QRLUYt0mIxGewNrm3M29LYXHrQ57cTfZrcIqiXh4IZHWAzMD+lpzUnXXjiTAXM7AvBi9iVqUZouR5BZdQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791914387; c=relaxed/simple; bh=KzjAP5mj+qZ64QCBziF9G7xxImjiEPrykcdJXSVUj50=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=M7ALmpAm+JVdfw0p4jiy5EwrLpEvCK45bHmFVU8haKAOZtYLKkgedWzrQ1ngeew8sKuVmQ1i95GTR/Fmj5nkzSjt1/SqYmnEU42r8O3CXQ+3WGO3hIDsnTV72JPYPig9sDdYoKEzEgJ3th3mraLsBVn9rXQdD2E342jSN0G8qmQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=O17l5H2j; arc=none smtp.client-ip=91.218.175.33 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="O17l5H2j" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=KzjAP5mj+qZ64QCBziF9G7xxImjiEPrykcdJXSVUj50=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1791914384; v=1; x=1792519184; b=O17l5H2j3eE7tzn8zHzdxnqA8EkbnR74B/up+BX6OliTHCM9wXlvruSLXYigcN8lOW8fwsot DCGxknPpFss/f5RpvBR2wfXTdBJteStPCNCBpuTuQkBMc1VuBLMofhcjykc2wTiqRal1trOyByb TXiDu9rxcKX95cKZNWQ+ksmQ= X-Envelope-To: linux-kernel@vger.kernel.org Received: by mta11.migadu.com with ESMTPS id 24a1a4ad649bf6e8; Tue, 13 Oct 2026 17:59:43 +0000 X-Mizu-Trace-ID: 24a1a4ad649bf6e8 X-Migadu-Flow: FLOW_OUT From: wen.yang@linux.dev To: Sebastian Andrzej Siewior , Clark Williams , Steven Rostedt Cc: Eric Dumazet , Jesper Dangaard Brouer , Jakub Kicinski , Paolo Abeni , linux-rt-devel@list.kernel.org, linux-kernel@vger.kernel.org, Jason Xing , Jason Xing , Wen Yang Subject: [PATCH 05/15] net: optimize napi_schedule_rps() Date: Wed, 14 Oct 2026 01:58:39 +0800 Message-Id: <16487698a3046cdfb31f056d409b34ce3fc0516b.1791912669.git.wen.yang@linux.dev> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Eric Dumazet commit 821eba962d95806beb0440742c4062a9da8a386b upstream. Based on initial patch from Jason Xing. Idea is to not raise NET_RX_SOFTIRQ from napi_schedule_rps() when we queued a packet into another cpu backlog. We can do this only in the context of us being called indirectly from net_rx_action(), to have the guarantee our rps_ipi_list will be processed before we exit from net_rx_action(). Link: https://lore.kernel.org/lkml/20230325152417.5403-1-kerneljasonxing@gmail.com/ Signed-off-by: Eric Dumazet Cc: Jason Xing Reviewed-by: Jason Xing Tested-by: Jason Xing Signed-off-by: Paolo Abeni Signed-off-by: Wen Yang --- net/core/dev.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index a46caebb06f7..10a8883ae490 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4727,8 +4727,6 @@ static void trigger_rx_softirq(void *data) * * - If this is another cpu queue, link it to our rps_ipi_list, * and make sure we will process rps_ipi_list from net_rx_action(). - * As we do not know yet if we are called from net_rx_action(), - * we have to raise NET_RX_SOFTIRQ. This might change in the future. * * - If this is our own queue, NAPI schedule our backlog. * Note that this also raises NET_RX_SOFTIRQ. @@ -4742,7 +4740,11 @@ static void napi_schedule_rps(struct softnet_data *sd) sd->rps_ipi_next = mysd->rps_ipi_list; mysd->rps_ipi_list = sd; - __raise_softirq_irqoff(NET_RX_SOFTIRQ); + /* If not called from net_rx_action() + * we have to raise NET_RX_SOFTIRQ. + */ + if (!mysd->in_net_rx_action) + __raise_softirq_irqoff(NET_RX_SOFTIRQ); return; } #endif /* CONFIG_RPS */ -- 2.25.1